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The Green Bulding Handbook

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The Green Building Handbook

South Africa Volume 10

Materials and Technologies EDITOR Llewellyn van Wyk

CHIEF EXECUTIVE Gordon Brown

CONTRIBUTORS Llewellyn van Wyk, Andy van den Dobbelstein, Craig Martin,Dirk Conradie, Manfred Braun, Mandla Dlamini, Pravesh Debba, Chris Rust, Piet Vosloo, Stefan Szewczuk, Tichaona Kumirai, Jeremy Gibberd, Peter Kidger, Naalamkai Ampofo-Anti, Zonke Dumani

DIRECTORS Gordon Brown Andrew Fehrsen Lloyd Macfarlane

PEER REVIEWER Dr. R. Milford, Dr. D. Conradi, F. Fester, K. Bramwell, L. van Wyk

EDITORIAL ENQUIRIES LvWyk@csir.co.za PUBLISHER

LAYOUT & DESIGN Shanice Daniels

www.alive2green.com

PRODUCTION COORDINATOR Shannon Manuel DISTRIBUTION Edward Macdonald

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FOREWORD

uman beings have long inhabited the earth and as such, the need for shelter has always been top priority for their safety and comfort. The evolving socio-cultural dynamics (access to new materials, access to modern building technologies, rapid population growth and industrialisation) have resulted in humans being increasingly urbanised. Urbanisation for a number of reasons led to sophisticated and complex ways of building and occupying buildings. This has in itself brought about new challenges for architects and all those who are in the building value chain. Buildings structures have become a lot more sophisticated to service, or manage in sustainable ways. In this transformed thinking, today’s architect does not only have to think about space form and architecture; or about Sindile Ngonyama commodity; firmness and delight, but in doing so, needs to President: South African ensure that the design suite does not compromise any of the Institute of Architects (SAIA) following:• Environmental factors • Materiality • Structure • Passive performance • The use of natural daylight • Energy consumption (which is of crucial importance) Sadly, due a number of reasons; often architects tend to look at only a few of these above elements, resulting in unsustainable design methodologies leading to inhumane built environments, whereas in today’s technological advancements, various ingenious and innovative ways exist, for ensuring that all the aforementioned elements are incorporated in the design and building process. Ideally all architects and designers ought to appreciate that buildings need not only be ecologically sound, but also need to possess emotional aspects, so as to uplift and inspire their inhabitants. My parting shot and hope is that this issue of Green Building Handbook, will continue to challenge every SAIA member, to lead by example, in ensuring that sustainable ways of design are followed to the end, without compromising our client needs, and the related space users’ aspirations. It is these softer aspects which inspire people who use buildings that we design. Thus I encourage all of our members to find ways to stitch all the afore-mentioned aspects together, in a way that brings harmony to both ends of this spectrum. If we overcome this challenge, we will be closer to achieving sustainable architecture, and we will certainly be moving towards the direction of achieving humane built environments!

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T

FOREWORD

he handbook brings together various strands of applied research concerning sustainability and adaptability in the built environment especially with regards to smart infrastructure. Both entails similar concerns, provide complementary tools and try to bridge the gap that may exist between and amongst building science and engineering, national interest and implementation. This handbook is bridging the gaps, creates synergies between the various research strands, intergrating and reconciling research ideas and providing guidance and insight for interested parties, where appropriate, at the appropriate scales. The sustainability and adaptability research concerns itself with socio-economic, environmental and infrastructure challenges, most notably energy and materials (sustainability) efficiencies. The research to date has tried to identify areas that can reduce carbon emmissions (energy efficiency), comfortability Dr. Cornelius Ruiters Executive Director: Built Environment and resources management. Collectively, the research CSIR provides information and processes that can be used as general guidelines for mitigation and sustainability at the most appropriate scale. The researchers in this edition have begun to explore sustainability and adaption in relation to climate change and resource management â&#x20AC;&#x201C; the necessary steps to be taken to prepare for more frequent occurrences of high impact events or circumstances. Researchers on local adaptation, content and responses to change is identifying how existing systems and infrastructure can be changed to reduce vulnerabilities. Various scenarios and research studies have indicated that sustainability and adaptability are important sustain (energy and water) infrastructure systems. Furthermore, infrastructure systems may need to change to address â&#x20AC;&#x153;green energyâ&#x20AC;?, development of local infrastructure systems and wetlands to deal with water runoff and even more sophisticated, large scale water treatment and supply systems to deal with AMD. The Smart Infrastructure research strand is consistent with strategies to adapt to variable and changing society, environment and climate. However, such infrastructure may increase demand and otherwise underline smart growth goals. But Smart Infrastructure and Smart growth research focuses on changes in the use of material and land in order to improve the quality of life within the broader context of social, economic and environmental change. From this research are emerging tools and frameworks as well as recommendations to guide decisions on infrastructure systems and services. Smart Infrastructure and growth research are needed to make reference to the larger environmental benefits that investments and policy decisions may bring. As a consequence, smart infrastructure and smart growth at the local scale make valuable contribution to socio- economic and environmental (sustainable) conditions at regional, national and global scales.

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EDITOR’S NOTE

Llewellyn van Wyk Editor

A

lthough not explicitly stated, green building rating systems fundamentally aim to improve building performance albeit with a bias toward environmental issues. Thus LEED promotes its system as being “resource efficient” reducing water and energy use and lowering greenhouse gas emissions . In promoting the new LEED system the United States Green Building Council notes that “by integrating technical and living systems, the team can achieve high levels of building performance, human performance, and environmental benefits.” The benefits of improving building performance have also been noted within the U.S. Congress who has established the High-Performance Buildings Caucus of the U.S. Congress (HPBCCC) to support the development of private sector standards, codes and guidelines. Defining high performance building is quite challenging: The US Government Public

Law 110-140 December 19, 2007 “Energy Independence and Security Act of 2007” (121 Stat 1598, para. 12) defines high-performance building as follows “High-performance building means a building that integrates and optimizes on a life cycle basis all major high performance attributes, including energy conservation, environment, safety, security, durability, accessibility, cost-benefit, productivity, sustainability, functionality, and operational considerations” while the High-Performance Building Council (HPBC) adopted the following definition for high-performance buildings “High-performance buildings, which address human, environmental, economic and total societal impact, are the result of the application of the highest level design, construction, operation and maintenance principles – a paradigm change for the built environment.” More recently resilience has been included in the definition: “high-per formance requirements that affect resiliency for

THE GREEN BUILDING HANDBOOK

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Editor’s Note Continued..

buildings have come under development” through a focus on “new advanced materials and products that exhibit comprehensive high-per formance attributes”. Not surprisingly the two concepts, i.e. green building and high performance building have been combined with a new focus on high performance green building. To this end an Office of Federal High-Performance Green Buildings has been launched to, inert alia, catalyse and facilitate the Federal government to operate more efficiently and effectively, and lead the marketplace to sustainability, by minimizing the Federal footprint through efficient use of energy, water, and resources, and by creating healthy productive workspaces”. I t seems to this writer that the focus should, quite correctly, be on performance. It also seems to this writer that the concept of performance in the building industry is poorly understood, especially if compared to the automotive

EDITOR’S NOTE and aeronautical industries, for example. This begs the question: how can a building be designed if the designer does not know how the building should and will perform? In this edition of the green building handbook some of these issues are discussed. The chapters address various themes – including energy efficiency, human comfor t, use of advanced technologies, smart buildings – through, in some instances, actual case studies. Readers will notice that the handbook has also increased it field of subject to include green infrastructure, and materials and methods. Whereas these subjects were previously presented in separate publications, it is believed that a single consolidated publication will provide the reader with a more comprehensive understanding of the integrated nature of these subjects. I wish to thank the contributors for their contributions, and the peer reviewers for ensuring that the standard of publication remains at an acceptable level.

Sincerely Llewellyn van Wyk Editor

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CONTRIBUTORS

LLEWELLYN VAN WYK Llewellyn van Wyk graduated in 1980 from the University of Cape Town with a Bachelor of Architecture degree. He opened his practice in 1984 completing building projects throughout Southern Africa. He joined the CSIR in 2002 and is currently a Principal Researcher in the Built Environment Unit.

ANDY VAN DEN DOBBELSTEEN Andy van den Dobbelsteen (Tilburg, the Netherlands, 1968) is full professor of Climate Design & Sustainability at the Faculty of Architecture & the Built Environment of the Delft University of Technology (TU Delft), the Netherlands. He chairs the facultyâ&#x20AC;&#x2122;s Department of Architectural Engineering + Technology and coordinates several international collaborations.

DR CRAIG LEE MARTIN Dr Craig Lee Martin began his academic career at The Manchester School of Architecture (MSA, UK). As Head of Technology at the MSA his primary motivation was to increase the architectural awareness of climate change, and to create an educational environment and attitude that could respond to it at all scales of design enquiry.

DIRK CONRADIE Dirk is a senior researcher in CSIR Built Environment Unit. He originally trained and practised as an architect but later specialised in systems and software related to the built environment. He is currently part of a research group that focuses on predictive building performance analysis. He can also be viewed as one of the CAD pioneers in South Africa.

MANDLA DLAMINI I am a Research engineer focusing on construction materials and methods. I am interested in alternative, green and sustainable technologies for the built environment. My work ranges from research and development of alternative cements like fly ash based Geopolymers to the recycling of greywater through constructed wetlands.

PROFESSOR PRAVESH DEBBA Professor Pravesh Debba is currently the Manager of Spatial Planning and Systems within the Built Environment at the Council for Scientific and Industrial Research (CSIR). Prior to joining CSIR in 2008, he was an Associate Professor in Statistics at the University of South Africa (UNISA).

CHRIS RUST Chris Rust holds a PhD in Civil Engineering from the University of the Witwatersrand and is currently the Strategic Innovation Manager at the CSIR Built Environment Unit. He is a registered professional civil engineer and has 35 yearsâ&#x20AC;&#x2122; experience in research in infrastructure related topics.

22

THE GREEN BUILDING HANDBOOK


PIET VOSLOO

CONTRIBUTORS

Piet Vosloo is an Associate Professor in the Department of Architecture at UP where he teaches mainly on environmental sustainability, green infrastructure and building construction. He holds degrees in architecture and landscape architecture and practices in both disciplines at kwpCREATE where he is a director.

STEFAN SZEWCZUK Stefan Szewczuk holds an MSc degree in Mechanical Engineering from the University of the Witwatersrand and an MBA from Herriot-Watt University He is a Senior Engineer at the CSIR and has worked on a wide range of projects around the world on behalf of the World Bank, UNDP, GEF and the EU. Stefan's interests include wind and renewable energies. TICHAONA KUMIRAI Tichaona Kumirai is a researcher at the Architectural Engineering research group of the CSIR. Kumirai has been at CSIR for four years. His research focuses on cutting down conventional energy used for providing indoor thermal comfort conditions in buildings through application of passive techniques. He holds a Masters degree in Mechanical Engineering.

JEREMY GIBBERD Jeremy Gibberd is an Architect with interests in sustainability, inclusion, sustainable built environments, community and education buildings. He has developed a range of tools, guides and training for government, the private sector and the UN on urban sustainability, sustainable buildings, sustainable facilities management and sustainable materials.

PETER KIDGER Peter Kidger is Director of Marketing at Corobrik. The pursuit of more energy efficient built environments has led to his engagement with considerable research to better understand the comparative performance of different wall construction types and the contribution of brick and brickwork for achieving sustainable outcomes.

NAA LAMKAI AMPOFO-ANTI Naa Lamkai Ampofo-Anti was born and educated in Ghana. She practised as an Architect in Ghana, Nigeria and Cameroon before immigrating to South Africa in 1990. She joined CSIR BE in 2005 and currently holds the position of senior researcher. Her research speciality is the use of Life Cycle Assessment (LCA) methodology to evaluate the environmental performance of buildings.

ZONKE DUMANI My name is Nozonke Dumani. I have completed both BSc and MSc in Chemical Engineering at the University of Cape Town. I am currently working at CSIR in the Built Environment unit as candidate researcher.

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CONTENTS GREEN BUILDING DESIGN STRATEGIES

1 2 3 4

Smart and bioclimatic design foe energy renovations of buildings: Case of the Pret-a-Loger House Andy van Dobbelstein & Craig Martin

28

A sultry afternoon in a naturally ventilated office during the hottest summer on record Dirk Conradie

48

High-performance green buildings: Towards a conceptual framework Llewellyn van Wyk

64

GBCSA: Green building certification tools across most sectors Manfred Braun

82

SUSTAINABLE INFRASTRUCTURE

5

Designing a constructed wetland Mandla Dlamini

6

Smart infrastructure reserach: the way ahead for South Africa Pravesh debba and Chris Rust

7

92

Mitigating against the time-of-use tariff by the commercial building sector 24 Stefan Szewczuk

100

122

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25


LIGHT GREEN OR DARK GREEN? LIGHT GREEN OR DARK LIGHT GREEN OR DARK GREEN? GREEN?

CONCEPT CONCEPT CONCEPT CONCEPT

We We We We

TO TO TO TO

COMPLETION COMPLETION COMPLETION COMPLETION

specialise specialise specialise specialise

in in in in

OF OF OF OF

PROJECT PROJECT PROJECT PROJECT

Lodges Lodges Lodges Lodges

ar ar gi gi tt e ek k .co.za .co.za .co.za

www. www. www. Architecture

• II n Architecture • n tt ee rr ii o o rr Architecture • Interior eFcGtR u *A M ErMcBh E Ri St O E ErN eB U I L D I N • G C O U N C IILn* RtEeG IrS iTo E RrE D

• G • G rr aa p ph h ii cc ss • Graphics GLrAaR p P R O F• ESSIONA C Hh I TiEcC TsS

*MEMBERS OF GREEN BUILDING COUNCIL *REGISTERED PROFESSIONAL ARCHITECTS *MEMBERS OF GREEN BUILDING COUNCIL *REGISTERED PROFESSIONAL ARCHITECTS *MEMBERS OF GREEN BUILDING COUNCIL *REGISTERED PROFESSIONAL ARCHITECTS


CONTENTS 8

132

Green Walls - Fashionable or Functional Stefan Szewczuk

GREEN BUILDING MATERIALS & TECHNOLOGIES

9 10 11 12

Phase changing materials (PCMs) - application in buildings for human thermal comfort Tichaona Kumirai

142

Local content - supporting local economies Jeremy Gibberd

158

Corobrick - Specifying for superior thermal performance with wall constructions Peter Kidger

170

Overview of floor coverings Naalamkai Ampofo-Anti & Zonke Dumani

180

MATERIALS & TECHNOLOGIES DIRECTORY

192

Steel

194

Paint

197

Waterproofing

200

Architectural Glass

202

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27


PROFILE: BASF

SLENTITE®: Successful piloting of new high-performance insulation material for customized climate management

SLENTITE®, BASF’s new high-performance insulation material, is now entering its market preparation phase. After the commissioning of the pilot plant for the production of sample quantities in June 2015, the production process for the novel PU aerogel has advanced to the next level. In March 2016, SLENTITE was exhibited for the first time in an application of a cooperation partner. At “Frontale”, the biggest European trade show for window construction, doors and facades in Nürnberg, possible applications were presented in two Beck+Heun products. Customized climate management for energy upgrades In the design and construction sectors, the properties of SLENTITE are opening up totally new potential. The innovative material based on a polyurethane (PU) aerogel is manufactured as a heavy-duty panel displaying exceptional insulation performance. Owing to its open-porous structure, the material provides moisture regulation and thus contributes to a pleasant interior climate: Customized climate management with the new highperformance insulation material. SLENTITE delivers an optimal package of all the key properties of an efficient and futuristic insulation material for new buildings and for the energy upgrade of existing ones. Inserted between the window frame and the masonry, SLENTITE makes window modernization even more attractive. The PU aerogel can be installed as thermal insulation wedges between walls and windows indoors and outdoors, regardless of the window frame material. “We now have the chance to eliminate thermal weak points in the building envelope, prevent damage, and

enhance interior comfort,” says Dr. Marc Fricke, SLENTITE Project Manager at BASF Polyurethanes. Constructing Tomorrow: Superlative insulation values for the buildings of the future Architects, designers, and clients are constantly on the lookout for new materials that insulate buildings efficiently and also open up scope for creativity. At the same time, materials have to meet high standards of sustainability, resource efficiency and interior climate – in new and modernized buildings. This is where SLENTITE delivers further product improvements. Jesper Bjerregaard, Director Marketing Construction and responsible for the SLENTITE market launch, is convinced of the success of the new product: “With our new high – performance insulation material, we can offer the market a variety of possible solutions for the challenges of the future. In the construction sector there is big demand for innovative approaches, novel construction materials, and above all sustainable strategies for residential interiors. With SLENTITE we can meet the requirements for forwardlooking architecture and infrastructure.

Dr. Marc Fricke, SLENTITE® Project Manager at BASF Polyurethanes and Jesper Bjerregaard, Director Marketing Construction, in the SLENTITE pilot plant

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29


Smart and Bioclimatic Design for Energy Renovations of Buildings

The case of the Pret-a-loger house Andy van den Dobbelsteen & Craig Lee Martin


1

Abstract

In the light of the Paris Climate Treaty the built environment needs to become e n e rg y n e u t r a l w i t h i n t h e c o m i n g decades. In Europe, by 2020 newly built buildings already need to be ‘nearly zeroenergy ’, but with the current European rate of new construction less than 1% of new sustainable buildings will be added to the market. Thus, in fifteen years’ time around 10% of the built environment will meet high sustainability standards. 90% of the built environment of 2030 is already here now, mak ing energy renovation of existing buildings much more effective than constructing zeroenergy new ones. I n c o u n t r i e s l i k e S o u t h Af r i c a t h e ratio between old and new may more f a v o u r a b l e, b u t a l s o h e re, e n e rg y renovation will be more effective than constructing new zero-energy buildings. Smar t & Bioclimatic Design (S&BCD) may be a method suited to energy renovation, making optimum use of the local circumstances in the re-design of existing buildings. Taking into account the local climate and its expec ted changes in the coming decades will demand a smart retrofit plan. For the Solar Decathlon Europe 2014 c o m p e t i t i o n ( S D E 2 0 1 4 , Ve r s a i l l e s , France), the TU Delft student team, led by the authors, used the S&BCD method to renovate an existing terraced house. The house, representative for 1.4 million d we l l i n g s i n t h e N e t h e r l a n d s, w a s given a new sk in that included smar t technology and enabled the continued accommodation of inhabitants, hence t h e n a m e Prê t - à - Lo g e r ( ‘re a d y t o inhabit ’). Mak ing optimum use of the temperature -stable underground, a s o l a r- o r i e n t a t e d g l a s s h o u s e a n d smar t technology turned the energyinefficient, uncomfor table and small

SMART & BIOCLIMATIC DESIGN

house into a zero-energy, fossil-free one with healthy indoor conditions and extra living quality. The Prêt-à-Loger project won five awards at the SDE2014, among which the much coveted first prize for sustainabilit y. After the competition the prototype was rebuilt at the TU Delft campus, functioning as a demonstration object and office. The S&BCD method can also be implementable for energy renovation in South Africa, although it would lead to different measures. Compared to the Netherlands, South Africa has a wider variety of generally warmer and drier climates, so using S&BCD here would inevitably lead to different potentials, restrictions and design solutions. Nonetheless, with the severe climate and energy challenges of the near future, inter ventions are urgently needed, and S&BCD can provide the best local tools for it. 

Introduction

In the light of the Paris Climate Treaty the built environment needs to become e n e rg y n e u t r a l w i t h i n t h e c o m i n g decades. In Europe, by 2020 newly built buildings already need to be ‘nearly zeroenergy ’, but with the current European rate of new construction less than 1% of new sustainable buildings will be added to the market. Thus, in fifteen years’ time around 10% of the built environment will meet high sustainability standards. 90% of the built environment of 2030 is already here now, mak ing energy renovation of existing buildings much more effective than constructing zeroenergy new ones. I n c o u n t r i e s l i k e S o u t h Af r i c a t h e ratio between old and new may more f a v o u r a b l e, b u t a l s o h e re, e n e rg y

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31


SMART & BIOCLIMATIC DESIGN

1

renovation will be more effective than constructing new zero-energy buildings.

Smart & Bioclimatic Design Climate design and sustainability The climate design of buildings encompasses the realisation of a comfortable indoor and outdoor environment. Sustainable climate design aims at doing this with the minimal consumption of energy and mitigated environmental effects. It is an expertise that integrates the basic knowledge of building physics and building services into the area of architectural design, with a focus on sustainable solutions for energy and comfort. Due to energy resource depletion and the demand for healthier indoor and outdoor environments, there is a growing need for a more sustainable climate design of buildings. There are several approaches to this, among which smart design and bioclimatic design. Smart & bioclimatic design Smart & bioclimatic design was coined as an architectural design approach and related to education in a paper by Dobbelsteen & Linden [2007]. Smart design is a term with different meanings, based on the sources used. When ‘smart’ is related to the term ‘intelligent’, which comes from Latin (‘intelligens’ = distinctive, selective), it can refer to natural or artificial intelligence. Natural intelligence is a natural generic cognitive ability to reason with underlying processes in a conventional way. Artificial intelligence is the theoretical stream in informatics and psychology that aims at a perfect imitation of intelligent human behaviour by a computer. In terms of building, building management systems attempt to match this cognitive reaction: through specific programming input is processed (via sensors) to a desired output [Timmeren 2001]. Over the last decades the

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meaning of smart design and specifically smart architecture [Hinte et al. 2003] has shifted towards sustainable designs that intelligently interact with the environment. Incited by environmental concerns and the physical logic behind a more intelligent way of designing buildings, which are attuned to the local climate, brothers Victor and Aladar Olgyay explored what they coined bioclimatic design in the 1950s. The basis for bioclimatic architecture was laid in Victor Olgyay’s epic 1963 work Design with Climate: Bioclimatic Approach to Architectural Regionalism [reused as: Olgyay 2015]. The Malaysian architect Ken Yeang defined bioclimatic design as “the passive low-energy design approach that makes use of the ambient energies of the climate of the locality (including the latitude and the ecosystem, through siting, orientation, layout and construction) to create conditions of comfort for the users of the building” [Yeang 1999]. The combination of both terms – smart and bioclimatic design (S&BCD) – encompasses a design approach that deploys local characteristics intelligently into the sustainable design of buildings and urban plans [Dobbelsteen & Linden 2007]. These local characteristics can refer to natural circumstances (the climate, seasonal changes, variety of the weather, diurnal differences, geomorphology, etc.) and to anthropogenic interventions (such as the designed landscape, cultural, historical and technical features, and the built environment). The difference with a more traditional approach to architectural (or urban) design is that before putting anything on paper (or into the computer), S&BCD explicitly propagates a thorough analysis of climatic conditions, local circumstances and the intended use of a building or urban area: • Step 1: formulate starting conditions • Step 2: analyse local characteristics • Step 3: define boundary conditions and strategies for design


1 â&#x20AC;˘ Step 4: design smartly Following this hypothesis will lead to a more sustainable and energy-efficient building design that better satisfies the needs of its users. S&BCD in education At the Faculty of Architecture of Delft University of Technology, S&BCD has become the central approach to sustainable climate design of buildings. Beginning with only an elective course eleven years ago, it is presently being conve yed in undergraduate education during the first year of the BSc curriculum. Students are taught to apply S&BCD in their design, firstly to respond to the changing global energy situation, and secondly to adhere to strict EU regulations for NZEB in 2020 that demand a different attitude towards the built environment. In addition to new buildings, S&BCD is a suited method for energy renovation, mak ing optimum use of the local circumstances in the re-design of existing buildings. This may help to make an effective energy transition in the built environment. Next to our future energy security, it has importance for the liveability of the inhabitants. Taking into account the expected climate change in the coming decades a smart retrofit plan is required that better responds to the circumstances of the near future. According to the International Panel on Climate Change [IPCC 2014] for most regions in the world this entails higher temperatures, greater intensity in droughts and precipitation, and more extreme events such as storms. Solar Decathlon Europe 2014 A brief background of the Solar Decathlon The Solar Decathlon was initiated in the early 2000s by the US Department of Energy, in order to stimulate the development of energetically selfsufficient houses, fully based on solar. It is a competition between university

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teams that build their own solar house on a designated site, where they are measured and tested for two weeks, on ten criteria, hence the decathlonâ&#x20AC;&#x2122;s name. The Solar Decathlon started as a bi-annual competition in the USA, similar follow up events (endorsed by the US organisation) in Europe, Asia and Latin America have since taken place in the intermediate years, Europe has so far hosted three Solar Decathlons: two in Madrid, Spain (2010 and 2012), and one in Versailles, France (2014). Apart from the competition element, the Solar Decathlon is primarily an educative event in which new sustainable developments in housing and solar applications are promoted and fully explored. It brings together communities of academics, students and companies in the field of sustainable building, who actively par take in the construction, operation and deconstruction of the competing dwellings. Those activities tak ing place next to an interested audience and press, who are allowed to visit the terrain and be inspired. SDE2014 The Solar Decathlon Europe 2014 competition (SDE2014) was held in Ve r s a i l l e s, Fr a n c e. Th e o rg a n i s i n g c o m m i t te e c h a l l e n g e d u n i ve r s i t i e s worldwide to come up with solutions for local societally urgent issues. The twenty finalists, allowed to construct their house on a forgotten corner of the premises of the Versailles palace gardens, demonstrated a focus on issues of density in cities, social housing, disaster building and re-use. It was an event well covered by national and international media, and it attracted some 150,000 visitors, who were offered tours through the different houses. The competition lasted two weeks, after which the terrain was left vacant again.

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Of the competitors, the TU Delft student team, led by the authors, provided the only entry of a renovation plan for an existing dwelling, called Home with a Skin, or Prêt-à-Loger, ready to inhabit.

space limitations and energy wastage, all of which presenting owners with high energy bills and concerns regarding the viability of their homes.

Figure 01: The original terraced house in the Dutch town of Honselersdijk, constructed in 1960.

The result of the Delft team The Prêt-à-Loger team used the S&BCD method to demonstrate a sustainable renovation of one existing terraced house, modelled upon a real 1960 dwelling in the western town of Honselersdijk, the Netherlands. More than just the technical renovation of an existing structure, the project was aiming for an improvement of the lives of families, giving them a healthy and comfortable home, with extra space and no energy bill [Dobbelsteen et al. 2015]. The students communicated their plans with local inhabitants of Honselersdijk and used their responses and suggestions to improve the concept. Most of the furniture in the completed house was kindly and fittingly donated by people from the Honselersdijk neighbourhood.

Rationale behind Prêt-à-Loger In strong contrast to previous decathlon entries, which could be arguably characterised as flashy futuristic solar pavilions, the TU Delft students imagined a greater challenge that lies in the approach of the existing Dutch housing stock. There are approximately 7 million dwellings in the Netherlands, most of which were constructed after World War II. As a consequence, a significant percentage of these dwellings have a poor energy performance, their occupants having to contend with numerous sub-optimal circumstances. The TU Delft student team discovered that the main problem category of dwellings are terraced houses (so-called ‘rowhouses’) built between 1945 and 1975, of which there are 1.4 million in total. Typical issues encountered by these houses being moisture and mould ingress,

Figure 02 and 03: Artist impressions of what the eventual refurbished home should provide: no loss of the garden in summertime (left) and a ‘rough-climate’ buffer in wintertime (right). In the

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1 in-between seasons (no image) the sunspace has a pleasant temperature for living purposes, providing extra space.

The project, drawing visual attention by a glass house attached to the existing structure, finally won five awards at the SDE2014, among which the first prize for sustainability and for communication & social awareness. After the competition the prototype was rebuilt on the TU Delft campus, functioning as a demonstration piece and office. T h e S & B C D re f u rb i s h m e n t o f a typical terraced house Step 1: formulate starting conditions After the choice had been made to focus on post-war terraced houses, a real house from Honselersdijk was selected to serve as a model for the renovated prototype that would be competing in Versailles. Honselersdijk lies in the par t of the Netherlands called the Westland, famous for its intensive methods of horticulture that produce food and flowers for export all across the world. Large areas are covered with greenhouses, some of which as high as a two-stor y house. The orientation of the original house, n o r t h -we s t s t re e t s i d e a n d s o u t h east garden side, was copied for the protot ype, as well as the buildings dimensions. Later, due to regulations of the SDE2014 the stairs were broadened and the total height reduced to avoid shading of other teams. Apart from this, all measurements, layout and orientation were copied from the original, which did not make the assignment easy, but true to real-life circumstances, just like all existing situations are sub-optimal. The logical star ting point is a zero energy house, not necessar ily fully self-sufficient but energy-neutral over a year ’s time (the Dutch electricity grid

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allowing for the discharge of excess power). Step 2: analyse local characteristics Students were asked to meticulously analyse the local climate, underground and vicinity. A par t of this is discussed here. According to the Köppen-Geiger classification (figure 04a), The N e t h e r l a n d s h a s a m i l d te m p e r a te climate, fully humid, with warm summers (Cfb type). Compared to South Africa (figure 04b), which has a much more complex set of climates, the Dutch climate is relatively uniform.

Figure 04: Climate maps based on K ö p p e n - G e i g e r, a . fo r Eu ro p e ( t h e Netherlands left of the middle) [Peel et al. 2007] and b. for South-Africa [Conradie 2012]; below is the classification legend. The Dutch climate is strongly influenced by the Nor th Sea, giving the countr y relatively soft winters and cool summers and a mean annual temperature of around 10oC. The mean temperature is expected to rise with 1.0-2.3oC by 2050 [KNMI 2015]. Figure 05 gives trends in heating degree day numbers for the Netherlands (based on data from KNMI, the Royal Netherlands Meteorological Institute), which are decreasing but still demand additional heating in the winter season.

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Figure 05: Trends of heating degree days in the Netherlands, based on a reference temperature of 18oC [KNMI].

The climatic mean temperature implies that the soil, beneath one metre underground, is fluctuating around 10oC, rather stably (it never freezes or exceeds 20oC below a depth of 80 cm). Being part of a large delta area where the Rhine and Meuse rivers run into the North Sea, the country’s underground is built up from clay, peat, sand and salt depositions, enabling good heat exchange and creating layers of aquifers.

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Figure 06: Climate maps of the Netherlands, a. mean temperatures, b. precipitation, c. wind velocities [KNMI]. The red circle depicts the location of Honselersdijk.

Figure 06 shows three climate maps of the Netherlands. With its position next to the North Sea, the Dutch air is relatively humid, and the prevailing strong western or south-western winds (5 Beaufort on average) bring rain throughout the year, around 800 mm in total, though set to increase due to climate change. The Westland horticulture area produces a significant amount of secondary biomass, which is usually centrally processed for fertiliser, compost, biogas, or resource for bio-based products. Little being wasted in the current system. With the frequently overcast Dutch sky, energy yields from photovoltaic systems and solar thermal panels may seem limited, but the average active production of solar power or heat is not less than half the quantity of the best sited places on earth. In 2015 PV panels had a return on investment of less than ten years, without subsidies. The terraced house itself, finally, is reminiscent of a typical Dutch tradition of neatly aligned ‘rijtjeshuizen’, literally row-houses. They are also called ‘doorzonwoningen’, dwellings that have a transparent front and back façade, allowing crossventilation and the sun to reach deeply into the house. The house has a cavity wall, uninsulated (U value 2.557 W/m2K), with a load-bearing limestone inner blade and brick masonry on the outside. The original wood window-frame has single glazing (U = 6.258 W/m2K). Floor and roof


1 construction is timber-framed, which originally was uninsulated, but in the Honselersdijk case it had been given a layer mineral wool (U value 0.34 W/m2K). It has a chimney allowing a central hearth or old furnace. As in most cases, in the Honselersdijk dwelling this was replaced by a centralised heating system, served by a gas-fired boiler. Step 3: define boundary conditions and strategies for design Based on the analysis of local characteristics we could define boundary conditions for the house’s re-design. A few of these are discussed here. The Dutch mean temperature (around 10oC) still is ten degrees too cold for the desired indoor comfort temperature. Therefore, thermal insulation is desired in the building’s envelope to reduce heat transmission losses, and heat recovery on exhaust air is recommended to reduce ventilation losses. The 1960 example building has no thermal insulation in the outer cavity wall, and it only has exhaust ventilation in kitchen, toilets and bathroom, without heat recovery. Furthermore, it was a key strategy to allow passive solar energy (114 W/m2 or 1000 kWh/m2 per annum, horizontal plane) for at least three quarters of a year, utilising solar heat, especially in winter.

Figure 07: Solar chart for 52o northern latitude, typical for the Netherlands, with an indication of the orientation of the back (red) and front (blue) façade of the Honselersdijk terraced house [adaptation of KNMI].

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The Dutch underground provides plenty of energy potential. Aquifers 150-250 m deep are increasingly be used to store thermal energy interseasonally, for urban areas or buildings beyond 10,000 m2. For the smaller project of the Solar Decathlon this solution was ignored. Instead we chose to install ventilation pipes in the shallow soil to attract pre-cooled air in summer and preheated air in winter. However, confronted with SDE2014 regulations that forbid to excavate the ground, the effect of soil was replaced by phase change materials in the crawl space of the house. Due to the built-up density in the Westland area, large wind turbines are highly restricted, and the energy potential of urban wind turbines is small, around 500 kWh per turbine. Considering these factors it was decided against using a small urban wind turbines strategy. The use of natural gas needs to be avoided, necessitating an all-electric solution for the dwelling’s climate design. Aware that the greenhouses surrounding Honselersdijk have their own circular system of bio-based sources, and with the intent of avoiding fossil energy, it was decided that the sun was the only method of producing renewable energy. Hence, all potential in passive and active solar energy needed to be seized. For the house itself the team wanted to propose technical solutions that would still allow the inhabitants to remain in the building while installation took place. This entails preservation of elements that otherwise would require severe replacement activities and avoidance of interventions to the indoor structure. Replacement of nonstructurally integrated building services and interventions to the outer skin would be allowed. Step 4: design smartly Based on the boundary conditions phrased previously, the team of students and faculty advisors had multiple workshop sessions to get to a fit re-design of the Honselersdijk

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terraced house. An early decision was to add a new skin to the dwelling that would include all smart technology required to make it sustainable and self-sufficient, even including waste water treatment and food production. This concept was later made more realistic, when the idea of a greenhouse was entered to create more space, both for the dwellers as for photovoltaic arrays, and to maximise the yield of passive solar energy. Starting with the concept of a house under a large greenhouse, the eventual solution was a one-sided glass-house (on the southeastern elevation) that integrated a manifold of purposes, both energetic and functional.

Smart design of the Prêt-à-Loger house This section further elaborates on step 4 of S&BCD, the smart design based on boundar y conditions and strategies evolving from pre-research. The original house Figure 10 shows a cross-section of the original house from Honselersdijk. The drawing here is adapted from the original to comply with the SDE2014 regulations, in that the house height is limited to 7 metres, for which the attic was merged with the first floor. From this crosssection one can see the building’s concrete foundation (not visible are foundation piles into the ground, required in large parts of the Netherlands due to the peaty soil), timber floor and roof structure, uninsulated cavity walls with a limestone load-bearing inner gable and brick outer gable, and wood window-frames with single glass.

Figure 08: First idea of the Solar Decathlon project: to fold a new skin over the house with sustainable technology.

Figure 10: Original cross-section of the 1960 Honselersdijk house: concrete foundations, timber floor and roof structure, limestone – brick cavity wall, wood window-frames with single glass.

Figure 09: The preliminary version of the redesign, with a greenhouse structure covering the exiting house, with a sun-space on the south-east, and green on the north-west.

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The New Stepped Strategy In the Netherlands, since the early 1990s the Trias Energetica [Lysen 1996] has been a widely used strategy for sustainable building: reduce the energy demand, use renewable energy sources, use non-renewables clean and efficiently. In ten years’ time there has been insufficient improvement to the energy


1 performance of buildings. Part of this is due to a misunderstanding of the steps of the Trias Energetica. The New Stepped Strategy [Dobbelsteen 2008] was introduced to insert a step dealing with residual energy. The news steps are: 1. reduce the demand, 2. reuse waste flows, 3. use renewable sources and let remaining waste be food. The third step thus also discourages the disturbance of the natural environment, based on the Cradle to Cradle theory [McDonough & Braungart 2002]. Reducing the demand (NSS step 1) Using the New Stepped Strategy (NSS) [Dobbelsteen 2008], the first step is to reduce the demand for energy by urban or architectural measures that do not require technical utilities: orientation, zoning, compartmentalisation, thermal insulation, accumulative building mass, daylight access. Having to deal with an existing house, the options are limited when attempting to improve thermal insulation and daylight access.

Figure 11: Adding thermal post-insulation to the existing house.

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removal of the outer blade, the post-insulation on this cold side leads to an addition of only 10 cm wall thickness. On the south-east side, vapour-open thermal insulation is inserted into the 5 cm wall cavity; the glasshouse introduced later further improves (lowers) the U value. Finally, the ground floor is well-insulated from the underside. Table 01 depicts the U-values (and other properties of glazing) of the original 1960 house in Honselersdijk, and those of the Prêtà-Loger renovation plan. Table 01: U values and other properties of the original Honselersdijk house and the Prêt-àLoger renovation.

Figure 12 shows the replacement of single glazing (U value of 6.3 W/m2K) by HR++ glass (U = 0.78 W/m2K) and the introduction of ‘Solatubes’, sun and daylight catchers with reflecting canals that bring daylight deep into the house. Triple glazing was not chosen as this would have led to heavier and deeper window-frames, elements that are difficult to integrate into the existing structure.

Figure 11 depicts the measures regarding thermal post-insulation. Firstly, the roof is insulated from the inside, thicker on the northwest side (U value 0.14 W/m2K) than on the south-west (0.19 W/m2K). Secondly, the northwest façade is post-insulated with 25 cm of vapour-open natural fibre insulation, after removing the outer, non-load-bearing gable and sealing the insulation off with thin brick slips that resemble the previous and replaced façade (new U value 0.89 W/m2K). Due to the

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Figure 12: Placing HR++ glass panels plus introducing Solatubes to allow daylight deep into the dwelling.Reusing waste heat (Step 2)

Step two of the New Stepped Strategy deals with the reuse of waste heat coming from the house. Next to a heat-recovery tube in the bathroom’s shower (not visible), heat from exhaust air is recovered and transferred to incoming air by a ventilation unit with a heat exchanger. In order to fully optimise this system, incoming air was planned to be taken in through a ground collector of tubes, so that the air is pre-cooled in summer and pre-heated in winter (figure 13).

Figure 14: Placing HR++ glass panels plus introducing Solatubes to allow daylight deep into the dwelling. Producing energy from renewables(Step 3) The previous two steps had reduced the remaining demand for energy to a minimum. This is important, because when we get to the point that renewable energy sources come in, relatively big investments are needed and – in particular with solar energy – often there is not enough roof area to produce enough energy when the demand is still high.

Figure 13: Adding thermal post-insulation to the existing house.

As explained, the SDE2014 regulations did not allow for excavation of the Versailles ground, as an alternative the team opted to use PCMs in the crawl space (figure 14). This battery of long-phase melting salt could be used as pre-cooling device in summer (recharging by cooling down again at night). The opposite scenario, the PCM acting as pre-heater in winter, wasn’t possible as heat recharging would not work during this period. While the use of ground soil may have led to better performance, the PCMs were a good alternative considering the competition restrictions.

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Figure 15: The PV-integrated glass house, with heat collectors, heat pump and hot water tank.

Figure 15 illustrates how the Prêt-à-Loger team introduced half a greenhouse and positioned it against the south- east elevation of the dwelling; its structure is attached to the house’s chimneys. This glass house has several functions. Firstly, it ser ves as structure for photovoltaic cells, which are integrated into the glass panels of the roof and of the front


1 openings. The glass house provides more area for PV whilst still admitting light – and heat – into the sun-space. Secondly, an important function of the glass house is to capture heat. Next to directly usable passive solar energy, the cumulated heat in the space rises up to the roof, where an adiabatic collector takes away the heat, hence cooling the solar roof. After the heat has passed through a heat pump, it is stored in a hot water tank raising its temperature to around 55oC (a temperature suitable for showering). Following the post-insulation from the first step, this water temperature is now sufficient to be used in the (old, maintained) radiators of the domestic heating system.

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causing heat problems in summertime. With the Prêt-à-Loger house the aim was also to demonstrate how garden design can contribute to better ecology, food production and, not least, better living quality for the inhabitant. This work was achieved in collaboration with NL Greenlabel, a Dutch non-profit organisation that promotes sustainable gardening with local materials, indigenous plants and absence of toxic maintenance. Figure 17 shows the measures taken.

Figure 17: Final cross-section of the Prêtà-Loger house, Home -with-a-Sk in, with an indication of green measures.

Figure 16: The rainwater collection system. Figure 16 also indicates the location of a rainwater storage tank in the crawl s p a c e u n d e r n e a t h t h e g l a s s h o u s e. R ainwater is captured both from the glazed roof and the nor th-west green roof. Water captured from the house’s roofs is used for toilet-flushing and for watering the garden. Special attention to green 1960’s terraced houses typically have little greener y in the front and back garden: most of the ground is paved,

Final result The house, a re-constructed copy of the original house, was first constructed on the premises of the concept builder in Almelo, the Netherlands. This was a necessary stage, firstly to test the assembly of all components, fixtures and fittings, and secondly (and arguably the most important) to check that the construction time could be done within the maximum of 10 days, a stringent requirement of the SDE2014. The second time the house was built for the competition (sited on a remote corner of the gardens of the Versailles palace, France), the construction phase took no more than nine days (figure 18). This completion event drew much attention from the public, press and the team’s competitors, who showed their

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appreciation of a renovation concept that broke bravely from new solar decathlon competition tradition.

Figure 18: The Home-with-a-Skin during the Solar Decathlon Europe 2014 in Versailles, France.

After the competition the house was deconstructed within three days and constructed for a third time at the campus of TU Delft (figure 19). Officially opened by Stef Blok (Dutch Minister of Housing), the house has since welcomed hundreds of interested visitor groups, ranging from academics, municipalities, housing associations, companies, television crews, press and, not least, general public. Two years later, the project continues to resonate in publications on energy renovation, especially after the signing of the Paris climate treat.

Figure 19: Prêt-à-Loger at the campus of TU Delft, on the former site of the Faculty of Architecture.

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Performance measured Making optimum use of the temperature-stable underground (PCMs), solar-orientated glasshouse and smart technology turned the energy-inefficient, uncomfortable and small house into a zero-energy, fossil-free one with healthy indoor conditions and extra living quality. This was confirmed during the SDE2014 competition, where for instance the sub-optimal orientation of the house nonetheless led to a high performance in electricity production, aided by the glass-house heat collector system. As a result of the PCMs and well-functioning cross-ventilation of the glass-house the Home -with-a-Sk in managed to maintain a cooler temperature than the other houses, despite the searing heat of a several competition days. Since returning to Delft, the house has been the catalyst for numerous Master study graduation topics undertaken by former members of the Prêt-à-Loger team. These topics have related directly to the Home-with-a-Skin project or to energy renovations of differing building types. Topic examples being a comparative analysis of the simulated and real energy performance of the house itself [Xexakis & Dobbelsteen 2015], and an exergetic analysis study, devised to enhance systems used in the Home-with-a-Skin [De Leo 2016]. General findings were that the house per formed according to expectations, though joints and seams in connecting walls, floors and roofs have inevitably suffered damage from being constructed three times (and deconstructed and transpor ted twice). Nonetheless, as measured by the students mentioned, the Home -with-a-Sk in is still energy neutral and can be justifiably called the most sustainable terrace house in the


1 world, a title it won af ter winning the sustainabilit y award at the SDE2014. 6. Conclusion Success The Prêt-à-Loger project demonstrated the great value of a smart and bioclimatic design approach for existing houses, buildings that originally had been designed without account of local characteristics, consequently failing to seize opportunities for energy saving and sustainable solutions around the house. A zero-energy renovation has been successfully built in the largest and most demanding housing competition in the world. The TU Delft team have proved that living standards can be extensively enhanced and realised in existing contexts with minimal disturbance and maximum environmental benefit. South Africa The ratio between old and new houses in South Africa may, as with the Netherlands, favour energy renovation over the construction of new zero-energy buildings. Compared to the Netherlands, South Africa has a wider variety of generally warmer and drier climates, using S&BCD here would inevitably lead to different potentials, restrictions and design solutions. Nonetheless, in response to the severe climate and energy challenges of the near

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future, interventions are urgently needed, and S&BCD can provide the best local tools for it. The best way to get it started is to approach one example of a typical SouthAfrican unsustainable house, valued by its users sentimentally and economically, and demonstrate how it can be improved. The authors hope such an opportunity arises soon, and offer their expertise to help such a project forward. 7. Acknowledgements We are very grateful to all the students of the Prêt-à-Loger team, the best students we could have ever delivered; special thanks to primus inter pares Tim Jonathan. We also want to thank our partner in crime, professor Hans Wamelink, the faculty advisor who was equally involved in the project and who guided the construction process. Furthermore, we like to express our gratitude to all institutions and companies that were partner to the Solar Decathlon project and that helped to make it such a huge success. There were too many partners, sponsors and supporters to be mentioned, but we want to name the biggest contributors: TU Delft, TBI, Ministry of the Interior and Kingdom Relations, Univé verzekeringen, Putman/ Solar Compleet/Technische Unie, DMEGC, EIT Climate-KIC, and Van Dorp Installaties.

References

• Conradie D.C.U.; South Africa’s Climatic Zones: Today, Tomorrow; Proceedings International Green Building Conference and Exhibition, Sandton, South-Africa, 2012 • De Leo G.; Graduation thesis; Delft University of Technology, 2016 • Dobbelsteen A. van den; ‘Towards closed cycles – New strategy steps inspired by the Cradle to Cradle approach’, in: Proceedings PLEA 2008 – 25th Conference on Passive and Low Energy Architecture (CD-rom); UCD, Dublin, 2008

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• Dobbelsteen A. van den & Linden K. van der; ‘Self-directing learning – Getting students to learn effectively about smart and bioclimatic design’, in: PLEA 2007 – Sun, Wind and Architecture (816-821); NUS, Singapore, 2007 • Dobbelsteen, A. van den, Jonathan T. & Kruizinga J.; ‘Prêt-à-Loger: Zero-Energy Home with Maximum Living Quality Increase’, in: Proceedings of Architecture and Resilience on a local scale (AR2015); University of Sheffield, 2015 • Hinte E. van, Neelen M., Vink J. & Vollard P.; Smart Architecture; Rotterdam: 010 Publishers, 2003 • IPCC (Intergovernmental Panel on Climate Change); Climate Change 2014: Impacts, Adaptation, and Vulberability; IPCC, Switzerland, 2014 • KNMI (Koninklijk Nederlands Meteorologisch Instituut); www.knmi.nl, accessed 2016 • KNMI (Royal Netherlands Meteorological Institute); KNMI Climate Scenarios for the Netherlands ’14; KNMI, De Bilt, 2015 • Lysen E.H.; ‘The Trias Energetica – Solar Energy Strategies for Developing Countries’, in: Proceedings of the Eurosun Conference (); Freiburg, 1996 • Olgyay V.W.; Design with Climate: Bioclimatic Approach to Architectural Regionalism (new and expanded edition); Princeton University Press, 2015 • Peel M.C., Finlayson B.L. & McMahon T.A.; Updated world map of the Köppen-Geiger climate classification; Hydrology and Earth System Sciences 11 (1633-1644), 2007 • Timmeren A. van; High-tech, low-tech, no-tech; Delft: TU Delft, 2001. • Yeang K.; The Skyscraper: Bioclimatically Considered: A Design Primer; London: John Wiley & Sons, London, 1999. • Xexakis G. & Dobbelsteen A. van den; ‘The Gap between Plan and Practice: Actual Energy Performance of the Zero-Energy Refurbishment of a Terraced House’, in: Proceedings of Architecture and Resilience on a local scale (AR2015); University of Sheffield, 2015

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Our achievements: • 100% success rate with Green Star certifications • FNB Freedom Plaza, Namibia, first Green Star SA-Namibia Office Rated building • Nobelia Office Tower, Rwanda, first 6 Star Green Star SA-Rwanda Office Rated building outside of South Africa, and first in Rwanda • Menlyn Maine Central Square, first Green Star Custom Tool Rated building in South Africa • WSP House, first Green Star Existing Building Performance Rated building in South Africa • Received the Established Green Star Accolade at the 2015 Green Star Leadership Awards Contact: Alison Groves P.O. Box 9887, Sloane Park, 2152 Tel: +27 (0)11 300 6171 Email: AlisonGroves@wspgroup.co.za THE GREEN BUILDING HANDBOOK

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A Sultry Afternoon in a Naturally Ventilated Office During the hottest summer on record

Dr Dirk Conradie

Image by Solid Green Consulting


2

Introduction

This article is about the experience of discomfort, applicable physics and some possible corrective actions in a very hot naturally ventilated office on the CSIR campus during the hottest summer in Pretoria on record, as reported by South African Weather Service. Although this particular office has a split unit air conditioner the author, being a great believer in passive design, never uses it. Conventional design wisdom argues that a high thermal mass building is the answer in climates that have a high diurnal temperature swing such as South Africa due to the so called “fly wheel” effect. Thermal mass is the ability of a material to absorb and store heat energy. A large amount of heat energy is required to change the temperature of high density materials like concrete, bricks and tiles. They are therefore said to have high thermal mass. Lightweight materials such as a light weight steel construction have low thermal mass (Reardon et al., 2013). Appropriate use of thermal mass throughout a building can make a big difference to comfort and heating and cooling operational costs. The author’s office is the most massive simple structure that was immediately available for analysis. Traditionally most buildings have been built using masonry in South Africa. This case study quantifies the discomfort in a typical high thermal mass office building in the CSIR in Pretoria (the author’s office) during the extreme heat wave experienced in December 2015 and January 2016, when dry bulb temperatures reached 42.5 °C as measured by the author’s own WH3081 solar wireless weather station made by Fine Offset. This weather station consists of base station (console) and a suite of outdoor sensors that transmits the various readings to the base station. The previous summers of December 2014 and January 2015 were also extremely hot. The article critically analyses the effect on comfort and passive methods that could have made it more comfortable. It also investigates the limits to

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passive methods under these rather extreme conditions.

Background

Figure 1: Office A334, the author’s office at the CSIR.

The author’s office is a north facing office and has a total surface area of 78.720 m². The floor area is 15.360 m² and the volume is 46.080 m³. The window area is 3.439 m², i.e. 22.4% of floor area. The openable window area consists of 3 x 0.92 m x 0.41 m side hung casements and 3 x 0.85 m x 0.21 m hopper windows. The total openable area is a total of 1.668 m² or 48.5% of the total window area (Figure 1). The significant effect of the high thermal mass environment and the amount of heat stored in the massive roof slab of Office A334 during the heatwave of December 2014/ January 2015 is illustrated by the office dry bulb air temperatures that were recorded by the weather station mentioned above some time ago on the morning of 13 January 2015. At arrival at 07h50 the office internal temperature was already 29.4 °C and the outside temperature only 23.8 °C with a low airspeed of 0.7 m/s. All windows were opened to ventilate the space well in an attempt to flush the hot air. The author waited 40 minutes and measured the temperatures again. At this stage the inside temperature stabilized and was the same as the outside temperature. At 08h30 both the inside and outside temperatures were 26.8 °C with a 1 m/s airspeed. The inside Relative Humidity (RH) was 52% and the outside RH 50%. During the 40 minute period the airspeed varied between

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2

Humidity (RH) was 52% and the outside RH 50%. During the 40 minute period the airspeed varied between 0.7 and 1 m/s and all windows were open. This is an indication of how difficult it is to remove heat that accumulated over a number of days in the uninsulated massive reinforced concrete slab of 225 mm thickness.

3.0 The expected effect of climate change in Pretoria

0.7 and 1 m/s and all windows were open. This is an indication of how difficult it is to remove heat that accumulated over a number of days in the uninsulated massive reinforced concrete slab of 225 mm thickness. The expected effect of climate change in Pretoria Currently the CSIR has a relatively mild Cwa (Temperate, Dry Winter, Hot Summer) KöppenGeiger climatic classification (Conradie et al., 2015). The location of the study is latitude of 25° 44’ 55.85” S and longitude of 28° 16’ 39.57” E. There are different researched opinions what the effect of climate change will be in South Africa, because it is a very complex subject. Below two recent quantitative climate predictions are discussed that give different perspectives. In the first study Rubel et al. (2010: 135-141) undertook a comprehensive study in 2010 to map the world climate change. Two global sets of climatic observations were used to determine the Köppen-Geiger climatic regions. Both sets were available in a 0.5 degree latitude/ longitude with a monthly timeline resolution. The first dataset was provided by the Climatic Research Unit (CRU) of the University of East Anglia. This dataset has nine climatological variables of which only temperature was used. This set is known as the CRU TS 2.1 and has worldwide coverage with the exception of Antartica. The second dataset was provided by the Global Precipitation Climatology Centre (GPCC) of the German weather service. This is known as the GPCC Full Data Reanalysis Version 4 for 1901-2007. This dataset covers all landareas with the exception of Greenland and Antartica. Global temperature and rainfall projections for the period 2003-2100 of the Tyndall Centre for Climate Change Research dataset (TYN SC 2.03) was also used. This consists of a total of 20 Global Climate Change simulations, combined with four possible future IPCC Special Report Emissions Scenarios (SRES) (IPCC, 2000: 3-5). The

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Currently the CSIR has a relatively mild Cwa (Temperate, Dry Winter, Hot Summer) Köppen-Geiger climatic classification (Conradie et al., 2015). The location of the study is latitude of 25° 44’ 55.85” S and longitude of 28° 16’ 39.57” E. There are different researched opinions what the effect of climate change will be in South Africa, because it is a very complex subject. Below two recent quantitative climate predictions are discussed that give different perspectives.

TYN SC 2.03 dataset takes account of the A1FI, A2, B1 and B2 scenarios. In the first study Rubel et al. (2010: 135-141) undertook a comprehensive study in 2010 to map the world climate change. Two global sets of climatic observations were used to determine the KöppenGeiger climatic regions. Both sets were available in a 0.5 degree latitude/ longitude with a monthly timeline resolution. The first dataset was provided by the Climatic Research Unit (CRU) of the University of East Anglia. This dataset has nine climatological variables of which only temperature was used. This set is known as the CRU TS 2.1 and has worldwide coverage with the exception of Antartica. The second dataset was provided by the Global Precipitation Climatology Centre (GPCC) of the German weather service. This is known as the GPCC Full Data Reanalysis Version 4 for 19012007. This dataset covers all landareas with the exception of Greenland and Antartica.

Table 1: Global Climate Change model simulations used in the two climate change simulations Global temperature and rainfall projections for the period 2003-2100 of the Tyndall Centre for Climate Change Research dataset (TYN SC 2.03) was also used. This consists of a total of 20 Global Climate Change simulations, combined with four possible future IPCC Special Report Emissions Scenarios (SRES) (IPCC, 2000: 3-5). The TYN SC 2.03 dataset takes account of the A1FI, A2, B1 and B2 scenarios.

Table 1: Global Climate Change model simulations used in the two climate change simulations Rubel et al. Engelbrecht et al. Description (2010: 138) (2016: 249) Hadley Centre Coupled Model Version 3 National Center for Atmospheric Research-Parallel Climate Model Generation Coupled Global Climate Model Second Australian Industrial Research Organization – Climate Model Version 2 Industrial Research Organization – Climate Model Australian Version 3.5Centre Model Hamburg Version 4 European National Oceanic and Atmospheric Administration National Oceanic and Atmospheric Administration German Ocean Model Japanese Agency for Marine-Earth Science and Technology

HadCM3 NCAR-PCM CGCM2 CSIRO2 ECHam4

HadCM3

CSIRO3.5 GFDL-CM2.0 GFDL-CM2.1 ECHAM5/MPI MIROC3.2-medres

The result of these simulations with regards the IPCC A1FI and B1 simulations over the period 1976-2000 up to 2076-2100 was as follows. The most visible climate change was in the northern hemishpere in the 30 – 80° band. The A1FI and B1 scenarios are the extremes, but illustrate the point quite clearly. In the period 1976-2000 29.14% of the global land area has a Köppen-Geiger of B, followed by 21.62% D climates, 19.42% A climates, 15.15% E climates and 14.67% C climates. In the A1FI scenario for the period 2076-2100 the ensemble average (Table 1) predicts that the A climates will be 22.46%, B climates 31.82%, C climates 15.2%, E climates 11.04% and D climates 19.48%. The B1 emission scenario indicates much smaller changes. In the B1 scenario for the period 2076-2100 the ensemble average (Table 1) predicts that A climates will be 21.69%, B climates 30.07%, C climates 14.29%, D climates 21.75% and E climates 12.21%. In the second study Engelbrecht et al. (2016: 247-261) used an alternative set of Global Climate Change Models (Table 1). These simulations were specifically done for South Africa and once again Köppen-Geiger maps were used to map the climate change. In all cases the A2 scenario of the IPCC has been used. According to current research by Engelbrecht et al. (2016: 247) the A2 scenario is the closest to reality for Southern Africa. A2 is almost as bad as the worst case A1FI climate change scenario. In this study the approach was different than the first study described


2

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above. The researchers took 1 to 3 °C as global and non-conscious and muscular metabolism, temperature markers and then calculated the whilst carrying out work, which is consciously local effect on South Africa that is significantly controllable, except in shivering (Auliciems higher than the average global trend. The et al., 2007). The heat produced must be majority of these similations indicate that dissipated to the environment or a change South Africa will in general have a much drier in body temperature will occur. The deep and significantly hotter future. It is clear that the body temperature is about 37 °C and the skin hot dessert zone (BWh) will expand significantly temperature can vary between 31 and 34 °C The result of these simulations with regards the IPCC A1FI and B1 simulations over the period 1976southwards andwasto a lesser extent eastwards. 2000 up to 2076-2100 as follows. The most visible climate change was in theunder northern comfort conditions. There is a continuous hemishpere in the 30 - 80° band. Simulations also indicate that a drastic local transport of heat from the deep tissues to the The A1FI and B1 scenarios are the extremes, but illustrate the point quite clearly. In the period 1976temperature increase tofollowed 6 °Cby 21.62% skin surface from where it is dissipated by 2000 29.14% of the global land area of has abetween Köppen-Geiger 4 of B, D climates, 19.42% A climates, 15.15% E climates and 14.67% C climates. In the A1FI scenario for the period can be expected locally in 1)the case of Athe 3 °C radiation, 2076-2100 the ensemble average (Table predicts that the climates will be 22.46%, B climatesconvection or (possibly) conduction 31.82%, C climates 15.2%, E climates 11.04% and D climates 19.48%. global scenario. and evaporation. The B1 emission scenario indicates much smaller changes. In the B1 scenario for the period 2076The conclusion can be made that the CSIR The body’s heat balance can be expressed as: 2100 the ensemble average (Table 1) predicts that A climates will be 21.69%, B climates 30.07%, C climates 14.29%, D climates 21.75% and E climates 12.21%. Μ ± R ± Cv ± Cd – E = ∆S simulated site in Pretoria is very likely to change In the the secondcurrent study Engelbrecht etto al. (2016: 247-261) used an alternative set ofWhere: Global Climate from Cwa a BSh Köppen-Geiger Change Models (Table 1). These simulations were specifically done for South Africa and once again Köppen-Geiger mapsboth were used map the climate cases 3 the A2 scenario Μ of the IPCC is the metabolic rate classification, intothe case ofchange. the In2alland has been used. According to current research by Engelbrecht et al. (2016: 247) the A2 scenario is the The result of these regards IPCC A1FI and theA1FI periodclimate 1976- change to reality forsimulations Southernwith Africa. A2the is almost as The badB1 assimulations the worstover case R is net radiation °Cclosest global temperature increases. latter is a 2000 up to follows. The most visible climate change in the northern above. The scenario. In 2076-2100 this studywas theas approach was different than the first was study described hemishpere in the 30 - 80° band. researchers took 1 to 3 °C as global temperature markers and thentype. calculated theElocal effect on is evaporation heat loss Köppen-Geiger Arid, Steppe, Hot climate South Africa is significantly than average global trend. The majority of these similations The A1FI andthat B1 scenarios are thehigher extremes, butthe illustrate the point quite clearly. In the period 19762000 29.14% of the Africa global land has a Köppen-Geiger B, followed by 21.62% D hotter climates, indicate that South will area in general have a muchofdrier and significantly future. It is clearis convection Cv 19.42% A climates, E climates 14.67% C climates. In the A1FI scenario forathe periodextent that the hot dessert15.15% zone (BWh) willand expand significantly southwards and to lesser 2076-2100 the ensemble average (Table 1) predicts that the A climates will be 22.46%, B climates eastwards. also indicate year that a drastic local temperature increase of between Cd 4 to 6 °Cis conduction Table 2:C Simulations The expected the global 31.82%, climates 15.2%, E climates 11.04% and when D climates 19.48%. can be expected locally in the case of the 3 °C global scenario. The B1 emission scenario indicates much smaller changes. In the above B1 scenario for the period 2076∆S C is the change in heat stored temperature will reach 1, 2 and 3 °C the 2100 the ensemble (Table predicts that A climatessite will be 21.69%, Bisclimates 30.07%, The conclusion canaverage be made that1)the CSIR simulated in Pretoria very likely to change from the climates 14.29%, D climates 21.75% and Eclassification, climates 12.21%. current Cwa to a BSh Köppen-Geiger both in theClimate case of the 2 andIf 3 °C current baseline for different Global ∆Sglobal is positive, the body’s heat temperature temperature increases. The latter is a Köppen-Geiger Arid, Steppe, Hot climate type. In the second study Engelbrecht et al. (2016: 247-261) used an alternative set of Global Climate increases, if negative, it decreases. In warm Change Models. Change Models (Table 1). These simulations were specifically done for South Africa and once again Table 2: The expected year when thethe global temperature reach 1, scenario 2 and 3of°Ctheabove Köppen-Geiger maps were used to map climate change. In allwill cases the A2 IPCC the current has been According to current research by Engelbrecht is the baseline forused. different Global Climate Change Models. et al. (2016: 247) the A2 scenario conditions the body responds by vasodilation, closest to reality for Southern Africa. A2 is almost as bad as the worst case A1FI climate change scenario. In this study the approach was different than the first study described above. The Engelbrecht et al. (2016: 249) 1 °C 2 °C 3 °C subcutaneous blood vessels expand and researchers took 1 to 3 °C as global temperature markers and then calculated the local effecti.e. on South Africa that is significantly higher than the average global trend. The majority of these similations HadCM3 2032a much drier 2058 2079hotter future. It is increase indicate that South Africa will in general have and significantly clear the skin blood supply and therefore CSIRO3.5 2021 2071 that the hot dessert zone (BWh) will expand significantly2051 southwards and to a lesser extent eastwards. Simulations also indicate that2029 a drastic local temperature increase 6 °C GFDL-CM2.0 2058 2078 of between 4 tothe skin temperature. This in turn increases can be expected locally in the case of the 3 °C global scenario. GFDL-CM2.1 2026 2064 2083 ECHAM5/MPI 2037 2061 2077 heat The conclusion can be made that the CSIR simulated site in Pretoria is very likely to change from the dissipation. If this cannot restore thermal MIROC3.2-medres 2019 2054 2070 current Cwa to a BSh Köppen-Geiger classification, both in the case of the 2 and 3 °C global temperature increases. The latter is a Köppen-Geiger Arid, Steppe, Hot climate type. equilibrium, the sweat glands are activated Table 3: The percentage area of the different Köppen-Geiger climate types in Southern Africa in Table 2: The expected year when the global temperature will reach 1, 2 and 3 °C above the current comparison to the historic basis (1961-1990) (Processed from Engelbrecht et al.,and 2016: 251 results. evaporative cooling will operate. Sweat Table The percentage area of the different baseline for3: different Global Climate Change Models. Köppen-Geiger climate Current 3 °C can be produced for short periods at a rate Engelbrecht et al. (2016: 249) 1 °Ctypes2 °C 3 °C 2 °C Africa Köppen-Geiger climate in1 °C Southern family basis 1.74 2.16 2.89 3.96 inABcomparison to the historic basis (1961-1990) of four L/h. The sustainable rate is about one 77.58 78.93 82.57 82.65 C 20.67 18.91 14.55 13.39 (Processed from Engelbrecht et al., 2016: 251 L/h. Evaporation is an endothermic process. It result heat at the rate of approximately 2.4 4.0 Heat exchange processes in the body and its effectabsorbs on comfort Table 3: The percentage area of the different Köppen-Geiger climate types in Southern Africa in MJ/L (= 666 Wh/L). comparison to the historic basis (1961-1990) (Processed from Engelbrecht et al., 2016: 251 results. The human body continuously produces heat. This metabolic heat production is of two kinds, i.e. Köppen-Geiger Current processes which are continuous and non-conscious and muscular basal metabolismclimate due to biological 1 °C 2 °C 3 °C When these mechanisms cannot restore family basis metabolism, whilst carrying out work, which is consciously controllable, except in shivering (Auliciems et al., 2007). The heat produced must be dissipated to the environment or a change in body balance conditions, inevitable body heating temperature will occur. The deep body temperature is about 37 °C and the skin temperature can vary between 31 and 34 °C under comfort conditions. There is a continuous transport or of heat from the hyperthermia will occur. When deep 4.0 Heat exchange processes in the body and its effect on comfort body temperature reaches about 40 The human body continuously produces heat. This metabolic heat production is of two kinds, i.e. basal exchange metabolism due to biological processes whichin are continuous and non-conscious and muscular °C, heat stroke may develop. This is a Heat processes the body metabolism, whilst carrying out work, which is consciously controllable, except in shivering (Auliciems et al., 2007). The heat produced must be dissipated to the environment or a change in body circulatory failure, venous return to the and its effect on comfort temperature will occur. The deep body temperature is about 37 °C and the skin temperature can vary between 31 and 34 °C under comfort conditions. There is a continuous transport of heat from the The human body continuously produces heart is reduced that leads to fainting. At heat. This metabolic heat production is heat stroke the temperature rapidly rises of two kinds, i.e. basal metabolism due to to over 41 °C, sweating stops, coma sets biological processes which are continuous in and death is imminent. Even if a person HadCM3 CSIRO3.5 GFDL-CM2.0 GFDL-CM2.1 ECHAM5/MPI MIROC3.2-medres

A B C

2032 2021 2029 2026 2037 2019

1.74 77.58 20.67

2058 2051 2058 2064 2061 2054

2.16 78.93 18.91

2079 2071 2078 2083 2077 2070

2.89 82.57 14.55

3.96 82.65 13.39

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2 is saved at this point, the brain may have suffered irreparable damage. At about 42 °C death would probably occur. The six principal factors that contribute to the sensation of thermal comfort are (Auliciems et al., 2007, p. 8; ASHRAE, 2004, p. 4; van Reenen, 2014, p. 42): • Air temperature (Dry bulb, 18 to 26 °C) • Radiant temperature • Humidity (25 to 60% RH) • Air movement (< 2 m/s) • Metabolic rate (activity measured in met) • Clothing levels/ insulation (clo) To this can be added some other contributing factors such as: • Food and drink • Acclimatization • Body shape • Subcutaneous fat • Age and gender • State of health Air temperature is the most important environmental factor, measured by the dry bulb (DBT ). This determines the convective heat dissipation, together with air movement. In the presence of air movement the surface resistance of the body and clothing is much reduced. During the heat wave a maximum temperature of 42.5 °C was reached in Office A334. Air movement is measured by its velocity in m/s. It affects the evaporation of moisture from the skin or evaporative cooling effect. Due to the topography of Pretoria, being between two parallel ranges of mountains and hills, it is generally very wind still and therefore natural evaporative cooling Humidity in the air also affects evaporation rate. This is expressed as the RH%, absolute humidity or moisture content, AH (g/kg) and vapour pressure p in kPa. During the heat wave the RH was fortunately still mostly within the 25% to 60% range. In the simulations and synthetic weather file

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created the RH range between 26% and 70% RH, whereas the dry bulb temperature range from 23.2 °C to 38.4 °C on the hottest day used in the simulations. Radiation exchange will depend on the mean temperature of the surrounding surfaces, weighted by the solid angle subtended by each surface. This is referred to as the mean radiant temperature (MRT ). During the heatwave this played a significant role, especially the radiant heat from the hot reinforced concrete roof slab above. This aspect wasn’t measured. Standard Effective Temperature (SET) and New Effective Temperature (ET*) and its relationship to bioclimatic design Victor Olgyay initiated the concept of bioclimatic design in 1963 (Olgyay, 1963). He was a leading researcher in the investigation on the relation between architecture and energy. Other researchers such as Givoni developed the concept further by changing the original square bioclimatic chart to overlays on a regular psychrometric chart (Givoni, 1969). Watson et al. (1993) refined the principles further (Figure 3). The work of the bioclimatic researchers and Gonzalez (Gonzalez et al., 1974) indicated that Standard E ffec tive Temperature (SET ) is a very good heat strain index or indication of human comfort. SET is closely related to the New Effective Temperature (ET*) that has been used in the Watson and Labs climate strategies (Figure 3). ET* has been developed using the two-node model. The two-node model is a model that first treats the heat transfer from the body core to the skin, then from the skin to the environment (Auliciems et al., 2007, p. 16). It is defined as the dry bulb temperature (DBT) of a uniform enclosure at 50% relative humidity, which would produce the same net heat exchange by radiation, convection

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2

and evaporation as the environment in question. E T* lines coincide with DBT values at the 50% RH cur ve on the psychrometric char t. Radiation is taken into account by using operative temperature (OT ) on the horizontal scale instead of DBT (Auliciems et al., 2007, p. 36). Clothing is one of the dominant factors affecting heat dissipation. For the purposes of thermal comfort studies a unit has been devised called the clo. This corresponds to an insulating cover over the whole body of a transmittance (U-value) of 6.45 W/m².K or a resistance of 0.155 m²K/W (Auliciems et al., 2007, p. 9). SET is a sub-set of ET* under standardised conditions in terms of metabolic rate and clothing. It was established that an inverse change of clo can compensate for an increase of met. Equivalence pairs of metabolic rate and clo was suggested that would give the same SET value (Auliciems et al., 2007, p. 39).

weather files use the IPCC report of 2007 (Meehl et al., 2007). The averages of all 18 models have been included in software. Three different scenarios B1 (low), A1B (mid) and A2 (high) are available. The anomalies of temperature, precipitation, global radiation of the periods 2011–2030, 2046–2065, 2080–2099 were used for the calculation of future time periods. The forecast changes of global radiation until 2100 with all scenarios are relatively small compared to temperature changes.

Bioclimatic analysis for Pretoria (CSIR campus) A s i n d i c a t e d a b o v e t h e c u r re n t expectations are that South Africa will have an A2 climate change scenario. To quantify the effect of climate and to simulate the effect of a heat wave, the weather file creation software Meteonorm was used to create various weather files. The first one is as close as possible to the current climate, i.e. with a period of radiation from 1991 to 2010 and the period for temperature 2000 to 2009. Three other weather files were also created using an A2 climate change scenario for 2020, 2030 and 2100. These were used to investigate the expected change in degree days with climate change for the location under consideration. The M eteonor m climate change calculations to create future synthetic

Figure 2: General possible strategies that could be used for climate control.

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Figure 2 illustrates basic passive strategies that can be used to control the climate in a building. This is further explained in Figure 3 below and finally quantified with the calculations that were used to produce Figure 4.


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Figure 3: Strategies of climate control overlaid on a psychrometric chart (After Watson and Labs).

Table 4: Recommended passive design Climate Consultant 6.0 Beta was used to create the bioclimatic analysis illustrated in Figure 4 using strategies, currently and with climate the general principles illustrated in Figures 2 and 3. These quantify the shifts in strategies with climate change. Table 4 details the number of annual hours that particular passive design strategies would change wave) have a benefit as(heat well as the expected change in these values with climate change. Figure 4: Climate Consultant used to investigate change in design strategies. The diagram left is the current situation and the diagram on the right with an A2 climate change by the year 2100.

Table 4: Recommended passive design strategies, currently and with climate change (heat wave)

Figure 3 illustrates the general principles of the passive strategies that should be applied, depending on where the dr y bulb temperature/ relative humidity hourly combinations fall into different areas on the psychrometric chart. During the heatwave these combinations fell mostly in zones 14B, 16 and 17. This indicates that evaporative cooling was still feasible, but that the limit of what is achievable with passive methods has probably been reached.

Recommended Passive Design Strategy

Strategy Sun Shading of Windows High Thermal mass Internal Heat gain Passive Solar Direct Gain High Mass Dehumidification only Cooling, add dehumidification if needed Heating, add Humidification if needed.

Current situation (hours)

Climate Change to 1 2100 (hours)

1 209 620 3454 2310 655 93 842

1 384 716 3199 2183 863 264 742

Analysis of internal temperatures and effect on comfort in a typical north facing CSIR office during a heat wave 1

An A2 climate change scenario has been assumed with the calculation.

Figure 5: Plan and typical section of building used in detailed simulations

Figure 4: Climate Consultant used to investigate change in design strategies. The diagram left is the current situation and the diagram on the right with an A2 climate change by the year 2100.

Climate Consultant 6.0 Beta was used to c re a te t h e b i o c l i m a t i c a n a l y s i s illustrated in Figure 4 using the general principles illustrated in Figures 2 and 3. These quantify the shifts in strategies with climate change. Table 4 details the number of annual hours that particular passive design strategies would have a benefit as well as the expected change in these values with climate change.

A slightly simplified baseline simulation model based on Figure 5 was created in Ecotect (Figure 6) to test the effect of various possible interventions to improve the thermal comfor t in essentially a passive environment during a heatwave or the effect of global warming. The author’s office is A334. To ensure a more reliable simulation a more typical location in the middle of the simulation model office A332, the one marked with red, was used (Figure 6). This office is identical to the author’s office. It is north facing and has a total surface area of 78.720 m². The floor area is 15.360 m² and the volume is 46.080 m³. The window area is 3.439 m², i.e. 22.4% of floor area. The openable area consists of 3 x 0.92 m x 0.41 m side

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hung casements and 3 x 0.85 m x 0.21 m hopper windows. The total openable area is a total of 1.668 m² or 48.5% of the total window area. Table 5 lists all the detailed material specifications of this high thermal mass environment. The same definitions were used in the six simulations discussed below.

reached. The maximum variation was 9.2 °C. • With the Low-e glass a minimum of 30.3 °C and a maximum of 34.9 °C were reached. The maximum variation was 7.4 °C. • The cool roof was a little bit better with a minimum of 29.0 °C and a maximum of 33.2 °C. The maximum variation in this case was 6.1 °C. • In the case of insulation combined with Low-e glass the minimum was 29.6 °C and a maximum of 32.2 °C. The maximum variation was 6.8 °C. • In the last case using just roof insulation the minimum temperature was 29.2 °C and a maximum of 32.4 °C. The variation was 6.3 °C. From the analysis it appears that the 100 mm roof insulation and cool roof interventions are the most beneficial. Although the insulation only case is a little bit hotter from 10h00 to 15h00 in comparison to the insulation and low-e combination, the latter is slightly worse in the late afternoon

Figure 6: Ecotect simulation model used to simulate temperature during a heatwave.

Table 5: Materials used in the thermal simulation of the model in Figure 6.

Six simulations were run, using a synthetically created climate change one for year 2100, using an A2 climate change scenario to have enough global warming to match the heat wave experienced in the office as closely as possible. The simulations were for the existing office (baseline) followed by the following various possible inter ventions: low-e glass; cool roof; roof insulation combined with low-e glass; and finally with just roof insulation. The results are graphed in Figure 7. The following results were obtained: • In the case of the baseline a minimum of 32.4 °C and maximum of 36.2 °C were

Materials used during simulation

Material

Material Description (layers)

U-value W/m².K

Admittance W/m².K

Exterior wall (cavity wall)

1. 110 mm brick 2. 90 mm air gap 3. 110 mm brick 4. 10 mm plaster

1.780

4.590

Interior wall

1. 10 mm plaster 2. 110 mm brick 3. 10 mm plaster

2.620

Floor slab

1. 225 mm reinforced concrete

Roof slab (baseline) Roof slab with insulation

Solar Time lag Absorption (hours) [0,1] 0.559

7.8

4.380

0.418

3

3.000

5.200

0.322353

4

1. 225 mm reinforced concrete

3.000

5.200

0.753

4

1. 100 mm polystyrene 2. 225 mm reinforced concrete

0.350

5.230

0.322353

4

Roof slab (white roof)

1. 225 mm reinforced concrete

3.000

5.200

0.322353

4

Window 4 mm clear glass

1. 4 mm clear glass

6.000

6.000

0.94

2

-

Window double glazed, low e

1. 6 mm glass 2. 30 mm air gap 3. 6 mm low-e glass

2.410

2.380

0.75

3

-

Doors

1. 40 mm solid core door

2.310

3.540

0.404

Door light (above door)

1. 4 mm clear glass

6.000

6.000

0.94

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0.4 -

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NATURAL VENTILATION

2

Figure 7: Temperature in office A332 on the hottest day with different materials and combinations (Author)

Solar Penetration A general rule of thumb is to make the overhang size such that the angle from the centre of the window sill through the edge of the overhang the same as the solar noon angle at the equinoxes for the given latitude (equinox latitude approach). SANS 204 (2011, pp.15-17) also describes a basic method to calculate the shading of the northern faรงade. It states that it should be capable of restricting at least 80% of summer solar radiation and if adjustable is readily operated either manually, mechanically or electronically by the building occupants. In all cases the general idea of this is to exclude the sun during the hot months and include it during the colder seasons. It is also important to realize that the seasons do not follow the geometrical solar positions such as the summer and winter solstices exactly. Although the winter solstice is on 21 June, the coldest period is normally later in July and even August. Similarly the hottest period in summer is not necessarily on summer solstice (21 December), but quite often only in January and February. It is clear from above that the hotter the climate gets with heat waves and climate change the more important adequate shading becomes to avoid unnecessary heat gains especially from the roof that is a very large exposed area and also the windows. To determine the ideal amount of northern overhang Climate Consultant 6.0 Beta software

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THE GREEN BUILDING HANDBOOK

was used to calculate the best northern overhang angles for the current situation and with climate change, using actual weather files. The same weather files that were used for the temperature simulations in Figure 7 were used in this analysis. In terms of this article climate change is really a more continuous heatwave and not just the particular hot day that was investigated. Figure 8 illustrates the Climate Consultant screens when the analysis was undertaken. Table 6 quantifies the different types of solar exposure in hours. To define the desired overhang Climate Consultant provides a circle that can be dragged vertically in the solar exposure diagram (Figure 8). By carefully observing the real time calculated hourly values for warm/ hot, comfortable and cool/ cold the user can determine the ideal balance between solar exposure and shading. This is the main factor that determines the ideal overhang size. This also takes account of the seasonal lag discussed above. The calculated angle is measured from the centre of the window sill. The overhang should be such that an imaginary line from the centre of the sill touches the edge of the overhang at the correct angle measured from the northern horizon. In this case study these critical solar angles were determined by means of Climate Consultant and the corresponding overhang sizes were calculated with the simple formulas 2 to 7.

Figure 8: The figure on the left shows the current climatic situation. The figure on the right shows the estimated climate change situation by 2100.


2

NATURAL VENTILATION

the overhang at the correct angle measured from the northern horizon. In this case study these critical

installations in South Africa. There are slight differences with the values used in the building performance model (Table 5). It is clear that glass is by far the weakest link in building design. For a full discussion of glass please refer (6) y = 1264 × 1.0 toy =a1264 previous (Conradie et al.,(7) 2015, Figure 8: The figure on the left shows the current climatic situation. The figure onchapter. the right shows the estimated change situation by 2100. During theto analysis it became clear that the current solar Table 6: climate Estimated altitude angles pp.112-121) Where: Window height is 1 264 mm be an altitude of 55° angle at noon used for the calculation of the shading device (overhang) should 45° is the complimentary angle of 45° calculate overhang sizes. Calculated by now and for climate change reduced to 45° above the northern horizon.. Figure 8: The figure on the left shows the current climatic situation. The figurewindow on the rightconfigurations shows the 7.2 Glass Climate Consultant (Author) Table 7: Typical estimated climate change situation by 2100. During theTable analysis it became clear that the current solar 7 below has been included to illustrate the performance of typical glass and window Table 6: Estimated altitude angles to calculate overhang sizes. Calculated by Climate Consultant by means ofbethe U-Solve3 software installations (overhang) in South Africa. There are slight differences with the values used of in the55° building angle at noon used for the calculation of the shadinggenerated device should an altitude (Author) performance model (Table 5). It is clear that glass is by far the weakest link in building design. For a now and for climate change reduced to 45° above the northern horizon.. full discussion of glass please refer to a previous chapter. (Conradie et al., 2015, pp.112-121) (Author) Recommended overhang size, now and for climate change solar angles were determined by means of Climate Consultant and the corresponding overhang sizes During the analysis it 2became clear that the current were calculated with the simple formulas to 7. solar angle at noon used for the calculation of the shading device (overhang) should be an altitude of 55° now and for climate change reduced to 45° above the northern horizon..

Figure 8: The figure on the left shows the current climatic situation. The figure on the right shows the estimated climate change situation by 2100. During the analysis it became clear that the current solar angle at noon used for the calculation of the shading device (overhang) should be an altitude of 55° now and for climate change reduced to 45° above the northern horizon..

Table 6: Estimated altitude angles to calculate overhang sizes. Calculated by Climate Consultant (Author) Recommended overhang size, now and for climate change Current climate Climate change 55° altitude 45° altitude Warm/ hot > 27 °C (Shade needed):

Exposed (hours) Shaded (hours)

12 438

73 1155

Table 7: Typical window configurations generated by means of the U-Solve3 software (Author)

Current climate Climate Table 6: Estimated altitude angles to calculate overhang Calculated bychange Climate Consultant No. sizes. Type of Glass Frame U-value U-Value Exposed (hours) 289 381 whole Centre of 55° altitude 45° altitude window (Author) Shaded (hours) 913 593 Glass (W/m² (W/m² K) K) Warm/ hot > 27 °C (Shade needed): Exposed (hours) 12 for climate change 73 Cool/ Cold < 20 °C (Sun needed): Exposed (hours) 651 301 Recommended overhang size, now and Shaded (hours) 249 49 Shaded (hours) 115538 1 438 PFG Clearvue 4 mm Casement Current climate Climate 6.14 change 5.879 2 PFG Intruderprufe 6.38 mm Casement 38 6.01 5.749 In terms of the actual case study the overhangs can be calculated as follows below. Assume that the Inwindowterms ofThe current theconcrete actual case study 3 PFG 20 mm Clearvue Casement 38 3.77 2.729 height is 1264 mm. overhang projects outward from the top of the the 55° altitude 45° altitude Comfortable > 20 °C (Shade helps):

SHGC

0.661 0.637 0.580

Comfortable > 20 °C (Shade helps): Exposed (hours) 289 381 Warm/ hot > 27be °C (Shade needed): as follows Exposed (hours) 12 73 overhangs can calculated Shaded (hours) 593 Shaded (hours)913 438 1155 y = tan( 35)Assume that the window height is below. 1264 Cool/ Cold < 20 °C (Sun (hours) 301 > 20needed): °C (Shade helps):Exposed Exposed (hours)651 289 381 1264 The current concrete overhang y = 1264 ×mm. 0Comfortable .7 Shaded (hours) 49 y = 885 Shaded (hours)249 913 593 projects outward from the top of the In terms of the actual case study the overhangs can be calculated as follows below. Assume that the window. Cool/ Cold < 20 °C (Sun needed): Exposed (hours) 651 301 window height is 1264 mm. The current concrete overhang projects outward249 from the top of the 49 Shaded (hours) For a 55° altitude solar angle the ideal 8.0 Conclusions y window. = tan( 45) 1264 current in mm should be:overhangs can Conclusions conclusions can beas made from the article and some really interesting discoveries have been In overhang terms of the actual case study the beMany calculated follows below. Assume that the made. It is clear that in hot climates during heatwaves or with the expected climate change solar For a 55° altitude solar angle the ideal current overhang in mm should be: window height is 1264 mm. The current concrete overhang projects outward the top control is becoming increasingly important. Itfrom is reasoned and supported simulation that thisfrom will Many conclusions can beofbythe made mean increasing the amount of shade by increasing the overhang size on the northern façade. In y window. practice article this means keeping and the roof as cool as possible andreally using correctly sized overhangs on the the some interesting (2) = tan( 35) northern façade and appropriate solar protection on the other facades. It is important to realise that in 1264 For a 55° altitude solar angle the ideal current overhang Pretoria solar gains from the southern façade is also significant, because in summer the sun rises well mm should be: been made. It is clear that discoveries have southin of east and sets south of west. y A surprising finding is that using just good roof insulation isheatwaves to the combination of in hot climates during or with (3) a little bit superior y = 1264 × 0=.7tan( 35) (2)contributor low-e glass and insulation. This is probably due to the fact that major heat in this case is the massive roof slab and the low-e glass tends to trap the heat rather than dissipate it. The single 1264 the expected climate change solar control (4) y = 885 most effective measure is the use of a cool roof or white roof. The use of just low-e glass does not as much as expected. iscontribute becoming increasingly important. It is y = 1264 × 0.7 Improved ventilation will also help to promote evaporative cooling from(3) the skin and in the process Where: increase the general sense of comfort.supported From personal experience it isby clear thatsimulation the human body can Where: reasoned and (4) y = 885 withstand higher temperatures if it had enough time to adapt or acclimatize. Window height is 1 264 mm Window height is 1 264 mm that this will mean increasing the amount 35° is the complimentary angle of 55° Where: 35° is the complimentary angle of 55° of shade by increasing the overhang size Window height 1 264 For a 45° altitude solarisangle themm ideal future overhang in mm should be: For a 45° altitude solar angle the ideal future on the northern façade. In practice this y 35° is the complimentary angle of 55° (5) as cool as possible = tan( 45 ) overhang in mm should be: means keeping the roof 1264 For a 45° altitude solar angle the ideal future overhang in mm should be: and using correctly sized overhangs on y = tan( 45) the northern façade and(5)appropriate 1264 solar protection on the other facades. It is important to realise that in Pretoria solar (6) y = 1264 × 1.0 gains from the southern façade is also (7) y = 1264 significant, because in summer the sun rises well south of east and sets south of west. Where:Where: Window height is 1 264 mm A surprising finding is that using just Window is 1 264 angle mm of 45° 45° height is the complimentary good roof insulation is a little bit superior 45° is the complimentary angle of 45° 7.2 Glass to the combination of low-e glass and Table 7 below has been included to illustrate the performance of typical glass and window Glass installations insulation. This is probably due to the fact in South Africa. There are slight differences with the values used in the building Table 7performance below has been included tothat illustrate that majorlink heat contributor model (Table 5). It is clear glass is by far the weakest in building design. For in a this case is full discussion of glass please refer to a previous chapter. (Conradie et al., 2015, pp.112-121) the performance of typical glass and window the massive roof slab and the low-e glass window.

For a 55° altitude solar angle the ideal current overhang in mm should be:

4

(2)

5

(3)

(4)

Where: Window height is 1 264 mm 35° is the complimentary angle of 55°

6

Insulated Glass Unit (4 mm + 12 mm air gap + 4 mm) PFG 25 mm Intruderprufe Insulated Glass Unit (6.38 mm = 12 mm + 6.38 mm) PFG 20 mm Clearvue Insulated Glass Unit Low-e 94 mm + 12 mm air gap + 4 mm) PFG 25 mm Intruderprufe Insulated Glass Unit (6.38 mm = 12 mm + 6.38 mm low-e)

Casement 38

3.68

2.673

0.537

Casement 38

3.05

0.679

0.526

Casement 38

2.99

1.878

0.486

For a 45° altitude solar angle the ideal future overhang in mm should be:

(5)

Table 7: Typical window configurations generated by means of the U-Solve3 software (Author) No. Type of Glass Frame U-value U-Value SHGC whole Centre of window Glass (W/m² (W/m² K)THE GREENK)BUILDING HANDBOOK 1

PFG Clearvue 4 mm

Casement 38

6.14

5.879

0.661

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NATURAL VENTILATION

2

tends to trap the heat rather than dissipate it. The single most effective measure is the use of a cool roof or white roof. The use of just low-e glass does not contribute as much as expected. Improved ventilation will also help to promote evaporative cooling from the skin

and in the process increase the general sense of comfort. From personal experience it is clear that the human body can withstand higher temperatures if it had enough time to adapt or acclimatize

References • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

ASHRAE. 2004. Thermal Environmental Conditions for Human Occupancy. American Society of Heating, Refrigeration and Air-Conditioning Engineers, Atlanta, GA. Auliciems, A. and Szokolay, S. 2007. Thermal Comfort. In Passive and Low Energy Architecture International (PLEA) in association with Department of Architecture, The University of Queensland, Brisbane. Conradie, D.C.U. and Szewczuk, S. 2015. The use of glass in buildings – from Crystal Palace to Green Building. In Green Building Handbook for South Africa, Volume 8, pp. 112-121. Conradie, D.C.U., van Reenen, T. and Bole, S. 2015. The Creation of Cooling Degree (CDD) and Heating Degree Day (HDD) Climatic Maps for South Africa. In Proceedings of the 5th CIB international Conference on Smart and Sustainable Built Environments (SASBE), University of Pretoria, Pretoria. Engelbrecht, C.J. and Engelbrecht, F.A. 2016. Shifts in Köppen-Geiger climate zones over southern Africa in relation to key global temperature goals. In: Theoretical and Applied Climatology, Volume 123, Issue 1, pp. 247-261. Givoni, B. (1969). Man, Climate and Architecture. Elsevier Publishing Co. Ltd., New York, NY. Gonzalez, R. R., Nishi, Y. and Gagge, A.P. (1974). Experimental evaluation of standard effective temperature: a new biometeorological index of man’s thermal discomfort. In International journal of biometeorology, 18(1), 1–15. IPCC. 2000. Emission Scenarios, Summary for Policymakers: A Special Report of IPCC Working Group III. Published for the Intergovernmental Panel on Climate Change, pp. 3-5. Meehl, G.A. and Stocker, T.F. 2007. IPCC Fourth Assessment Report: Climate Change 2007. Working Group I: The Physical Science Basis. Olgyay, V. (1963). Design With Climate: Bioclimatic Approach to Architectural Regionalism. Princeton University Press. Reardon, C., McGee, C. and Milne, G. 2013. Passive design: Thermal mass. In Yourhome, Australia’s guide to environmentally sustainable homes. Australian Government. http://www.yourhome.gov.au/passive-design/thermal-mass . Accessed on 19 July 2016. Rubel, F. and Kottek, M. 2010. Observed and projected climate shifts 1901-2100 depicted by world maps of the Köppen-Geiger climate classification. In: Meteorologische Zeitschrift, Vol. 19, No. 2, pp. 135-141. SANS 204. 2011. Energy efficiency in buildings. South African National Standard, SABS Standards Division, pp. 15-17. Van Reenen, T. 2014. Indoor Enviromental Quality and Building Energy Efficiency. In The Green Building Handbook, the Essential Guide, Vol. 6., pp. 41-51. Watson, D. and Labs, K. (1993). Climatic Building Design: Energy-Efficient Building Principles and Practices. McGraw-Hill.

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Ground Floor, Block 2A Tyger Terraces 2 DJ Wood Way, Bellville, 7530 Cape Town, South Africa Tel. +27 (21) 948 1877 / 2593 Fax +27 (21) 948 3455 e-mail: info@avna.co.za www.avna.co.za

• •

g r e e n b u i l d i n g d e s i g n • e n e r g y c alc ulat i o n • gr e e n r at ing specif ication • life cycle assessment • gr een build document at ion

• •


ON THE CUTTING EDGE OF GREEN DESIGN – dirk du toit Towards the end of 2014, AVNA Architects received a request from a developer client, Devmark Property Group, to achieve an EDGE certification (Energy, Water consumption and Embodied energy rating tool) for a GAPP housing development in Cape Town. The project at stake is a combination of three and four storey Apartment Blocks with a total of 253 Apartments. The apartment unit mix is: • 50 One Bedroom apartments with a floor area of 34m2 • 203 Two Bedroom apartments with a floor area of 46m2 The project is known as The Block Glenhaven-Precinct 1 as developed by Devmark Property Group (Developer) for International Housing solutions (Investor/Purchaser). As is often the case the green certification requirement was not the brief from the outset. The purchaser/investor for the project was not known from the outset. This is common in commercially developed projects. Idealistic green building strategies and thinking assumes that all green building and energy saving interventions should be part of the design from the outset. A perimeter block design approach (for urban design and economical reasons) was adopted on this project from the outset, reducing chances for an optimal North facing orientation for each apartment. The orientation thus had to be addressed from an energy use perspective. EDGE CERTIFICATION This challenge had to be solved with combined knowledge of green design principles and using the Edge Software for the first time. With experience of other Green Rating and Energy Certification design tools, we found the Edge tool to live up to it’s claim to be “simple to use and very efficient”. As the Edge tool was not adopted by the GBCSA, we studied the IFC (International Finance Corporation) website and found the EDGE (Excellence in Design for Greater Efficiencies) on-line tool or app. Questions on which Options to select for this specific project, how to interpret some Options and the definition and explanations surrounding green interventions were answered by the local EDGE auditor and advisor. He quickly guided AVNA in the right direction in addition to the EDGE handbook that can be downloaded. EDGE OBJECTIVE The objective of this tool is to guide the building designer to make physical design interventions and choose and apply specifications in order to achieve the following results: •

A 20% saving in Energy consumption (Electricity bill) compared to a standard design by choosing interventions such as, reflective paint finishes, solar shading solutions, superior glass, low-energy lighting, efficient HVAC systems, and more.

A 20% saving in Water consumption (Water bill) compared to a standard design by choosing low-flow faucets, efficient water closets, recycled water systems and more.

A 20% saving in the Embodied Energy of the Materials used on the project compared to a standard design by choosing floor-, roof-, wall- and window construction systems with low embodied energy. (A major consideration towards saving the resources of the Planet in the long run.)

The first aim of the building designer is to obtain Preliminary (Theoretical) EDGE certification. This is achieved by choosing the appropriate interventions, under each of the three target areas, to achieve a minimum saving of 20% in each. To achieve this the program parameters are entered for evaluation, each prototype of apartment is assessed separately, and thus we opened a project for each apartment type. Two certifications or projects were created on-line for the two types of apartments.


The handbook gives clear explanations on how to enter parameters and defines the information to be entered. Figures have to be correct and accurate as these are used in all the background calculations by the Edge program. Once the project parameters are inserted, the Edge program’s interactive dashboard or interface, shows the amount or percentage savings achieved in each section. The amount and level of intervention to be chosen in each section is dependent on how effective the design was to start with. It is highly unlikely that no interventions will be required. Building plans, sections, elevations and data has to also be uploaded/provided to prove the validity of the information entered. There is a variety of interventions under each section that can be mixed and matched within limitations to reach the goal. The types and combinations of interventions chosen will depend on factors including the cost of implementation and/or the preference of the client and/or the other perceived benefits and/or the value that it adds to the project. Once agreement is reached and the interventions confirmed giving the minimum 20% savings, proof in the forms of drawings, documentation and specifications for each intervention has to be uploaded. A request can then be made, through the local EDGE auditor and advisor, for the project to be audited towards achieving the Preliminary (Theoretical) EDGE certification. The project particulars, interventions and the proof and specifications are assessed. Final feedback on matters to be clarified or adjusted is provided to the applicant to be addressed, after which a Certificate is then issued. The initial process does not take an inordinate amount of time to complete and does not constitute a full additional service, as would a Green Star Rating Certification. The Block achieved PRELIMINARY (THEORETICAL) EDGE CERTIFICATION for PRECINT 1 and AVNA Architects can safely state that once familiar with the system, it is actually fairly uncomplicated and ads value to the design and project. To achieve the official EDGE certificate, the interventions proposed, and their implementation on the completed building is audited on site and the final certificate issued. This process comes at a modest cost compared to the value of the total lifecycle savings and marketability of the project.

As with anything worthwhile the learning curve is quite steep the first time but with a reasonable knowledge base most Architects and other building professionals should be able to understand, interpret and navigate the system towards achieving the desired results. Many other systems take a lot more input and achieve the same or less effective green interventions in the building’s effectively. “EDGE encourages resource-efficient building growth by proving the business case for building green. Whether you are constructing homes or apartments, hotels or resorts, offices, retail, or health care buildings, EDGE empowers you to build sustainably. Use EDGE only at the design stage or take your building all the way through to certification.”

#HOM-1.0-17-27-051-253-D

In The Block Glenhaven’s case the whole process lead to a much greater awareness regarding matters of design for efficiency and is on-going. It becomes the norm in design thinking fairly easily. To produce a building that is energy efficient in the Gapp market segment, with the budgetary constraints involved is challenging and great effort has gone into the evaluation of the interventions, their value towards achieving the 20% savings and the related costs.

This is to certify that

Glenhaven

IHS 46 Space Unit Corner of Peter Barlow Drive & Bester Road Cape Town, 7530 South Africa

has achieved

EDGE Preliminary Certification This certificate for green buildings exemplifies design achievement in resource efficiencies in the following areas: 24% ENERGY reduction; 23% WATER reduction; and 63% MATERIALS’ embodied  energy  reduction. Prashant Kapoor IFC Principal Industry Specialist


High-Performance Green Buildings

Towards A conceptual framework LLewellyn van Wyk

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Image by Hotel Verde


3 Background and Context The construction, operation and maintenance of the built environment is a significant consumer of resources (Edwards 2002:10), many of which are not renewable (inter alia steel, aluminium, clay, cement, aggregates). It is also recognised that “current planning, design, construction, and real estate practices contribute to patterns of resource consumption that seriously jeopardize the future of the Earth’s population” (AIA 2005:1). One of the identified interventions to influence resource consumption is building performance design targets (AIA 2005:2). Kibert notes that “a unique vocabulary is emerging to describe concepts related to sustainability” including concepts such as “Factor 4 and Factor 10, ecological footprint, ecological rucksack, biomimicry, the Natural Step, eco-efficiency, ecological economics, biophilia, and the precautionary principle” (2013:7). It has been argued (Gross 1996) that building performance is not a well understood or articulated concept in the building and property industries, at least not in the same way that the performance of typical consumer goods, such as an automobile, is understood. More often than not, a description of a building will include its location, prospect and aspect, and accommodation schedule. By contrast, the description of an automobile will include, inter alia, its fuel consumption, acceleration times, maximum speed, power-to-weight ratio, and braking distances and times. It can also be argued that the absence of, or a poor understanding of, building performance results in at least two consequences: first, clients are uninformed and therefore have a low expectation of how a building should perform and second, there is no or little pressure placed on the construction industry to improve performance through innovation. Establishing the requisite performance aspects becomes critical to defining and measuring building performance. This chapter reviews relevant literature to establish what

HIGH PERFORMANCE GREEN BUILDING

will be required to develop a conceptual framework for conceptualising and measuring high-performance buildings. Defining the performance concept One of the difficulties associated with the concept of performance in general is that it is associated with so many applications. Performance is defined as the “execution (of command etc.); carrying out, doing; notable feat; performing of play, piece of music, or public exhibition; achievement under test” (Oxford Dictionary 1985). It can also be viewed as “the accomplishment of a given task measured against pre-set known standards of accuracy, completeness, cost, and speed. In a contract, performance is deemed to be the fulfilment of an obligation, in a manner that releases the performer of liabilities under the contract” (BusinessDirectory 2014). Defining the building performance concept Describing building per formance in terms of codes and standards has a long tradition (Gross 1996:2): generally codes and standards focused on public health and safety. This health and safety concept was present in Hammurabi’s Code (c. 1795 to 1750 BC) where structural performance was described in terms such as “a house should not collapse and kill anybody” (New World Encyclopedia: online). Vitruvius Pollio extended the performance expectations beyond public health and safety: in his “De architectura libri decem” (“The Ten Books of Architecture”) argued that architecture needed to acknowledge ever ything touching on the physical and intellectual life of man and his surroundings (Pollio and Warren 2005). His often quoted reference to the three elements, namely, sturdiness, usefulness, and beauty, could be used for quantitative and qualitative performance analysis. In Book II he refers to the behaviour of materials.

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3

Hartkopf, Loftness and Mill (1986:2) included resource efficiency in their performance requirements submitting that the international focus on resource efficiency has pressurized the building industry into considering more than the traditional considerations of health and safety. This resource-based view was also later supported by the American Institute of Architects (AIA 2005:1). The first definition of the performance concept in building terms was introduced in 1965 by Gèrard Blachère with the development of the Agrément system whereby experts pronounce on the fitness for purpose of a product or new process (Chemillier 2011:online). The International Council for Research and Innovation (CIB) defines performance-based building as: “Performance-based building considers the performance requirement throughout the design life of the building and its components, in terms that both the owner and the users of the building understand, and which can be objectively verified to ascertain that requirements have been met. The requirements are concerned with what a building or building component is required to do and not with prescribing how it is to be constructed” (2003:12). Hartkopf et al (1986:5) argue that the performance concept is predicated on the assumption that the primary goal of a building is to serve user needs in the broadest sense as well as the needs of the surrounding community, a sentiment which seems to be taken verbatim from Vitruvius. Hartkopf et al (1986:8) and Meacham, Bowen, Traw and Moore (2005:93) also argue that what level of performance is deemed to be ‘acceptable’ is dependent on the user and the surrounding community’s physiological, psychological, sociological and economic needs. Since this introduces ‘variability’ a desired level of performance of the whole system and its resultant demand on component parts is preferred to prescriptive specifications (Hartkopf et al 1986:8). They cite,

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as examples, the deterioration in air quality that has resulted from improved air tightness, and the unexpected level of condensation that has accompanied building envelope insulation. They argue that this is, in part, due to a “lack of transdisciplinary understanding of the impact each building performance mandate has on other performance areas” and that this has given rise to the need to understand the balance needed between all performance areas which they describe as thermal comfort, acoustic comfort, visual comfort, air quality, spatial comfort, and building integrity (1986:6). This performance concept has also been the focus of much research in more recent times, particularly within Commission W60 of the International Council for Research and Innovation in Building Construction (CIB) under the banner of Performance-Based Building Thematic Network (PeBBu). In the PeBBu report it states that “Performance Based Building, PBB, is a building market environment in which all the stakeholders involved in the various phases of the building process address the need to ensure performance-in-use of buildings as an explicit target” (2005:6). It also notes that PBB is expected to facilitate the development and implementation of innovative technologies and building systems into the market (2005:6). In the report n.64 of W60 performance-based building (PBB) is described as “the practice of thinking and working in terms of ends rather than means” (PeBBu 2005:7). The PeBBu report suggests that “an essential feature in the delineation of user needs into performance requirements is the identification of the physical factors that should serve as the performance indicators” (2005:8). It argues that the factors must be quantifiable, well understood, and preferably open to computational analysis in order to enable performance prediction during the generation of design solutions. Statistical data is needed, it argues, on relations between effects of the physical factors and health, comfort, human response, perception of


3 building performance and satisfaction. This data then has to be analysed in order to identify the thresholds of dissatisfying performance and to establish design values of satisfactory performance. It also notes that design tools and accepted assessment methods are needed in order to provide solutions that respond well to user needs, performance requirements, and performance criteria. This view is widely supported by institutions who note that “programs are being directed at developing metrics, benchmarks, validation standards and verification methods for measuring high performance and providing high-performance –based design guidance and standards to the design and engineering communities” (NIBS 2010:5) and “enable the widespread adoption of high-performance goals by developing tools and processes” (NCTC 2008:21). Lutzkendorf et al (2008:62) note that the trend is toward a broader way of looking at building performance over the ‘Whole Facility Management Cycle’, with terms such as total building performance, whole life performance, overall performance and integrated building performance demonstrating the expansion of the concept. Despite a multitude of research establishments working and studying the implementation of Performance-Based Building Design (PBBD) during the past few decades – including Foster 1972; Loeszkiewicz 1997; Foliente 1998; Foliente 2000; CRISP 2001; Fairclough 2002 – there appears still not to be a systematic application of the concept in all areas of building design, which is typically not open to innovations. Gross (1996:5) and others such as Lewis, Riley and Elmualim (2010:3) note that building performance terminology and definitions are not widely accepted, and that part of the problem lies in the different meanings people derived from the concept. Gross (1996:5) noted that for some “it is a concept of qualitative aspirations for buildings without a systematic methodology for analysis and verification” while for others “it is a concept

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which requires quantitative analysis and rigorous evaluation.” Kesik (2014:6) defines building performance as “the level of service provided by a building material, component, or system, in relation to an intended, or expected, threshold or quality.” From the literature it is clear that a sharp divide exists between those advocating a quantitative approach to high-performance and those including a qualitative approach i.e. user and/or client and/or societal needs. The high-performance building concept The High-Performance Building Council (HPBC) adopted the following definition for high-performance buildings: “Highperformance buildings, which address human, environmental, economic and total societal impact, are the result of the application of the highest level design, construction, operation and maintenance principles – a paradigm change for the built environment” (NIBS 2008:11). Sexton and Barrett (2007:143) combine definitions of high-performance building from Gibson (1982:4) and Averill (1998:18) into “the practice of thinking and working in terms of ends through the quantification of the level of performance which a building material, assembly, system, component, design factor, or construction method must satisfy in order that the building meet all the goals established by society and the client.” The US Government Public Law 110-140 December 19, 2007 “Energy Independence and Security Act of 2007” (121 Stat 1598, para. 12) on the other hand omits societal and client expectations defining high-performance building as: “High-performance building’ means a building that integrates and optimizes on a life cycle basis all major high performance attributes, including energy conservation, environment, safety, security, durability, accessibility, cost-benefit, productivity, sustainability, functionality, and operational considerations.”

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As noted on the website of the HighPerformance Building Council the Energy Policy Act of 2005 (EPACT) and the Energy Independence and Security Act of 2007 (EISA) seek to reduce building-related energy consumption and dependence on foreign energy sources. Title IX, Subtitle A, Section 914 of EPACT specifically directed the National Institute of Building Sciences to explore the potential for accelerating development of consensus-based voluntary standards to set requirements for less resource-intensive, more energy-efficient, high-performance buildings. In response to Section 914 of EPACT, the High-Performance Building Council (HPBC) was formed in April 2007. More recently resilience has also been included in the definition: “high-performance requirements that affect resiliency for buildings have come under development” through a focus on “new advanced materials and products that exhibit comprehensive high-performance attributes” (NIBS 2010:5). The consideration of building impacts on health, safety and welfare informed the establishment of the High-Performance Buildings Caucus of the U.S. Congress where opportunities to design, construct and operate high-performance buildings are considered. The Caucus seeks to protect life and property, develop novel building technologies, facilitate and enhance U.S. economic competitiveness, increase energy efficiency in the built environment, assure that buildings have minimal climate change impacts and are able to respond to changes in the environment, and support the development of private sector standards, codes and guidelines that address these concerns (HPBCCC 2015:online). Building performance aspects The CIB (2003:11) describes performancebased building (PBB) as: • The use of functional terms to describe how a building will operate rather than

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the specification of how the building is to be constructed • Focusing on the end user-requirements rather than the provider • Quantification of the le vel of performance which a building material, assembly, system, component, design factor, or construction method must satisfy in order that the building meet all the goals established by society and the client • Considering of whole-life-costs and benefits rather than acquisition costs • Avoiding over- design and underdesign by careful matching of users requirements with building functionality • Giving an incentive for providers to develop innovative materials, components, systems and designs • Documenting tests and performance criteria in a way that gives surety to clients and is enforceable • Setting performance levels in codes and standards that reflect social expectations • Having flexibility to select the most appropriate level of performance • Considering performance over a design life of the facility and its components • Defining requirements in a way that does not limit the choice of a solution Building diagnosis, Hartkopf, Loftness and Mill (1986:7) suggest, establishes the suitability of a building and its component parts to serve occupants needs in the present, the probability that the service will continue to be suitable throughout the life of the building, and the flexibility and adaptability of the building to be suitable despite changing occupancies and functions. The CIB developed a conceptual framework for PBBD, largely reflecting on the work of Gross (1996:6) which establishes the following processes:


3 • User Requirements – identify and formulate the relevant user requirements (a qualitative statement giving the user need or expectation); • Performance Requirements – transform the user requirements identified into per formance requirements (a quantitative statement giving the level of performance required to meet the user needs or expectations), • Evaluation methods – establish the tests or other information upon which judgement of compliance with the performance requirement is based (use of reliable design and evaluation tools to assess whether the proposed solutions meet the stated criteria at a satisfactory level). The need for evaluation methods and metrics is supported by a number of authors who argue that it is in this area that building science has an important contribution to make, i.e. the quantification of performance parameters (Kisek 2014:6) and development of “rigorous metrics that enable high-performance building goals to be predicted, assessed, monitored, and verified and new energy-efficient technologies, products, and practices to be developed” (NSTC 2008:16). However difficulties do arise with regard to determining user requirements since user requirements will reflect different cultures, economic capabilities and expectations, and to performance requirements, especially with regard to performance over time. The latter is specifically challenging when innovative solutions are employed since “innovation cannot draw upon history” (Gross 1996:7) in the same way that traditional prescriptive solutions can. Building performance aspects Hartkopf, Loftness and Mill (1986:6) divide the definition of what they describe as performance

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‘mandates’ into two areas. The first has to do with the integrity of the building envelope with regard to the protection of the building’s visual, mechanical and physical properties. In this area they include environmental degradation, moisture, temperature, air movement, radiation, chemical and biological attack, and environmental disasters such as earthquake, flood, and fire where the performance can range from acceptable protection to failure. The second area has to do with interior occupancy requirements (human, animal, plant, artefact, and machine) and the elemental parameters of comfort – thermal, acoustic, visual, spatial comfort, and air quality. From this they then construct a list of performance mandates. In attempting to determine what the requirements would be for a properly performing building system for permanent dwellings, Becker (2002:926) developed performance categories (with matching criteria) including structural safety (global, local, stress capacity); fire safety (detection and suppression, egress provision, smoke control, fire spread control); user health/ safety (air quality, contact safety, touch safety, walking safety, personal safety); structural serviceability (deformations, vibrations, cracks); moisture safety ( water tightness, dry internal surfaces); thermal comfort (thermal conditions, solar radiation control, energy conservation); acoustics ( acoustic conditions, privacy); dimensional flexibility (architectural design, furnishability, spatial connectivity); operational comfort (doors and windows, maintenance); and durability (chemical and electrochemical, mechanical, physical). Lutzkendorf, Speer, Szigeti, Davis, le Roux, Kato, Tsunekawa (2008:63) developed the following major performance categories (with matching criteria), which strongly reflect the sustainability-based triple bottom line approach. They included functional performance (ability to satisfy use-specific

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activities and processes); technical performance (structural, physical and other technical features and characteristics); economic performance (real estate performance, cost performance); environmental performance (impact on the environment); social per formance (health, comfort and safety); and process per formance (qualit y of the process involving planning, construction, use and facility management). Kesik (2014:2) as well as Lewis et al (2010:6) describe different pillars based on building system theor y : they argue that when adopting a building as a system approach designers need to consider the interactions between the primar y elements comprising the system which he sets out as follows: building enclosure (building envelope system); inhabitants (humans, animals, plants, etc.); building services (electrical, mechanical systems); site (landscape, ser vices, infrastructure); and external environment (weather, micro-climate). Kesik argues that it is the harmonization of these elements which are critical to well-per forming buildings. He notes t h a t a l a rg e n u m b e r o f m a te r i a l s, components, equipment, and assemblies must be properly integrated to achieve a high-per formance building. He also a rg u e s t h a t b u i l d i n g p e r fo r m a n c e related problems largely originate from the building enclosure (2014:5). Noting that structural integrity must always be attended to, he lists “four primar y physical mechanisms associated with climate and weather that dr ive the behaviour of the building as a system in terms of its role as a mediator of the indoor environment” (2014:6). These are: • H e a t f l o w – t h e c o n d u c t i v e , convective, and radiative flow of heat; • Air flow – the air flow across and within the building enclosure due to air leakage and ventilation;

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• Moisture flow – the flow of water and vapour across and within the building enclosure; and • Solar radiation – the influence of insulation on the opaque and transparent enclosure components. In this sense there is a correlation with the work of Hartkopf et al (1986) and Building Performance Professionals (2015). Kisek however constructs a building science hierarchy of performance requirements (2014:7) as depicted in Figure 1 below:

Figure 1: Building science hierarchy of performance requirements (Kisek 2014:7).

With regard to developing a framework he notes (2014:7) that the concept of a building performance framework is intended to explicitly represent: • External and internal conditions affecting a building system (e.g., climate, weather, site, soils, occupancy, and indoor climate class); • Parts and inter-relationships comprising a building system (e.g., the behaviour of materials, components, equipment and sub-systems); • Parameters or indicators defining acceptable performance (e.g., aesthetics, health and safety, economy, sustainability, etc.); and • Methods, tools, and techniques for designing and analysing performance according to the parameters, interrelationships and conditions cited above. He too stresses the numerous interfaces between a building, its occupants, and the natural and built environment which he depicts in Figure 2 below (2014:8).


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Figure 2: Contemporary context for building per formance objec tives (K isek 2014:8).

K isek is one of the few authors that include the building impact on natural systems as a pillar of building performance. Whereas Hartkopf et al (1986) developed pillars of integrity and comfort, Kisek (2014) builds relationships between the constituent elements of a building system and the physical phenomena as depicted in Figure 3 below. He (2014) stresses that the key points from this relationship are: • The fundamental physical phenomena imposed on a material, component, or system drives its response or behaviour. • The suitability of a material, component, or system must, as a minimum, adequately address the imposed physical phenomena. • The complexity of problems increases dramatically as the design process proceeds from selecting materials, to arranging components, to integrating systems. Table 1: Physic, materials, components, and systems (Kisek 2014:9).

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What Kisek’s work does do is recognise the multi-functional nature of components and sub-systems: for example, a wall provides structural support, fire safety, and resistance to weather conditions simultaneously. Since all three of these functions must be satisfied, he argues that the selection process should be based on a hierarchy of physics, materials, components, and systems as a practical method for dealing with performance objectives. The challenge which arises is reconciling the performance objectives (representations of relationships) to the actual intellectual process (design), and that it is precisely in this interface that “artificial intelligence and expert systems have demonstrated that the linkages between knowledge representation and its application require sophisticated interpretation” (Kisek 2014:9). Kisek developed a general, extensible schema of building behaviour applicable to the whole system, as well as its constituent elements. He argues that by linking a number of simple schemata, complex behaviour may be described, if not quantitatively modelled: for example, the direct response of the building enclosure to the temperature, air pressure, and humidity difference between the indoor and outdoor environments results in heat loss and air leakage, while the indirect response influences thermal comfort and indoor air quality in the event that the building envelope provides low effective thermal resistance (excessive thermal bridging and/or insufficient insulation) and the condensation of moisture promotes mould growth (2014:11). Kisek (2014) notes that computational methods for the design a n d a s s e s s m e n t o f b u i l d i n g s y s te m s have not yet emerged, meaning that the integrative process of design will remain an exclusively human task for t h e t i m e b e i n g. I n t h e a b s e n c e o f c o m p u t a t i o n a l m o d e l l i n g, K i s e k h a s developed what he refers to as a Building

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3 Performance Objectives Framework (see Figure 3). He notes that the framework is “based on the premise that in the assessment or design process, the key consideration appears to be the performance objective or intent” where the “intent remains constant while the means of achieving the intent or objective continue to evolve with advances in technology” (2014:12). The framework, similar to the earlier work of Hartkopf et al (1986), consists of two primary elements: • The physical constraints which are imposed by site conditions and the limits or thresholds of the global environment and local ecosystem; and • The functional requirements of buildings that encompass occupant requirements, compatibility requirements, and physical requirements. Kisek argues that the predominant area of interest for building science is under functional requirements, and within this area further and more specific objectives are identified that constitute the basis for designing and/or assessing physical building system performance (2014:13).

Figure 3: Building performance objectives framework from a building science perspective (Kisek 2014:12).

Kisek notes that optimizing performance goes beyond compatibility between the structure, enclosure, interior, and services. It involves, he argues, the assessment of economic, social, and environmental parameters so that performance targets are attained affordably

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within the skill capacity of the industry. This, he suggests, means that innovation may be defined as achieving better performance and higher quality at less cost over the life cycle of a building (2014:13). In summary he argues that: • “Buildings are systems that must be appropriately integrated by designers to achieve defined levels of performance. • Building science provides a disciplined means of dealing with the physical requirements of buildings that is completely compatible with the architectural design and building construction process. • Innovation in modern architecture relies on building science and the systems approach to ensure that building performance meets the expectations of building owners, inhabitants, and society. • The context for building performance has more recently evolved to include issues of ecology and sustainable development. This expansion of performance parameters, coupled with increasing consumer expectations, has dramatically increased the complexity of buildings. Performance objectives frameworks and conceptual models have become necessary methodologies to assure all aspects of the integration of well performing building systems have been carefully addressed” (2014:14). Kisek’s reference to issues of ecology and sustainable development were earlier echoed in the work of Kibert and Groskopf (2005:1), who, in addressing what they refer to as ‘NextGeneration Green Buildings’ argue that such green buildings should have five major features: • Integration with local ecosystems; • Closed loop materials systems; • Maximum use of passive design and renewable energy; • Optimized building hydrologic cycles; and • Fu l l i m p l e m e n t a t i o n o f I n d o o r Environmental Quality measures.

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Kibert and Grosskopf (2005) share the view of Kisek (2014) and Hutcheon and Handegord (1983) with regard to design responding to local building practice: Kibert and Grosskopf (2005) note that “vernacular design is a technology or applied science that evolved by trial and error over many generations in locations all over the planet” and that “vernacular design is the closest approach to true ecological design available today” (2005:6). However, unlike Hutcheon and Handegord (1983), Kibert and Grosskopf (2005) argue that the “technological approach to high-performance green building is an evolution of current practices” and that the “key characteristics of the ultimate highperformance green building are based on incremental improvements in existing technology and are probably unlikely to be radical changes to today’s practices” (2005:7). Having stated that, they then conclude that the “next generation of green buildings will have to be radically different from today’s versions and will be designed using integrated systems approaches” (2005:7). Towards a high-performance green building framework The question arises as to why this difficulty around conceptualizing and defining highperformance building exists? Hutcheon and Handegord (1983:3-4) (in Kisek 2014:10) notes that: “The design of buildings has been, and still is, to a large extent, based on building practice. Changes have been slow and, in the main, have come about through an evolutionary process of trial and error. Building practice has been fundamentally an inheritance from the past, modified by factors such as climate, economy, social habits, local aesthetic values, and local resources of materials and skills. The evolutionary process works slowly under

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the influence of new factors; it is equally slow in rejecting the obsolete. The growth of scientific knowledge has led to great advances in the analysis and rational design of the purely structural functions of a building. There has also been a great deal of development in individual materials and components. As yet, there have been relatively small advances in dealing adequately with all of the combinations of elements and with the complex interrelationships of phenomena involved in the performance of an entire building. The reasons are not hard to find. It is sufficient to note that, even now, contemporary building science draws on the knowledge and experience of almost every branch of engineering science. We have long since past the point where we are content to rely on the ‘trial-by-use’ method of assessing changes in design, materials and construction. Many new and interesting materials, systems and methods of design and construction are offered each year. Those responsible for assessing and screening such new developments realize only too well the relative inadequacy of our present knowledge of the suitability of any given material or method. In addition, our standards of performance are continually being raised. As we reduce our major difficulties in turn, minor ones assume greater relative proportions, and we clamour for their reduction or elimination also, in the name of progress. The increasing state of knowledge appears less and less adequate as the demands upon it increase.” To develop a high-performance green building framework the following challenges will need to be resolved: Definition Two challenges emerge with regard to defining building performance: the first has to do with who determines what constitutes performance (the client, designer, user,


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society?) while the second has to do with the stage at which performance is measured (design stage, occupancy stage, or whole life?). One of the difficulties with the CIB developed conceptual framework for PEBBD is that the performance of the building is always unique to the specific users at the time of design. Since buildings have a long life, it poses a dilemma with regard to how performance is defined once the original users no longer use the building.

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Scope Determining what is included in â&#x20AC;&#x2DC;performanceâ&#x20AC;&#x2122; remains unclear from the literature review. While the scope was based on technical requirements to begin with, clearly the impact is on the user and needs to be considered. Similarly, more recent attempts have included environmental impacts, and most recently, resilience. Measurement and verification The demand for verification ranges from a strictly quantitative approach to a quantitative

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and qualitative approach to the setting of the expected performance temporally and spatially. The requirement for verification is more easily met through strictly technical performance indicators, while the qualitative verification becomes more problematic and gives rise to this dilemma of the impact on quality of life over time.

broader way of looking at building performance over the ‘Whole Facility Management Cycle’, with terms such as ‘total building performance’, ‘whole life performance’, ‘overall performance’ and ‘integrated building performance’ demonstrating the expansion of the concept. This is a concept that is not embedded in the construction industry.

New knowledge generation As Hutcheon and Handegord (1983:3-4) and Kibert and Grosskopf (2005:6) argue, the design of buildings has been, and still is, to a large extent, based on (current) building practice. However, unlike Hutcheon and Handegord, Kibert and Grosskopf (2005:6) call for radical green buildings on the one hand while stating on the other hand that “technological approach to high-performance green building is an evolution of current practices” and that the “key characteristics of the ultimate highperformance green building are based on incremental improvements in existing technology and are probably unlikely to be radical changes to today’s practices.” Quite how the next generation of green buildings are to be radically different from today’s versions without radically changing today’s practices is difficult to understand. As Hutcheon and Handegord (1983) note, “the increasing state of knowledge appears less and less adequate as the demands upon it increase.” From the literature review it is clear that significant growth in building physics knowledge is a prerequisite, as is the development of computational simulation. It may well be that this new knowledge generation will prompt greater innovation throughout the construction value chain.

Decision-support tools One of the more critical requirements is for tool(s) to assist industry stakeholders in making performance-related decisions. As can be seen from the literature, performancebased building requires dealing adequately with all of the combinations of elements and with the complex interrelationships of phenomena involved in the performance of an entire building. Guidance will have to be given in making choices, preferably through computational modelling at the design stage.

System thinking The literature calls for a move toward system thinking and integrated design in building practice. As stated earlier, the trend is toward a

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Conclusion A high-performance green building framework or model is needed to develop resilient designs, together with validated criteria, metrics, benchmarks, analysis tools, codes, performance standards, verification methods, and rating and certification programmes for measuring high performance and providing high-performance –based design guidance and standards to the design and engineering communities. At the same time, the framework will have to create an enabling environment to stimulate innovation within the building industry, reduce barriers to the deployment of high performance building technology, and promote whole building performance. Buildings are designed for long-life, and given the pace of environmental and societal change, predicting how buildings built today will be used in two or three decades time is almost impossible. It is imperative therefore those buildings deliver the highest level of performance possible to better meet the demands of the future. Included in the


3 performance requirement therefore should be the ability of a building to be adaptable. To do this will require that the knowledge base of the construction industry be substantially extended especially with regard to its understanding of building physics, computational simulation, and innovation.

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The international community has already made some progress in this direction and while significant challenges remain, the potential gains are substantial. Lessons from the international experience need to be learnt and used to inform the introduction of high performance green building into the South African construction industry.

References

• AIA 2005. High performance building position statements. [Online] Available from: http://www.aia.org/ practicing/groups/kc/AIAS077692 [Accessed: 2015-03-02]. • Becker, R. 2008. Fundamentals of performance-based building design, Haifa: Israel Institute of Technology. • Becker, R. and Foliente, G. 2005. Performance based international state of the art, PeBBu 2nd International SotA Report, Rotterdam: CIBdf. • Blachere, G. 1965. General consideration of standards, agreement and the assessment of fitness for use, Paper presented at the 3rd CIB Congress on Towards Industrialised Building, Copenhagen, Denmark. • Blachere, G. 1987. Building principles, Commission of the European Communities, Industrial Processes, Building and Civil Engineering, Directorate General, Internal Market and Industrial Affairs, EUR 11320 EN. • BPP 2015. Building performance defined. [Online] Available from: http://www.buildingperformanceprofessionals.com/buildingperformance.html [Accessed: 2015-03-02]. • BusinessDirectory 2014. Performance. [Online] Available from: http://www.businessdictionary.com/definition/performance.html [Accessed: 2014-12-15]. • CIB 2003. Performance based building: first international state-of-the-art report. Rotterdam, CIB Development Foundation: PeBBu Thematic Network. • Chemillier, P. 2011. Gérard Blachère (33) scientifique du bâtiment. [Online] Available from: http://www. lajauneetlarouge.com/article/gerard-blachere-33-scientifique-du-batiment#.VP2barD9mUk [Accessed: 2015-3-09]. • Costa, D. 2011. “Air quality in a changing climate.” Environmental Health Perspectives, 119(4):154-155.

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• CRISP 2001. Construction research priorities 2001: people, knowledge and industry improvement. London: CRISP. • Edwards, B. 2002. Rough guide to sustainability. London: Royal Institute of British Architects. • Fairclough, J. 2002. Rethinking construction innovation and research: a review of government R&D policies and practices. London: Department of Trade and Industry/Department of Transport, Local Government. • Foliente, G. (Ed.)1998. Development of the CIB pro-active program on performance based building codes and standards. BCE Doc. 98/232. Melbourne: CSIRO. • Foliente, G. 2000. “Developments in performance-based building codes and standards.” Forest Products Journal, 50(7/8), 12-21. • Foliente, G., Huevila, P.,Ang, G., Spekkink, D., and Backens, W. 2005. Performance based building R&D roadmap, PeBBu Final Report, Rotterdam: CIBdf. • Foster, B. (Ed.) 1972. “Performance concept in building.” Invited paper, Joint RILEM-ASTM-CIB Symposium, NBS Special Publication 361. Washington: US Government Printing Office. • Gibson, E. 1982. Working with the performance approach in building, Rotterdam: CIB Report Publication n.64. • Gross, J. 1996. “Developments in the application of the performance concept in building”, Proceedings of the 3rd symposium of CIB-ASTM-ISO-RILEM, National Building Research Institute, Israel. • Hartkopf, V., Loftness, V., and Mill, P. 1986. “The concept of total building performance and building diagnostics.” In Building performance: function, preservation and rehabilitation, ASTM STP 901, G. Davis, Ed. Philadelphia: American Society for Testing and Materials. • HPBCCC 2015. High-performance building congressional caucus coalition. [Online] Available from: http://www.hpbccc.org/ [Accessed: 2015-03-23]. • Kesik, T. 2014. Building science concepts. [Online] Available from: http://www.wbdg.org/resources/buildingscienceconcepts.php#ar [Accessed: 2015-03-02]. • Kibert, C. and Grosskopf, K. 2005. Radical sustainable construction: envisioning next generation green buildings.” [Online] Available from: http://www.cce.ufl.edu/wp-content/uploads/2012/08/ WhitePaper-RSC06.pdf [Accessed: 2015-03-23]. • Kibert, C. 2013. Sustainable construction. New Jersey: John Wiley and Sons. • Lewis, A., Riley, D., and Elmualim, A., 2010. Defining high performance buildings for operations and maintenance. [Online] Available from: http://buildinginformationmanagement.wordpress. com/2010/10/22/high-performance-building-definition-is-evolving-just-like-bim/ [Accessed: 2013-02-15]. • Lutzkendorf, T., Speer, T., Szigeti, F., Davis, G., le Roux, P., Kato, A., and Tsunekawa, K. (2008). A comparison of international classifications for performance requirements and building performance categories used in evaluation methods. [Online] Available from: http://www.irbnet.de/daten/ iconda/CIB6731.pdf [Accessed: 2015-02-27]. • Meacham, B., Bowen, R., Traw, J. and Moore, A. 2007. “Performance-based building regulation: current situation and future needs.” Building Research & Information, 33:2, 91-106, DOI: 10.1080/0961321042000322780 • New World Encyclopedia 2016. Code of Hammurabi. [Online] Available from: https://www.newworldencyclopedia.org/entry/Code_of_Hammurabi. [Accessed: July 7, 2016]. • NCTC 2008. Federal research and development agenda for net-zero, high-performance green buildings. Washington: National Science and Technology Council.

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• NFPA 2000. Performance-based primer: codes and standards preparation. [Online] Available from: http://www.nfpa.org/~/media/Files/Codes%20and%20standards/Standards%20development%20process/PBPrimerCombined.pdf [Accessed: 2014-12-15]. • NIBS 2008. Assessment to the US Congress and US Department of Energy on high performance buildings. Washington: National Institute of Building Sciences. • NIBS 2010. Designing for a resilient America: a stakeholder summit on high performance resilient buildings and related infrastructure. Washington: The National Institute of Building Sciences. • Oxford Dictionary 1985. The concise Oxford dictionary. Oxford: Oxford University Press. • PeBBu 2005. PBB international state of the art. PeBBu 2nd International SotA Report. [Online] Available from: http://www.pebbu.nl/resources/allreports/downloads/02_sota.pdf [Accessed: 2015-3-09]. • Pollio, V., Warren, H. 2005. Ten books on architecture. Stilwell: Digireads.com Publishing.

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greenline The range of fixing products with renewable resources.

Environmentally friendly and secure. The range of fixing products with renewable resources.

n construction, you also cannot do without a little extra environmental friendliness and resource efficiency. That is why we have developed our new greenline range, which has been certified by DIN CERTCO / TÜV Rheinland. As durable as the original, every green fischer anchor or mortar from this ange is made from at least 50 percent renewable raw materials. We have been undertaking numerous other environmentally friendly activities for many years as part of our environmental management system, which is certified in line with DIN EN ISO 14001. Find out more at: www.fischer.de/greenline


PROFILE: UPAT

UPAT – BUILD THE BIGGER PICTURE International fixing and fastening brand, fischer, is a global market leader in fixing technology and innovation. Founded by Artur Fischer in a simple workshop near Stuttgart Germany in 1948, the company has since grown to over 4000 employees worldwide. There are over 14 000 products available under the Fixing Systems division of fischer; and the company is still recognised by the significant number of patents it holds. The company has produced countless fixing solutions over the years for a very broad range of applications whilst maintaining a degree of flexibility to be able to develop tailor-made customer solutions. In Southern Africa, fischer is represented, distributed, marketed and manufactured under license by Upat S.A. (Pty) Ltd. It can be found in good hardware stores nationwide; and for industrial applications can be bought directly from Upat S.A. (Pty) Ltd. – Upat S.A. (Pty) Ltd, a 100% South African owned business, commenced trading in 1983 as the sole Southern African distributor of the Upat range of construction fasteners. At the outset, Upat S.A. (Pty) Ltd was committed to the building industry with not only a range of anchor bolts but rotary hammer drilling machines, tungsten tipped masonry drill bits, powder actuated tools and allied building and construction products. Today, Upat officially represents several International companies in Southern Africa. Such as: STABILA market leader in spirit levels, measuring equipment and latterly construction lasers; Eibenstock German Engineered diamond coring and associated products; Starmix specialised vacuum cleaners for industrial use and Milwaukee, leaders in portable heavy-duty power tools for the professional user. In addition to an extensive quality product range offered by these world renowned brands,

Upat also provides its customers with a range of services and added value benefits such as: • Timeous Deliveries: The Company has branches in the top commercial centres around South Africa and operates a fleet of vehicles nationwide, ensuring a 24 hour delivery of stocked items. • Technical Back-Up: In addition to technical sales guidance, Upat offers qualified Engineering services for on-site testing and application advice. • On-Site Training: Upat offers free on-site training to all external operators of Upat products. • In-House Training: All internal technical staff engage in thorough and regular training on all new and existing company products and services. • Tool Repairs: Qualified technicians are able to repair all tools from the current product range. • Warranty: All power tools come with a full service warranty valid for one year from date of purchase. • Professional Counter Sales: Should contractors or end users wish to buy directly from their offices, professional counter sales representatives will be able to offer advice on the best possible product needed for your application. • Warehousing: All stock is originally received and warehouse at the Upat Head Office in Johannesburg. As a result, the company has developed intricate operations systems to handle all logistic queries. Upat offers something for every aspect of your building cycle that is guaranteed to be of the best quality. They also provide you with technical support and expertise too; so if you choose Upat as your supplier of choice, they will help you BUILD THE BIGGER PICTURE. THE GREEN BUILDING HANDBOOK

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GBCSA rolls out Green Building Certification Tools across most sectors

Manfred Braun

Image by GBCSA


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reen Star SA certifications by the Green Building Council South Africa (GBCSA) have grown exponentially since the organisation’s inception in 2007. The cumulative number of certifications more than doubled between end 2014 and end 2015, from 75 to 157, and in fact reached 200 in September 2016 Green Star SA Rating Tools are used to assess the environmental impact of a building or tenancy’s design, construction and operation, and are now also available to rate neighbourhood scale projects. A project cannot publicly claim a Green Star SA rating unless the GBCSA has certified the project. The GBCSA has also released two other rating tools, namely the EDGE and Energy Water Performance tools. The GBCSA currently operates ten rating tools. These are: • Green Star SA – Interiors v1: a new rating tool that assesses the environmental attributes of interior fit-outs; • Green Star SA – Office v1.1, for new office construction projects and major office refurbishments; • Green Star SA – Public and Education Building v1, which assesses new or significantly refurbished public and education developments; • Green Star SA – Multi Unit Residential v1 tool assesses new multi unit residential developments as well as major refurbishments of existing multi unit residential developments or conversions; • Green Star SA – Retail Centre v1 for new retail centres as well as major retail centre refurbishments • Green Star SA – Existing Building Performance tool, which assesses the environmental performance of existing buildings in operation, taking a 12 month snapshot of the building in operation and rating this; • Green Star SA – Socio Economic Category is an optional additional category available to interiors and all new building tools, which recognises the socio-economic

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achievements and initiatives of green building projects; • Green Star – Communities tool is a rating tool that rates the sustainability credentials of the design and construction of a neighbourhood scale project; • The Energy Water Performance tool is a tool that will allow office buildings to benchmark their energy and water performance against industry norms, and is especially powerful for property portfolio owners; and • The EDGE tool is a resource efficiency tool for the design and construction of new and major refurbishments of residential projects, which covers energy, water and embodied energy of materials. Going into more depth on each of the tools above, the Green Star SA – Interiors v1 Tool allows each tenant to have their unique environmental design initiatives fairly and independently bench-marked. The tool rewards high-performance tenant spaces that are healthy, productive places to work; are less costly to operate and maintain; and have a reduced environmental footprint. This rating tool has been developed to cater for a broad range of tenancies, including but not limited to office, retail and hospitality fitouts. The Green Star SA – Office Tool was the first to be launched into the South African market in 2008 and all certifications are undertaken using Version 1.1. Two certifications are awarded through this tool: Design and As Built. The Green Star SA – Public and Education Building Tool awards Design and As Built ratings, and can apply to community centres; libraries, museum and gallery buildings; education buildings, such as schools; higher education buildings (universities and colleges); theatres, cinemas and music halls; places of worship; and convention or exhibition centres. The Green Star SA – Multi Unit Residential Tool assesses a development with three or

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more dwelling units, common property, shared services and infrastructure among dwellings and an applicable management entity such as a body corporate, home owners association or management operator. The tool assigns a Green Star SA rating to the dwellings, common property and shared services and infrastructure on the basis of design attributes. The tool can be used for apartment buildings; blocks of flats; townhouses; detached or semiattached single access housing developments of three or more dwellings, such as gated communities, retirement villages, golf estates; and self-catering student accommodation and multi-family buildings which include communal kitchen/living/ablution facilities. The EDGE tool is also targeted at residential developments, but is a much lighter and simpler rating tool focusing on resource efficiency on only energy, water and embodied energy of materials, for which at least a 20% improvement on each must be achieved above the baseline. EDGE is also only currently available for projects with three or more dwellings. The Green Star SA – Retail Centre v1 Tool awards Design and As Built certifications to a typical retail centre that has common mall areas and shared building infrastructure among tenancies. The tool assigns a Green Star SA rating to the base building and its services on the basis of design attributes. Tenant fit-outs are not rated under this tool. The Green Star SA – Existing Building Performance Tool (EBP) covers the same environmental categories addressed in the Green Star SA new building tools but the focus is on the efficient operations and management of the building measured over a 12 month period to maintain optimal performance. The rating is valid for a period of three years to ensure the building is continually well operated and maintained. Items such as energy and water measurements, management policies and plans are required to achieve the rating. The tool also addresses the relationship between

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landlord and tenants, setting up a win-win situation with the green lease toolkit. A rating is awarded from 1 to 6 Stars, acknowledging the journey that existing buildings are on, where each building’s current state of performance is unique and allows for progress over time to be measured and benchmarked. A key component of the energy and water categories of the Existing Building Performance Tool is the GBCSA’s Energy Water Performance Tool (EWP). Currently developed for Office buildings, this tool is a free resource which allows comparison of energy and water performance against industry benchmarks. It allows existing building owners and/or portfolio managers to easily benchmark their properties in terms of energy and water performance, informing key investment decisions. The EWP accounts for 40% to the Existing Building Performance certification but is available as a separate certification of energy and water performance. The Green Star SA – Socio Economic Category (SEC) (pilot) applies to developments or projects which qualify for interiors or new build Green Star SA tools. Projects can also target SEC credits as innovation points if they don’t want to target a full SEC rating. And finally, the Green Star SA – Communities tool is a rating tool that rates the design and construction of neighbourhood scale projects, but rather than rating the individual buildings it rates the urban design and public spaces that connect the buildings, and rates the process that the project went through to develop the project design. The GBCSA’s education programmes encompass a number of courses geared towards built environment professionals. The Green Star SA Accredited Professional programmes have been designed to correspond with the three broad types of rating tools on offer: new buildings; existing buildings interiors and communities. The GBCSA also offers an EDGE Accredited Professional programme. The organisation’s programmes give the learner an in-depth


4 and interactive learning experience and better equip them to support their project teams in designing, constructing and operating greener buildings and communities. The GBCSA typically utilises a blended learning model to deliver the very best training for the use and application of the rating tools for professionals working in the built environment and property industries. This model combines the physical and virtual classroom, allowing students to learn as individuals in their own time and then apply their learning to scenario-based problems when coming together with their peers. This model has shown in studies to increase student engagement, attendance and performance. For the three-part Green Star AP programmes for new builds, interiors and existing buildings, participants attend face-to-face workshops, which offer the opportunity to experience Green Star SA tools in action. After attending, participants can elect to continue on to the corresponding online Accredited Professional course and then complete the online exam in order to obtain Green Star SA accreditation. In addition to the Accredited Professional programmes, the GBCSA is launching a regular Masterclass Series that will offer a deep dive into various aspects of green building. This

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will cover topics such as rooftop PV, water, acoustics and commissioning. These three-anda-half hour sessions will equip green building professionals, architects, engineers, quantity surveyors, landscape architects, interior designers, project managers, developers and contractors with a greater understanding of particular green building aspects. The GBCSA is par ticipating in a groundbreaking new project alongside the World Green Building Council which aims to ensure that all buildings are “net zero” by 2050. As part of this drive, the GBCSA is offering Net Zero Educational Workshops that are aimed at built environment professionals, particularly developers, architects, engineers and sustainability practitioners. The workshops will include aspects of reducing a building’s footprint to net zero or net positive energy, carbon, water and waste, and exploring regenerative design solutions and ways of thinking. They will have a strong focus on systems thinking and integrated design. The GBCSA will be launching a net zero certification system in due course. For more information on the various rating tools and the GBCSA’s education programmes, please visit www.gbcsa.org. za or call 086 1042272.

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Foundations for a Greener Tomorrow

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elgotex Floors’ Sustainability Report (aka ‘Our Green Journey’) details the company’s ongoing green journey, which is their vision to ensure a greener tomorrow for all its stakeholders.

Their growing ‘Eco Collection’ of carpets, backings and underlays contribute significantly towards green design, but Belgotex’s focus is on resource efficiency and cleaner production, rather than simply producing a range of green flooring materials. “Our main goal is to operate a green factory wherever economically and environmentally feasible,” explained Kevin Walsh, Chief Operations Officer (COO) at Belgotex. “For us ‘green’ makes good business sense and extends way beyond mere ‘green sensationalism’. It’s such an intrinsic part of our DNA – our management philosophy – that it helps us maintain our competitive advantage,” he added. Through their continued efforts to improve production processes as well as their finished products in order to offer market-leading flooring, Belgotex centres its operations around the three pillars of sustainability (environmental, social and economic) and it is here where the greatest gains are being made in terms of sustainability. Under Walsh’s watchful eye the company has developed an environmental policy that addresses resource efficiency and cleaner production against environmental imperatives and product responsibility. Cognisant of the fact that synthetic floorcoverings (carpets, artificial grass and vinyl) can have a negative impact on the health and wellbeing of humans

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as well as the environment, Belgotex designs and develops its products under the following sustainable guidelines: • Extending the life of an existing product through responsible manufacturing techniques and processes. • Developing products that can be reworked in their existing form. • Using raw materials that pass the company’s stringent health and eco-toxicity assessments and that can be recycled at the end of their useful aesthetic life. • Using recycled content whenever it is economically and environmentally feasible. In living up to these new policy guidelines the company’s sustainability efforts are starting to pay off, which is cause for great pride within Belgotex. Belgotex Floors recently earned the coveted GreenTag eco-label certification after achieving another significant sustainability milestone. The first South African flooring company to be awarded the internationally recognised ‘Level A’ GreenTag certification (called GreenRate™), Belgotex


PROFILE

are able to offer specifiers maximum credit points (100%), across all Green Building Council interiors rating tools, for specifying their product. In addition, the company also received a ‘Silver’ quality rating in the lifecycle performance analysis – called LCARate™ – that recognises Belgotex products as “very good” against sustainability performance indicators. As the leading flooring manufacturer in Africa, Belgotex are continually pushing the limits of operational efficiency, seeking out ecologically sustainable manufacturing methods and developing eco-friendly products. Careful examination of their operations has identified their use of raw materials, energy management, carbon management, water management and air quality as making significant contributions towards their sustainability performance. Analysis of the use of natural resources in their manufacturing operations (as well as the energy used in production) enables Belgotex to continuously invest in new technology in order to enhance their existing products as well as to develop new ones. These upgrades have reduced energy and/or raw material consumption, without any loss of productivity or quality. Raw Materials A number of key inputs to Belgotex’s products are derived from non-renewable fossil fuel products. To minimise the risks posed by raw material depletion and climate change, Belgotex are constantly seeking out new, more sustainable inputs. The company is also committed to innovation within its product lines and manufacturing processes. Belgotex continues to strive to increase recycled content within its product range by implementing innovative raw material input strategies. The raw materials for several eco-products are derived from post-industrial and post-consumer waste such as Green underlay, Sportec Color rubber flooring and Grimebuster walk-off mats. The bestselling Berber Point 920 carpet and other needlepunch ranges are made with a blend of polypropylene and recycled Eco Fibre. This Eco

Fibre is manufactured using post-production waste, which is re-pelletised by utilising the cutting-edge Erema recycling machinery. The input of this recycled content in their production process considerably lowers the embodied energy associated with the use of virgin raw material. Nexbac Eco modular tile backing contains up to 70% post-industrial waste (fly-ash), which is used as a filler in the backing. Carbon Management Apart from the raw material supply, energy and water consumption, greenhouse gas emissions are another major consideration, since the majority of Belgotex’s manufacturing processes are driven by fossil fuels. In an attempt to positively manage this risk (and to avoid a potential carbon tax liability), Belgotex aims to track and mitigate its effects on the environment. In its 7th year of quantifying its carbon footprint, Belgotex is pleased to announce a ~22% reduction in its carbon footprint thanks to the implementation of its integrated carbon management systems. Energy Management Belgotex incorporated a resource efficiency and cleaner production strategy that resulted in the reduction of non-renewable energy consumption by ~12%. In order to move the company towards more sustainable energy sources and to alleviate reliance on the national energy utility, numerous energy optimisation initiatives have been put in place, including extensive plant upgrades and the installation of more energy-efficient equipment. This was achieved by amongst others, the R17million roof-mounted photovoltaic (PV) solar power plant that provides around 5% of the company’s annual energy requirement. By reducing their reliance on coal-fired energy sources, the plant also offset ~2.5% of carbon emissions, reducing them by 1 386 tons per annum. A further 5% reduction target is anticipated with the possible installation of another 1MW solar plant in future.

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Water conservation The company’s Rainwater Harvesting Initiative (RWH) in 2015 uses rainwater stored from the company’s roofs in non-critical applications, and this has achieved considerable reductions in water consumption. Future targets for water usage are set at reductions of up to 45%. Not only does this protect a scarce resource that is increasingly pressurised by severe drought conditions (with projections of a deepening crisis), this project reduced operational costs due to decreased purchases from the municipality. Their investment also allows certain production processes to continue during unexpected leakages or breakdowns in the municipal supply. Many other water-saving initiatives (such as converting to 100% solution-dyed yarn production) have resulted in significant water, chemical and energy savings. Waste management Waste minimisation programmes form part of the company’s EMS (ISO14001). Waste is monitored and measured continuously to ensure that progress targets are met. In line with the well-known 3R’s of waste management – Reduce, Reuse and Recycle – Belgotex seek to reduce inputs (for energy/ resources), reuse materials and recycle waste from its operations wherever possible. Reduce Stackable, mobile metal crates have replaced cardboard boxes or packaging of any kind in the company’s yarn-processing operations, thereby reducing the amount of packaging to be recycled or sent to landfills. Bulk storage silos and stretch wrap are used wherever possible to eliminate the need for raw material packaging. Reuse Belgotex’s Flooring Reclamation programme collects used or uplifted carpets from central collections points to be cleaned and sent to

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NGO’s such as KZN Wildlands for re-use and redistribution to impoverished communities in their “Green-preneur” project. Acquisition of innovative bit-winders has seen the elimination of a complete stream of waste by creating Grade 1 yarn from waste creel-ends. Recycle The acquisition of a new R5-million Erema machine enables the company to recycle production waste back into Eco Fibre, which is used in the production of its standard ranges. The Erema machine offers up to 20% energy savings, resulting in lower production costs and reduced CO2 emissions, and has effectively reduced Belgotex’s waste rates from their carpet production processes to close to zero. Indoor Air Quality/Health & Eco-Toxicity Assessments Belgotex carpets and underlays have been tested and contain no harmful volatile organic compound ( VOC) emissions and meet the strict requirements for the Green Building Council’s indoor environmental quality. All raw materials undergo stringent health and eco-toxicity assessments to ensure safe, quality product offerings. Belgotex offers a world of choice, and has made the world their first choice. (033) 897-7500 | Cape Town (021) 763-6900 | JHB (011) 380-9300 www.belgotexfloors.co.za


The Water Research Commission of South Africa moved to a new office development that consists of two towers on a shared podium. The towers each comprise 6 storeys with 5 basement levels. The towers have entrances on the south facing façades, which includes a central atrium used for vertical circulation, light and natural ventilation. Sun- control measures include steel perforated mesh panels and horizontal fins. All elevations use high performance glass which limits the noise from the adjacent roads and ensure maximum thermal comfort. The base parking floors have been designed to be vertically ventilated and storm water attenuation measures have been incorporated into the design to collect and manage the flow of surface water across the site. The minimal soft landscaping proposed within the site boundary consists of trees and groundcover shrubbery along the edges of the building and to the perimeter of the forecourt parking area.

Building features include: • Low pressure Variable Air Volume

(VAV) Air-cooled system and VSD fans in basements connected to CO monitors

• Fresh air provided at a rate of 10ℓ/s/p. • High level of thermal comfort for 95%of the usable area.

• Optimum quantities of outside air through CO2 monitoring.

• Efficient lighting & occupancy sensors “Enjoy your new offices and let us all be inspired by this wonderful opportunity and beautiful environment” - Adriaan

• Energy uses of 100kVA or greater and all major water uses are sub-metered & controlled via BMS • Rainwater harvesting & filtration used to flush toilets and urinals with efficient water fittings (taps, shower heads, WCs) and for irrigation • 84.5% of usable area has direct line of sight to the outdoors • Paints, adhesives & sealants and carpets with low or no VOC and Formaldehyde minimisation


Vertical Flow and Horizontal Flow Constructed Wetlands

Mandla Dlamini


C

onstructed wetlands can provide an elegant solution to domestic grey water treatment. The system is completely organic without the addition of any chemicals and it in many cases improves the aesthetics of the environment. This review will focus on two common types of constructed wetland, Horizontal subsurface flow wetlands (HSFW ) and Vertical flow wetlands (VFW). It should be noted that even though these systems share many common elements, and visually they may appear similar, the design, construction and maintenance aspects of each system are different. As their names suggest, the difference in these wetlands stems from the direction of flow of effluent through the wetland. In horizontal subsurface flow wetlands the effluent will flow horizontally and be collected at the end through an outlet, whereas in vertical flow wetlands the flow is vertical, with inlet pipes near the top surface of the filter bed and drainage pipes at the bottom of the filter bed. Experienced wetland designers and construction experts can merge wetland types to form hybrid systems that contain elements from both systems and other alternatives. This review will focus on these two well-defined systems and their properties. The papers reviewed in this article suggest in general that constructed wetlands are an economical option when it comes to domestic and grey water treatment. However, wetlands are not suited for treating Blackwater i.e. effluent containing solids and faecal matter. If it is decided that Blackwater should be treated, a pre-treatment step is required. Pre-treatment steps will vary on the anticipated effluent, but in general it consists of a settlement tank to which the solids and grease are separated from the effluent water through a settling stage. A VFW constructed in Vidrare Bulgaria is given as a case study where a pre-treatment stage is

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included for the constructed wetland. Where a functioning sewerage system is in place, it is ideal for black water to be disposed of through that through that system. A combination horizontal and vertical subsurface flow wetland used in Tirana Albania was also reviewed. Constructed wetland Elements The diagrams shown below give long section details of horizontal subsurface and vertical wetland systems.

Figure 1: Horizontal subsurface flow wetland (Tilley et al, 2010)

Figure 2: Vertical flow constructed wetland (Tilley et al, 2010)

Constructed wetlands are made up of various sub-components, each with their own function and description. Levelling layer: This layer can be in situ material or suitable gravel material brought in to enable the dimensions and tolerances given in the design to be achieved. Wetland plants: Local wetland plants are recommended for use in wetlands, this is to avoid

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invasive species affecting the local ecosystem negatively. The plants add to the aesthetic appeal of the wetland and can serve as a habitat for wildlife. Wetland plants have their roots in the filtration material and keep the filter bed permeable. Chanel/Basin dimensions: The size, depth and slope of the channel should are subject to the available area and the expected grey water/effluent discharge. For horizontal flow wetlands Tilley et al (2008) recommend an area of 5 to 10 m2 per person equivalent (being served by the wetland). The wastewater gardens information sheet (2010) recommends an area of 3 to 5m2 per 150 Litres of discharged effluent for temperate to warm climates for horizontal subsurface flow wetlands, this value can be halved for vertical flow wetlands. Hoffman (2001) suggests that the area per Chanel/Basin dimensions: person equivalent used issubject dependent The size, depth and slope of the channel should are to the available areaon and thethe expected grey water/effluent discharge. For horizontal flow wetlands Tilley et al (2008) climate and type of system, the following table recommend an area of 5 to 10 m per person equivalent (being served by the wetland). is applicable: 2

The wastewater gardens information sheet (2010) recommends an area of 3 to 5m2 per 150 Litres of discharged effluent for temperate to warm climates for horizontal subsurface flow wetlands, this value can be halved for vertical flow wetlands.

Table 1: Recommended design values for Hoffman (2001)areas suggests that the area per person equivalent used is dependent on the wetland climate and type of system, the following table is applicable:

Table 1: Recommended design values for wetland areas Cold climate, annual average T< Cold climate, annual average T> 10o C 20o C HFB VFB HFB VFB Area per person 8 4 3 1.2 equivalent (m2/p.e.) Design Value

Wetland liner Wetland liner Constructed wetlands integrate well aesthetically into the surrounding environment; however it is important that waste water doesn’t leach integrate through the system into well natural Constructed wetlands ground water and the water table. Thus the incorporation of a barrier in the form of an aesthetically impermeable layer/membrane, the into following optionsthe are found insurrounding the literature: environment; however it is important that • Plastic or HDPE membrane • Concrete layer doesn’t leach through the system waste water • Clay layer into natural ground water and the water table. To protect the membrane from root penetration and burrowing from wildlife, Albold et al Thus the incorporation of a barrier in the form (2008) recommend using a geotextile material underneath the impermeable membrane. of an impermeable layer/membrane, the Filter bed material: following options in materials, the literature: In general, ideal materials for use in are the filterfound bed are granular with no fines. The bed material ideally should permeable enough to allow effluent to seep through yet hold • filter Plastic or HDPE membrane the effluent for long enough to allow for filtration. • TheConcrete layer selection of materials for the filter bed is probably the most critical design consideration, • the Clay layer material should host the plant life, trap solids, allow effluent to seep through and be in service for long periods before eventually clogging.

For the filter materials small, round gravel (3-32 mm) is commonly used to fill the bed to a depth ranging between 0.5 and 1m. One important characteristic of the material is that it should not clog easily, thus fine materials are not suitable for use in the filter. (Tilley et al, 2008). It is crucial that the gravel or sand is clean, washed and without impurities. According to the THE GREEN BUILDING HANDBOOK 96 Wastewater Gardens Information Sheet (2010) volcanic rock is the best filtration medium but

To protect the membrane from root penetration and burrowing from wildlife, Albold et al (2008) recommend using a geotextile material underneath the impermeable membrane. Filter bed material: In general, ideal materials for use in the filter bed are granular materials, with no fines. The filter bed material ideally should permeable enough to allow effluent to seep through yet hold the effluent for long enough to allow for filtration. The selection of materials for the filter bed is probably the most critical design consideration, the material should host the plant life, trap solids, allow effluent to seep through and be in service for long periods before eventually clogging. For the filter materials small, round gravel (3-32 mm) is commonly used to fill the bed to a depth ranging between 0.5 and 1m. One important characteristic of the material is that it should not clog easily, thus fine materials are not suitable for use in the filter. (Tilley et al, 2008). It is crucial that the gravel or sand is clean, washed and without impurities. According to the Wastewater Gardens Information Sheet (2010) volcanic rock is the best filtration medium but other materials such as limestone, river rocks, recycled concrete and recycled crushed glass can also be used. Hoffman (2011) recommends the following grain size distribution envelope for sand used in the filter bed. Drainage pipes: These are used in vertical flow constructed wetlands to collect effluent that has been through the system. Inlet: The inlet design should allow effluent to spread over the entire breadth of the channel.


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The wetland is designed to treat waste water (without sludge) from the home; this includes water from toilets and water used to wash diapers.

Figure 4: Wetland inlet with large rocks (cobbles) to prevent clogging (Hoffman, 2011) Outlet The outlet should control the water level within the channel, it should allow for the tapping of excess effluent should the water level exceed the desirable level and the it should be closed Figure 4: Wetland inlet with large rocks (cobbles) to prevent clogging (Hoffman, 2011) off should the water seep to quickly through Outlet the system and not adequately. The The outlet should control the water levelbe withinfiltered the channel, it should allow for the tapping of excess effluent should the water level exceed the desirable level and the it should be closed outflow of effluent can be controlled by an off should the water seep to quickly through the system and not be filtered adequately. The outflow of effluent canstandpipe. be controlled by an adjustable standpipe. adjustable Table 2: Comparison of HSFW and VFW’s

Flow type

Elements Capital cost Efficacy Space requirement Maintenance

Systems in summary Horizontal Subsurface flow wetlands Gravitational Impermeable membrane Filter bed material Inlet Outlet Wetland plants

Low to medium Medium High Low to medium

Vertical flow constructed wetland Mechanical, Gravitational Impermeable membrane Filter bed material Drainage pipes Inlet Outlet Pumps Wetland plants Medium Medium to high Low Medium

Case study: Vidrare Bulgaria, Vertical flow wetland Table 2: Comparison of HSFW and VFW’s

This case study’s subject is “The Home of Handicapped Peoples’ constructed wetland in Vidrare, Bulgaria.” Constructed in 2008, the wetland treats domestic waste water coming from the home, which has a capacity of 95 beds. The type of wetland is a vertical flow wetland.

Case study: Vidrare Bulgaria, Vertical flow wetland This case study’s subject is “ The Home of Handicapped Peoples’ constructed wetland in Vidrare, Bulgaria.” Constructed in 2008, the wetland treats domestic waste water coming from the home, which has a capacity of 95 beds. The type of wetland is a vertical flow wetland.

Design considerations The guidelines/standards/codes used for the design of the constructed wetland are the DWA A 262 2006. Given that the wastewater would have solids, a pre-treatment step was required to collect/settle the sludge. For this purpose a settling tank was designed taking into consideration the following issues: 1. Settling volume: The volume required to allow solids to settle to the bottom of the settling tank. 2. Sludge storage: This volume is affected by how much sludge is deposited and the frequency of sludge removal for treatment in an external facility. With the solids removed a vertical flow wetland was designed to treat the effluent.

Figure 5: Envisioned vertical flow wetland

In determining the wetland area, the German design standard (SWA A 262 2006) was used. It recommends a wetland area of 3.5 cubic metres per Person equivalent. A total of 76 PE’s (person equivalents) needed to be served by the constructed wetland. Therefore a design area of 266 m (wetland depth = 1m) was specified. The wetland was subsequently divided into two filter beds of 133 m2 each.

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5 Figure 7: Wetland after filter materials and gravel placed ready for planting.

Figure 7 shows the wetland with all the required materials in place and ready for planting the wetland plants.

hot dry summers up to 40 degrees Celsius and cold wet winters down to 8 degrees Celsius. Constructed wetland in Tirana, Albania A combination of vertical flow and horizontal subsurface flow wetland was used to treat

waste water from the SOS childrenâ&#x20AC;&#x2122;s village in Tirana, The village in Table 3:coming Design data (Kinjali, et Sauk, al, Albania. 2012) Tirana has thirteen houses for orphans and other children who do not have conventional family structures. Each house has 5 to 7 children in residence, plus one adult taking care of Data informing the ofThethe them. In total about 500 people live, visit ordesign work in the village. climate wetland is Mediterranean, is with hot dry summers up to 40 degrees Celsius and cold wet winters down to 8 degrees Celsius. given in table 3. Table 3: Design data (Kinjali, et al, 2012)

Figure 6: Wetland before filer material and gravel placed Figure 6 shows longitudinal drainage pipes, which will collect filtered effluent and convey it to the outlet. The vertical flow wetland is lined with HDPE liner 15.mm thick.

Type Total population at full occupancy Total waste water flow rate Per capita WW generation rate Design hydraulic loading BOD concentration (estimated) Total BOD load Area of filter bed I (Vertical) Area of filter bed II (Horizontal) Total area Area per population equivalent Hydraulic load, bed I Hydraulic load, bed II BOD load, bed I

Value

Unit

220 16.8

P.E. M3/d

76.4 80

L/cap/day L/P.E.

300 5 330

mg/L kg/d m2

220 550

m2 m2

2.5 m2/P.E. 50.9 L/m2 6.4 L/m2 15.3 g/m2/d

Data informing the design of the wetland is given in table 3. The wetland was constructed during the course The wetland was constructed during the course of 2009, with the planning phase Septemberthe 2008. The horizontal flow constructed was operational in ofcommencing 2009,inwith planning phasewetland commencing 2010. inThe constructed September 2008. horizontal flow wetland system uses the existingThe sewer network and contains the following components: a) a settling tank for separation of the suspended solids, b) a pump chamber for application of the wastewater to the filter beds, c) a sludge drying bed, d) three filter beds constructed wetland was operational in 2010. (subsurface flow) for treatment and e) a storage tank for the treated wastewater for reuse on irrigation plots with overflow into the storm water drain. The constructed wetland system uses the This combination of constructed wetlands consists of two vertical flow wetlands (named IA and IB) and one horizontal flow wetland. The two vertical flow wetlands will be used existing sewer network and willcontains the alternatingly, where by effluent from the vertical flow wetlands be transferred to the horizontal flow subsurface wetland. Each vertical flow bed is fed for one week, and then allowed to recover for a week while the other verticala) flow bed in use. following components: a issettling tank for separation of the suspended solids, b) a pump chamber for application of the wastewater to the filter beds, c) a sludge drying bed, d) three filter beds (subsurface flow) for treatment and e) a storage tank for the treated wastewater for reuse on irrigation plots with overflow into the storm water drain. This combination of constructed wetlands consists of two vertical flow wetlands (named IA and IB) and one horizontal flow wetland. The two vertical flow wetlands will be used alternatingly, where by effluent from the vertical flow willonebe transferred Overall this project was wetlands very successful, however problem that arose from the to construction of the wetland included blockages and clogging in distribution pipes due to poor the horizontal flow subsurface wetland. Each vertical flow bed is fed for one week, and then allowed to recover for a week while the other vertical flow bed is in use. Overall this project was very successful, however one problem that arose from the construction of the wetland included blockages and clogging in distribution pipes due to poor performance of the pre-treatment stages, which include settlement of solid particles and grease separation. Settling tank/Sludge separation

Pump

Figure 7: Wetland after filter materials and gravel placed ready for planting.

Vertical Flow subsurface wetland A

Vertical Flow subsurface wetland B

Horizontal flow subsurface wetland

Figure 7 shows the wetland with all the required materials in place and ready for planting the wetland plants. Constructed wetland in Tirana, Albania A combination of vertical flow and horizontal subsurface flow wetland was used to treat waste water coming from the SOS childrenâ&#x20AC;&#x2122;s village in Tirana, Sauk, Albania. The village in Tirana has thirteen houses for orphans and other children who do not have conventional family structures. Each house has 5 to 7 children in residence, plus one adult taking care of them. In total about 500 people live, visit or work in the village. The climate is Mediterranean, with

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Treated Effluent

Figure 8: Flow diagram of stages involved in treating waste water, Tirana SOS village wetland, Albania


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Figure 9: Lining and drainage piping of a one of the Vertical flow wetlands

The beds were sealed from the natural ground material using polyethylene liner (HDPE). In addition to the liner, a geotextile was used in conjunction with the synthetic liner to separate the natural ground from the filter bed. Why constructed wetlands fail

Figure 10: A failed wetland system in Kleruu, Tanzania (Kimwaga et al, 2013)

Constructed wetlands, well designed, constructed and maintained can provide many years of service. In cases where one or more of these 3 stages are poorly executed, constructed wetlands can be an unsightly cause of environmental degradation and damage. This part of the paper aims to learn from constructed wetland failures from various parts of the world. Turkish and Tanzanian constructed wetland failures “There are 51 constructed wetlands in the Kayseri Province of Turkey and more than threefourths have some kind of structural failure and

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are not operating properly”. Turkish experience in wetland construction is fairly new, with the first wetland being constructed in the year 2004. All 51 constructed wetland systems studied by Gokalp et al (2014) were horizontal subsurface flow constructed wetlands with a septic tank pre-treatment stage. After conducting site visits to the 51 facilities Gakalp (2014) reports “Among the 51 constructed wetlands, only a couple of them are partially operating. The rest have turned into swamp like systems with several wastewater pondings, partial plantation, and weed invasion.” Common problems identified were: Poor Planning and design Kimwaga et al (2013) state that a major issue affecting wetland success or failure is information required for the design. Hydrological budgeting which relates to the amount of effluent expected to be treated by the system. Kimwaga et al (2013) state that in many cases this information is just not available; therefore designers are either forced to make assumptions or use data from literature to inform their decisions. Site selection: Depending on the region and climate of the area in question, choosing an appropriate location for the wetland is essential. An important consideration when doing this is ensuring that the site ensures the structural integrity of the wetland. Examples of poor site selection include wetlands constructed in locations where flooding and strong runoff is likely to erode the wetland materials. Gokalp (2014) defines a characteristic of well suited wetland sites as being “not on the flood plain”. Clogging: The term "substrate clogging" summarizes several processes which lead to a reduction of the infiltration capacity of the substrate surface. Substrate clogging

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leads to an extremely fast failure of the treatment performance of the system (Gkalp et al, 2014). This was the most common problem found with the wetlands investigated in the work by Gokalp (2014). A suggestion that wetlands are very sensitive to the hydraulic load is made, stating that in many cases wetland clogging is caused by under-sizing of the wetland dimensions. In many of the wetlands studied by Gokalp (2014) the area per person equivalent using the wetland was significantly lower than the recommended value. Gokalp et report numerous cases where the Area per person equivalent was as low as 0.9m2 whereas the recommended values range between 3 and 5m2.

constructed wetlands of Kayseri. Since a synthetic liner was not used and slopes were not able to be compacted properly, leakage was observed in some villages through the slopes of basins”, Gokalp et al (2013).

Planting failure: Using reed/plants appropriate to the climate and soil conditions of the selected area, failures in reed bend include, the reed dying due to competition from weed infestation, low planting densities, poor harvesting practices and poor maintenance.

Conclusion With water utilisation increasing and its supply becoming vulnerable due to phenomena such as global warming, the re-use and treatment of water has become necessary for man to survive. Domestic grey water recycling can play an important role in ensuring water is used more efficiently. Vertical and horizontal constructed wetlands, when implemented correctly, can be an economical and environmentally sustainable way of treating grey water.

Leakage: The use of a synthetic durable liners such as PVC (Usually polyvinyl chloride (PVC), propylene based materials were not used to prevent leakage. “Instead of such synthetic liners, a compacted clay liner was used over the bottom and slopes of the

Lack of Operation Monitoring and Maintenance Of the Turkish wetlands studied by Gokalp et al (2014), none had a proper maintenance and operation plan and little to no maintenance was actually undertaken. This led to avoidable problems such as inlet and outlet blockages, non-uniform (inconsistent) reed plant growth, slope erosion/ damage and effluent flows being non uniform.

References

1. Albold A, Wendland C, Mihaylova B, Ergunsel A, Galt H. “Constructed Wetlands, Sustainable wastewater treatment for rural and peri-urban communities in Bulgaria”WECF, 2011. 2. Tilley E, Luethi, C, Morel, A, Zurgruegg, C, Schertenleib, R. (2008): Compendium of Sanitation Systems and Technologies. Duebendorf, Switzerland: Swiss Federal Institute of Aquatic Science and Technology (EAWAG) Water Supply and Sanitation Collaborative Council (WSSCC). 3. Hoffman H, Platzer C, Winker M, Muench E. “Technology review of constructed wetlands subsurface flow constructed wetlands for greywater and domestic wastewater treatment, 2011. 4. Ayesha J, “Wastewater treatment in flood affected areas using constructed wetlands Nowshera, Pakistan” 5. Gokalp Z, Uzun O., Calis Y., “Common failures of the natural wastewater treatment systems (Constructed wetlands) of Kayseri, Turkey, Ekoloji23, 92, 38-44, 2014. 6. Kimwaga R, Mwegoha W., Mahenge A., Nyomora A., Lugali L., “Factors for success and failures of constructed wetlands in the sanitation service chains”, 2013 7. Gjinali E, Niklas J, Smid, H. Wastewater treatment using constructed wetlands Tirana, Abania. Sustainable Sanitation Alliance, 2012. 8. Waste water gardens information sheet, “Constructed wetlands to treat wastewater” 2015.

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A Research Agenda for Smart Infrastructure in South Africa

Pravesh Debba & Chris Rust


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T

here is no doubt that infrastructure and the built environment are crucial to the development of and poverty alleviation in South Africa. This is emphasized in a number of official documents including the MTSF (2009), the Diagnostic Overview (National Planning Commission 2010), the National Development Plan (National Planning Commission 2012) and the National Infrastructure Plan (2012). Of particular importance is also the current role of the Strategic Infrastructure Projects (SIPs) that are funded from a number of existing budget items in various government departments and co-ordinated by the Presidential Infrastructure Coordinating Committee (PICC). Current levels of funding are in the order of R813 billion (public funding only) into infrastructure such as roads, energy generation plants, water infrastructure and public buildings over the next three years. Price Waterhouse Coopers estimate that by 2025 global infrastructure spend will double to about US$9 trillion per annum (PWC, 2014). However, the South African Institute of Civil Engineers (SAICE) reported in the Infrastructure Report Card 2011 (Amod et al, 2012) that serious problems are experienced with South African infrastructure particularly in the areas of health infrastructure, water infrastructure, sanitation, as well as secondary and tertiary roads. These problems are due to a number of factors including insufficient funding to manage, plan and maintain the infrastructure assets; a shortage of skilled resources; and a lack of appropriate technological solutions for the problems experienced with infrastructure planning, materials, design, construction, maintenance and operation. The South African situation is unique due to certain aspects in the character of the built environment, for instance, the apartheid legacy, our specific conditions in terms of climate, geographical location, and geology; as well as the availability and nature of materials. This implies that foreign technologies and solutions for infrastructure cannot always be applied directly to solve our problems. In most

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cases they have to be modified and often new technologies have to be developed to suit our specific conditions and needs. Therefore, the South African built environment needs unique South African solutions to suit our problems and needs. As indicated above, government has announced plans to invest R813bn into infrastructure in the next three years. However, this is not new funding, but rather the total funding by all levels of government budgeted and leveraged. A large proportion of this is coordinated by the PICC through the SIPs. Figure 1 shows the planned spend on infrastructure in a number of categories (Department of Finance, 2015).

Figure 1: Planned Government spend on infrastructure 2015/16-2018/19

In spite of the investment by government in these sectors, the built environment sector is in decline at the moment as is clearly indicated by the drop in share price of major companies (as much as 60%), drop in margins in the construction industry from to , and the drop in the construction industry confidence index from to (2015 Figures). Some of this is due to the slow pace at which government is spending the planned funding, with, in many instances, budgeted funding remaining unspent. This research aims to address the current and future challenges in the built environment and to identify technological development that may be required for smart infrastructure in South Africa. The chapter describes the process of developing a research agenda for smart

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infrastructure in South Africa. This was achieved through several stakeholder workshops and the development of three technology road maps for smart infrastructure, and the subsequent development of a list of research focus areas for the Council of Scientific and Industrial Research (CSIR) in South Africa. Challenges in the built environment There are many challenges facing the built environment sector. The challenges are broad, from institutional issues such as a lack of capacity, fraud and inefficient policy and legislation, to technological shortcomings and financial governance. These problems are particularly severe at municipal level and in some provinces. Many of these challenges are outside of the scope of this document, however a number of “Grand Challenges” have been defined (CSIR, 2015) that relate to built environment infrastructure and its operation. These are (depicted in Figure 2): Lack of adequate infrastructure for efficient service delivery: Infrastructure plays a major role in delivery of health services, education, and municipal services such as water and sanitation, access roads, and housing. Currently the levels of service delivery in South Africa in this regard are well below par and subsequently leading to service delivery protests. According to the Diagnostic Overview (ibid), South Africa still faces significant backlogs in social infrastructure. Ageing and crumbling infrastructure: A significant portion of South Africa’s infrastructure is old and in many instances crumbling, particularly at municipal level (waste water treatment plants and roads for example). SANRAL indicates that more than 40% of the country’s roads are older than their design life. This has been emphasized by the South African Institute for Civil Engineering (SAICE) and in the NPC Diagnostic Overview (ibid).

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Urbanisation and growth of cities: It is estimated that by 2030 more than 70% of South Africa’s people will live in cities. This places major pressure on the infrastructure in these cities and also leads to unorganised development of cities and informal settlements. There is a need for improved spatial planning and integrated planning of infrastructure investment. Lack of sufficient and effective water infrastructure: South Africa is defined as a water scarce country, as mentioned in the Diagnostic Overview (ibid). Both water availability and water quality are major challenges, particularly due to climate change and municipal pollution (sewage disposal), industrial effluent, acid mine drainage and salinisation caused by irrigation. More than 10% of South Africans still do not have access to potable water. Water infrastructure in South Africa is rated of poor quality by SAICE (Amod et al ibid), particularly waste water treatment systems and, in some cases, water reticulation leading to major losses and water quality problems. Sub-optimal performance of economic infrastructure system: It is well known that infrastructure boosts economic growth. Government has set targets for infrastructure spend of 25% of GDP. However, according to the Diagnostic Overview, South Africa has a “legacy of old, outdated and unreliable infrastructure” and it specifically mentions transport infrastructure (road, rail, por ts, and airports) and water infrastructure. In many instances maintenance of infrastructure is a significant problem. Effect of climate change Climate change affects the performance of infrastructure greatly due to the fact that infrastructure is designed to last for 20 to


6 50 years. Particularly where flooding, rising sea levels and increased temperatures are concerned. Ports are particularly prone to problems associated with rising sea levels and buildings and roads are susceptible to increased temperature levels and precipitation. Institutional weakness, lack of capacity and funding constraints: The Treasury Capacity Building Report (Treasury 2015) states that: “Within government, systems are chaotic, often impeding delivery. There is a lack of integration between human resource development and strategic and operational planning functions. Management capacity at all levels is a significant problem and this has a key impact on performance.” This is particularly true in the infrastructure field with many of the built environment professions being on the national scarce skills list. In tough economic times there are also severe funding constraints associated with infrastructure investment. The R&D challenges are to develop the planning processes and technologies, design methods, materials, construction methods and maintenance techniques that will address the above in a cost-effective way, yet provide high quality infrastructure. Climate change

Ageing infrastructure Lack of service delivery Social infrastructure

Impact of urbanisation Water scarcity and lack of water infrastructure

Economic infrastructure

Sub-optimal performance of economic infrastructure

Lack of institutional capacity

Figure 2: Summary of grand challenges and their imteraction with social and economic infrastructure

Some current responses to these challenges include: • Service delivery and infrastructure

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• Architectural design of buildings such as health facilities and schools, technologies for rural water provision, improved sanitation and waste water treatment facilities, improved access roads, and public transport modelling and design. • Ageing and crumbling infrastructure • New design methods and processes, maintenance methods, new materials, new management methods • Urbanisation and growth of cities • Urban modelling and planning technologies, remote sensing technologies, human settlement design, smart infrastructure solutions • Water scarcity • Water network modelling, re-use of water, AMD treatment, waste water treatment • Sub-optimal performance of economic infrastructure system • Design methods, materials, construction methods and operational processes for high volume roads, ports, airports and railways • Climate change • Development of design methods and materials that are climate change resilient, particularly heat, water and weather resistant infrastructure • Institutional capacity • Training, technology transfer, institutional support • Decision support systems such as road and bridge asset management systems, maintenance methods and procedures In addition, the CSIR recently completed a project to investigate Smart Infrastructure and how it could be harnessed to address challenges faced by the South African built environment. During the project a series of Road Maps were drawn up, through workshops combining relevant stakeholders and senior researchers from CSIR, to provide a unified view on the future role of Smart Infrastructure. This chapter summarises some of the findings from that project (as it relates to roads

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and transport systems; buildings and water infrastructure), but first provides background on Smart Infrastructure and Road Maps. What is Smart Infrastructure? The Royal Academy of Engineering (2012) defines Smart Infrastructure as a system that uses a feedback loop of data as evidence for informed decision-making. The system can monitor, measure, analyse, communicate and act, based on information captured. Different levels of smart systems exist. A smart infrastructure system may: collect usage and performance data to help future designers to produce the next, more efficient version; collect data, process them and present information to help a human operator to take decisions (for example, traffic systems that detect congestion and inform drivers); and use collected data to take action without human intervention. For this research, we have chosen to define Smart Infrastructure as addressing the three pillars indicated in Figure 3 below. It can be noted that, apart from smart systems with feedback loops, we have also included smart materials and smart processes.

This implies that a layer of technologies may be used that can be embedded in the design of new infrastructure or applied to existing infrastructure. Smart infrastructure technologies can apply to a system wide application, for example the development of smart electricity grids. It can also be targeted at a specific element within the infrastructure chain, for example the use of sensors to detect the performance of a bridge or road under high volume traffic conditions. The ability to apply technology to infrastructure assets has existed for some time. However, rapid advancements in sensor, communications and analytical technologies mean that smart infrastructure is a relatively new phenomenon. Research, development and deployment of smart technologies are ongoing in a wide range of infrastructure. Across the world policymakers, infrastructure providers, researchers and enterprises are working to develop solutions that use advanced technologies to address infrastructure challenges in more efficient ways. It is not surprising, however, that infrastructure solutions usually emerge in response to a particular issue or deficit faced by a country or region. For example, faced with crippling congestion, Singapore has become a world leader in intelligent transport systems. Objectives and methodology Objectives of the study

Figure 3: The three pillars of the CSIR Smart Infrastructure programme

According to Forfás (2011) in Ireland “Intelligent Infrastructure” or “Smart Infrastructure” is the application of technology to deliver a more effective and efficient infrastructure service.

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An objective of the project was to develop technology road maps for the Roads and Transport; Buildings and Water Infrastructure domain area within the infrastructure sector. Each of these three road maps would then be used to determine specific focus areas for future Research and Development activity to meet the challenges identified in the Roads and Transport, Buildings and Water Infrastructure Sectors in South Africa. Methodologies used


6 Literature reviews were carried out to assess the state of knowledge and activity in smart roads, smart transport systems, smart technologies in buildings, smart water networks, smart technologies in ports, smart cities, smart sensors for infrastructure and the use of systems thinking in smart infrastructure, both locally and internationally. Thereafter, the road mapping methodology developed by Professor Robert Phaal (Phaal et al, 2004) from the Cambridge University was used. This method consists of two stages: the development of a strategic plan (the S-plan) followed by the development of a Technology plan (the T-plan). These two plans attempt to link current and future envisaged challenges and drivers in a specific sector or business to current and future technology trends. The Technology maps developed in this way can then be used as input into the identification and prioritization of the R&D focus areas required to address the challenges. A schematic of the final product is shown in Figure 4 below.

Figure 4: The three layers of the technology road map

In this way, key solutions are defined by analysis of the perceived current and future drivers and challenges in the sector. The current and future capabilities required are in turn defined by the key solutions required to address the drivers and other challenges. Phaal (ibid) indicates that Technology roadmaps have great potential for supporting the development and implementation of

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integrated strategic business, product and technology plans, provided that the information, processes and tools to produce them are available. Road maps and the road mapping process can provide a means for enhancing a sector’s ‘radar’, in terms of extending planning horizons, together with identifying and assessing possible threats and opportunities in the sector. For example, road maps can be used as a means for assessing the impact of potentially disruptive technologies and markets on a sector. The work done during the literature reviews were used in two ways: • To provide some ‘seed’ ideas on the road map to stimulate discussion during the workshops, and • To augment the outcome of the workshops to finalise the road maps. Typically the workshop participants were requested to provide quick ‘top of the head’ individual inputs on ‘stickits’ that were then displayed on a large road map on the wall. They were then divided into groups to analyse these and consolidate the individual ideas into drivers, or in the second series of workshops, key solutions and technologies. This output was then compiled into the first order road maps for analysis and augmentation with desk top findings. Four workshops were conducted, each attended by delegates from industry and CSIR: • A strategic workshop to determine the drivers, challenges and trends in the Infrastructure Sector. • A Roads and Transport T-Plan workshop to determine the key solutions required to address the challenges as well as the technologies required to build the key solutions for roads and transport. • A Buildings T-Plan workshop to determine the key solutions required to address the challenges as well as the technologies required to build the key solutions for futures and smart buildings. • A Smart Water Infrastructure T-Plan workshop to determine the key solutions

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required to address the challenges as well as the technologies required to build the key solutions for smart water networks and water infrastructure. Findings from the literature review Smart Roads (George and Verhaeghe, 2015) The workshops focused on both “smart” road infrastructure technologies as well as the related transportation systems, and discussions of issues affecting both the infrastructure as well as the transportation, management and decision support systems required to operate and use the infrastructure. The world’s road network has developed over thousands of years, from the track to the paved road, then to the motorway. With each new generation of road networks, passenger comfort, improved speed, reduced vehicle damage and continuous travel between commercial and population centres have been dramatically improved. However, modern challenges (including climate change, greater traffic volumes and demand for minimal disruption to road users) necessitate the introduction of a fifth generation road that is revolutionary and innovative and better suited for the 21st century. In this regard, the Forever Open Road programme (TRL 2016) aims to create a road that is adaptable, automated and climate change resilient, based upon a concept for building and maintaining roads that can be applied to all road types, regardless of region or country. The Forever Open Road programme forms the flagship research programme of the Forum of European Highway Research Laboratories (FEHRL), who is in collaboration with a number of ‘sister’ national programs with shared objectives. The sister programmes include the “Route 5ème Génération – R5G” (5th Generation of Roads, France), “Straße im 21. Jahrhundert” (Road in the 21st Century, Germany), the Coastal Highway Route E39 (Norway) and the Exploratory Advanced Research (EAR) Program (USA). It

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is envisaged that there will be knowledge sharing between these programs as well as the sharing of research expertise, test facilities and demonstrators. The report describes technology trials that support the Forever Open Road concept as well as the demonstration of road maps which illustrates the roll-out process for large-scale demonstration projects and defines how the fifth generation road will function and transform the way roads are built, designed, maintained and operated. Some of the technical solutions that are addressed in the Forever Open Roads Programme are: • Adaptable Roads • Solar Roadways • Self-Healing Concrete • Self-Cleaning Materials • Durable Asphalt Pavements • Harvesting Solar Energy • Plastic Roads • Bio-Asphalt from Microalgae • Self-Healing Porous Asphalt Pavements • The RollPave System • Modieslab • The Super-Slab System • Precast Pre-Stressed Concrete Pavements • Automated Roads • Vehicle to Vehicle and Vehicle to Infrastructure Technology Systems • Driver Assist Systems • Curve Speed Warning Application • STOP Sign Gap Assistance • High Occupancy Vehicle (HOV) Lanes • CITS (Copenhagen Intelligent Transport Systems) • ERA-RB system • Climate Resilient Roads • “Weather-Indicating” Roads • Temperature Sensors Buildings (Mphahlele, 2015) The literature review conducted on buildings identified a number of international trends in smart buildings, as discussed below.


6 Sustainability The emerging trend with respect to sustainability is for the built environment to move towards energy savings. The aim is to have a built environment that has very low carbon emissions. It is important, however, to note that sustainability is not entirely about green building. Green building is a topic which dominates the “sustainability” conversation. The CIB defines sustainability as follows (CIB, 2010): “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs” The various visions described in section 2.1 outline the following interventions with respect to sustainability: The CIB recommends moving towards “Smart Eco-Buildings”. This includes interventions such as education for industry stakeholders and users, designing flexible buildings and co-ordinated policy making efforts. Vision 2025 suggests that in order to attain an industry that leads in low carbon and green construction exports, the country must revisit the entire building process. Interventions such as improved procurement and job opportunities aimed at driving out carbon from the built environment must be implemented (HM Government, 2013). The United Nations Environment (UNEP) presents a summary for decision makers on how reductions of gas emissions in buildings can be realised. They propose that, on a technical level, emissions must be assessed throughout the lifecycle of the building, developing solid energy performance requirements and indicators, collecting data and information about the size and characteristics of the building industry, building capacity to implement energy efficiency measures. Integration The various visions propose, by and large, that in order to move the construction industry forward and create ‘smarter’ buildings, there needs to be a greater effort with respect to integration. The integration suggested by

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European countries’ and UK publications involves areas such as digitization of building processes through the implementation of Integrated Design & Delivery Solutions (IDDS) (CIB 2009) such as Virtual Design (VD), 4D CAD and Building Information Modelling (BIM). The use of digital integration platforms and technologies speaks to addressing secondary concerns about the fragmented nature of the industry’s role players and supply chain. It is envisioned that these integration methods will improve the current status. Currently the plan in the UK is to have BIM implemented in all centrally procured contracts by the year 2016. However, BIM, 4D CAD and VDC are all design interventions, and the CIB recognises that integration across all construction phases needs to be implemented. Building Methods/Processes Building methods and processes not only affect the actual construction of the designed buildings but also ultimately impacts on the life cycle. It is important to take building processes and methods into consideration at the inception of the project. The following are topics covered in the “visions” documents with respect to building methods and processes: Retrofitting Huge savings can be made from retrofitting buildings to fit the current needs of users and possibly those of future users. The idea is to ensure that buildings are designed to be more flexible. Building Processes Building processes for new buildings should aim for just-in-time delivery. This project delivery method is consistent with lean construction methods and has benefits such as less incidents, improved productivity and better quality (McGraw Hill Construction, 2013). It is proposed that a “whole life thinking” approach be attached to such processes. This includes the

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in-use performance of systems, components and the actual structure. When considering the whole life cycle of the building, an assessment of constructability must be undertaken, where the proposed building processes is reviewed in order to reduce or prevent delays to the project. The analysis also allows for construction knowledge to be applied at an early stage where it will have long standing effects on the entire life cycle. The recommendation is also that building interventions taken at the inception of the project be made readily available and the performance of such interventions be measured physically throughout the life stages of the project. Currently, the practice is to have an estimate of life cycle performance which is undertaken through the employment of various modelling software. Offsite Construction Offsite construction is in line with the lean construction mentality, where the aims are to reduce time spent on site and the quality of the end product. The industrialisation of buildings will also make it easier to implement monitoring technologies for life cycle assessment purposes and improve the overall quality of the buildings as component manufacture takes place in a controlled environment. Another added benefit of offsite construction is the ease of which integrated technologies, as proposed by CABA, can be implemented. Materials The vision for materials used in buildings is viewed by built environment research institutions across the first world to be moving towards sustainability and independent reporting. The idea is to implement materials that have self-recording mechanisms such as RFID chips. These RFID chips will provide a building componentâ&#x20AC;&#x2122;s history and current status in terms of maintenance requirements and structural strain. The RFID chips will also

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go a long way in providing user comfort information that can be used to plan better for various health care activities (European Construction Technology Platform, 2005). In the UK, materials are also seen to be getting lighter, stronger and lasting longer through the use of nanotechnology. Nanotechnology is the manipulation of materials at an atomic level in order to alter its properties. The vision is that UK building users in the year 2020 will experience clean, durable responsive and an environmentally friendly environment (CRISP/ SPRU, 2003). The reduction of environmental impact of building material production and demolition is also an important consideration. The idea is to select or develop materials that are environmentally friendly during the production stage, usage and ultimately the demolition stage. Recommendations such as the use of dismountable building components as opposed to dismountable components, the creation of performance indicators, performance rating systems, and the development of new life cycle design concepts and building component have been put forward. Smart water networks (Zulu et al, 2015) Present days water systems are under increasing demand. Water utilities are relying on water infrastructure that is aging and deteriorating to meet growing demand, tough environmental targets, and increasing regulatory requirements. While at the same time these utilities are required to decrease non-revenue water losses and increase their operational efficiency. Water networks are vast and comprise a variety of components (pipe segments, pumps, valves, etc.) and all these components differ in age, design and material type. The performance and efficiency of these components decrease with their age, making them susceptible to failures and leaks. The extent of water networks renders them difficult to access and this adds to the


6 complexity for municipalities to keep track of their assets, or even be aware of any leaks in the systems. Smart Water Network technologies are a collection of data-driven components helping to operate the physical layer of pipes, pumps, reservoirs and valves. These smart water networks have an important role to play in addressing the current challenges experienced. They are also an essential part of the transition of the water industry to a data-centric business that is able to capitalize on the benefits of intelligent devices, IT, and communications networks. The introduction of smart water network technologies is part of the long-term transformation of the water industry. Intelligent devices, communications networks, and advanced IT systems are helping the industry face the challenges posed by rising costs of operations, global urbanization, climate change, and other pressures on supply and distribution. In the process, the industry will become increasingly information-focused, drawing on real-time data from the pumping station to the meter. An integrated view of all the elements of the water network will enable better management of water and energy resources, reduce leakages, and improve customer service (Britton et al, 2013), (Joseph, 2004). Despite these challenges, a steady ramping up of smart water network deployments over the next decade and beyond is expected. Adoption will be an evolutionary process and not a revolutionary process. Growth will be steady rather than spectacular, but the gains will be impressive and will gradually win over even the most cautious of utilities and regulators. Smart water networks must draw from a wide spectrum of technologies in order to successfully provide smart solutions

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to utilities. The five layers of required technologies are shown in Figure 5 below.

Figure 5: Elements of a smart water network

Some of the technologies used include: • Smart meters; • Automated meter reading (AMR) • Automated meter management (AMM) • Interval metering with automated meter management (AMM-IM) • Prepayment meters (PPM) • Advanced metering infrastructure (AMI) • Real time communication networks • Advanced data management systems • Real-time data analytics and modelling • Automation and control tools New focus areas and research themes identified for Smart Infrastructure After the literature reviews were carried out, the workshops were held and first-order Technology Road Maps were drawn up. These road maps helped to pinpoint a number of new research themes and focus areas which could in future be investigated. Roads Adaptable roads The Adaptable Road shows potential to provide a quick and cost effective method of designing, constructing and maintaining roads (TRL, 2015). Such roads will be based on pre-fabricated/ modular systems that can be implemented on any road type. It will also adapt to increasing travel capacities and road user demands including changes in demand for public transport, cycling and walking. In addition, the adaptable road will harvest, store and use solar energy, power electric cars and will also be able to clean and repair itself.

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Figure 6: Schematic of the Adaptable Road (from the European Forever Roads programme)

The following potential focus areas for CSIR research were identified for further consideration: • Materials for advanced road construction with a particular focus on nanotechnology to enhance engineering properties and weather resistance; • New design and construction systems such as modular blocks from advanced materials; • Advanced, robotic maintenance systems; • The use of solar power in adaptable roads. The Automated Road The Automated Road will integrate road side intelligence with ICT applications in the vehicle, the services and the operator. The automated road will include a completely integrated data, observing and control framework; interacting between road users, vehicles and road administrators. It will bolster a compliant vehicle-road framework that will manage travel demand and traffic movements. In addition it will measure, report and react to its own condition, giving real-time data on climate, occurrences and travel data.

The following potential focus areas for CSIR research were identified: • Comprehensive, interoperable communications systems linking road, driver, vehicle and the operator; • Integrated traffic control, monitoring of traffic and road conditions to improve reliability and efficiency; • Incident monitoring and automated response systems to reduce delays. The resilient road The resilient road will focus on ensuring that service levels are maintained under extreme weather conditions and climate change. In South Africa this implies resilience to incidences of heavy rain as well as very high road surface temperatures. A schematic of the European Resilient Road is shown in Figure 8.

Figure 8: Schematic of the Resilient Road (from the European Forever Roads programme)

The following potential focus areas for CSIR research could be considered: Cost effective materials that can withstand very high road surface temperatures; The protection of granular road materials against excessive moisture using nano-technology.

Figure 7: Schematic of the Automated Road (from the European Forever Roads programme)

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Advanced design systems for roads The following research topics could be considered: • Advanced, web-based, calibrated SA Road Pavement design system, incorporating real time information;


6 • Design methods for labour intensive construction and to create jobs through off site manufacturing of road elements Advanced data management and maintenance The following potential research topics could be considered: • Real time, web-based asset management systems that include life cycle management; • Integrated real time systems and performance prediction models for advanced maintenance of infrastructure. Transport The workshops identified a number of themes for research into advanced transport. Apart from the Automated Road solutions discussed above, additional focus areas for potential future R&D are listed below. User interaction with the transport system This includes: • Real time data distribution through for example smart phone technology allowing personal travel decisions; • An integrated public transport management control centre with real time data and information. • Transport systems design • This includes: • Advanced self-regulation, monitoring and control of freight operators; • Advanced vehicle tagging, monitoring and control to supply real time information to transport systems design and decision making; • Advanced funding models for infrastructure and public transport. Buildings (Mphahlele, 2015) Passive buildings Passive buildings are buildings that make use of passive technologies as well as planning and design strategies to enhance building performance. Technologies and strategies that support passive buildings include smart siting and orientation; smart glazing sizing

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and location; high efficiency windows; high-efficiency insulation; smart shading; high-performance building envelopes (roof assembly, superstructure, and sub-structure); Trombe walls; off-grid water harvesting; solar electricity generation systems (energy generation, water heating); and natural ventilation systems including displacement ventilation. Figure 9 illustrates some of these principles.

Figure 9: Passive building design

The following focus areas for CSIR research should be considered: • M a te r i a l s fo r h i g h p e r fo r m a n c e building envelopes with par ticular focus on green materials and phasechange materials; • Climate-responsive decision support tools to optimise building envelope performance; • Developing design strategies and technologies for advanced envelope components and systems; • A s s e s s i n g t h e p e r f o r m a n c e o f advanced envelope components and systems, both seasonally and across varied climatic zones; • Analysing and optimizing a continuum of centralized and personal control o p t i o n s fo r a d v a n c e d e nve l o p e systems; • Sustainable Urban Drainage Systems (SUDS) including effective utilization, treatment, infiltration and storage;

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• Filling gaps that are essential in understanding indoor chemical pollutants; and • Developing metrics and protocols for assessing the individual and combined e f fe c t s o f i n d o o r e nv i ro n m e n t a l conditions. Active buildings Ac tive buildings are buildings that make use of active technologies as well as planning and design strategies to enhance building per formance. Examples include a dynamic building envelope that exploits and integrates advances in materials science and heat, air and ventilation control with building envelope engineering to suppor t the d e ve l o p m e n t a n d i m p ro ve m e n t o f existing technologies which can lower heating and cooling demands and collect renewable energy. Anticipated new and improved technologies include vacuum and advanced insulation for wall and roofing systems; façade-engineered curtain walls with sensors, high-thermal re s i s t a n c e a n d d y n a m i c s o l a r l o a d control; and advanced roofing systems w i t h u l t r a - h i g h t h e r m a l re s i s t a n c e and integrated photovoltaic material. Technologies and strategies that support a c t i ve b u i l d i n g s i n c l u d e a d a p t a b l e high-per formance building sk ins; multi-layered envelope and active solar systems; communications net wor ks; sensors and ac tuators; and building systems (energy use, environmental control, communications, security and a c c e s s c o n t ro l, l i fe - s a fe t y s y s te m s, monitoring and maintenance, lifts and escalators). Figure 10: Henning Larsen Syddansk University Communications and Design Building 2

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The following focus areas for CSIR research should be considered: • Adaptable, dynamic, multi-layered, active building skins; • Smart grids (vertical and horizontal integration); • Development and testing of integrated water management systems including blue, green, grey and black water; • Development of materials that are self-maintaining, self-healing and self-diagnosing; • Buildings planning and design; • Building assessment; and • Building management. Construction processes Smart buildings rely on smart construction processes. Processes that support smart construction include offsite construction; modular building; integrated design and delivery systems (IDDS); Virtual Design ( VD); and 4D CAD and Building Information Modelling (BIM). The following focus areas for CSIR research should be considered: • IDDS; • BIM; • To o l s fo r d e s i gn , d e l i ve r y a n d operations;


6 • Building materials, components and assemblies; • Metrics, benchmarks and databases; • Offsite manufactured construction; • Whole life thinking; • Lean construction; • Life cycle analysis; • Rapidly relocatable structures; • Policy analysis and development; and • Standards, codes and rating systems. Retrofitting Buildings are designed for a long-life; however, unlike other infrastructure such as aircraft, they are not retrofitted with the latest technologies. Smart buildings are designed to be more flexible over their life cycle with interchangeable and replaceable components. Existing buildings require upgrading to ‘smart’ status over time. The following focus areas for CSIR research should be considered: • Passive technology retrofitting; • Active technology retrofitting; • BIM performance optimisation; • Retrofitting with interchangeable and replaceable components.

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• Use of nanotechnology material in water treatment plants to enhance surface area of reactants leading to more effective treatment • Real time leak detection systems • Robotics for repairing water pipes • Desalination technologies to augment fresh water supply • The driving factor is the reduction of water losses due to leakages in the distribution network. Wastewater Treatment Infrastructure • Design/reconfiguration of Wastewater Treatment plants ( WWTP) to incorporate renewable energy use aspect which will lead to energy savings, e.g. optimization of biogas production stage using bio-digesters • Incorporation of real time effluent quality monitoring systems at each critical stage of the wastewater treatment plant • I mproved waste water treatment processes including biological treatment systems

Water infrastructure Current water infrastructure problems and potential development areas have been identified through the workshops. These will be used as the basis for research leading to smart water infrastructure. Smart Water Supply Infrastructure • Water Distribution Network designs with IC T feedback systems that will make the infrastructure operation and maintenance easier. • Design and optimization Real Time Dynamic Hydraulic Models with fault diagnostic capabilities e.g. abnormal pressure detection and correction.

Figure 11: Schematic Diagram of a WWTP showing biogas production and electricity generation as well as the stages where real time monitoring systems can be incorporated.

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The real time effluent quality monitoring idea will be incorporated in other type of wastewater treatment processes such as industrial wastewater as well as AMD. Swarm Robotics for port engineering (Hlabela et al, 2016) In some cases UAV’s (Aerial drones) and ASV (Autonomous Survey Vehicles) can be used together to provide scans below and above water. One such case is when breakwater monitoring is conducted, as scans of the breakwater above water and below water is needed. A diagram of such integrations is shown in Figure 12 on the next page.

Figure 12: Schematic of the use of swarm robotics

The previous page illustrated how the drones would operate and store data from the port. The integration of the ASV and AUV is known as swarm robotics. The port engineer can choose to operate them

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separately or let the one follow the other to endure data is fused correctly. The data collected would be sent and stored wirelessly at the CSIR’s SADCO database where both port engineers and authorized CSIR researchers have access to the data. During a deployment the results are sent to the port engineer and to port control. Port control would need the latest scans of the bathymetry to advise the pilots of the vessels entering the port of the safe and danger areas of the port. Decision Support Systems for Smart Infrastructure Background During the work sessions for Smart infrastructure, the terms “Decision Support” and “Decision Support Systems” came up repeatedly as a cross-cutting need. Although the focus or expressed needs differed slightly between the roads, buildings and water domains, a number of aspects were mentioned in terms of decision support needs: • Vertical integration problems: There is often a mismatch between the decisions taken by managers at a strategic level and the problems experienced by operational staff – a particular example that was mentioned in the Water work session that operational staff expressed the opinion that “we know where the real problems are, but management don’t address these”. It may just be a perception due to communication issues between management and operational staff, but it could also mean that operational data are not always included correctly in strategic decision-making. • A need to incorporate forecasts / trends in high-level planning: In a number of workshops the perception was expressed that planning often does not make sufficient allowance for future needs. • A greater need for monitoring, especially real-time monitoring, as part of the decision-making process: although this was


6 expressed as a need, the type of monitoring or the type of information that should emanate from such monitoring activities were not clarified during the workshops. Comments in terms of future work As Salet, Bertolini, and Giezen (2012) point out, complex infrastructure construction projects are subjected to large amounts of uncertainty, not just due to complexities within the construction process itself, but also due to the fact that the environment in which the infrastructure is placed may change over the time of construction. For example, when a large road or railway line construction project is planned, the planning takes into account certain connectivity needs, but since the actual construction can take up a number of years, the connectivity needs may be different at the time of completion of the road or railway line from what it was during the planning stages. The authors argue that his uncertainty needs to be managed in addition to the management of the actual construction process and suggest some ways in which the uncertainties can be handled. How decisions are handled under such conditions of uncertainty is therefore an important question, which is in line with the comments made at the Smart infrastructure workshops. In addition, one may ask what decision support is required and what data should feed into decisions, and how does Smart infrastructure require different and / or more decision support? While Salet, Bertolini and Giezen (2012) discuss the need for planning to be responsive to these uncertain conditions, and to encourage learning throughout the construction process, they stop short of providing a detailed decision-making framework that can be used to implement this, and to align strategic and operational planning. The issue of uncertainty in decision-making and planning is, of course, not limited to (large) infrastructure projects. In particular, within the environmental planning domain, in which planning often has to be done within “open”,

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complex, ever-changing systems, the concept of Adaptive Management (AM) has become widely accepted, especially within planning institutes in the USA and Canada. The principle of accepting that uncertainties may not be resolved at the planning stage, but that it may be advisable to adopt “learning while we are doing” approach is the key underlying principle of an Adaptive Management approach. Many environmental agencies support the adaptive management process and quite a few applications of the approach to planning and decisions can be found in scientific literature. Linkov et al (2006) provide a general decision framework that incorporates adaptive learning principles with stakeholder consultation and supporting modelling and simulation tools, while Torres et al (2010) report on a decision support tool that was developed to implement adaptive management principles. It therefore seems as if the adaptive management approach could be a useful framework to consider when designing a Decision Support System. The AM approach relies heavily on an iterative approach to decisions, as quoted in Failing, Gregory and Higgins (2012). However, Gregory, Failing and Higgins (2006) caution that adaptive management should not be seen by environmental planners as the only way to handle uncertainty – they stress that “AM is not so much a general approach to environmental management as it is a specific management alternative – one of potentially many…” However, they concede that “there is no generally agreed-upon framework for evaluating AM as once of a suite of environmental management alternatives.” They then go on to provide guidelines and considerations to use when deciding when and how to use Adaptive Management. While AM seems to provide a useful framework for dealing with uncertainties plaguing many infrastructure problems, while also allowing for changing decisions based on operational, even real-time, information (as in Torres et al (2010)), it is not immediately

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clear how AM would be applied within the AM approach should be adapted to the “Smart” infrastructure environment. A more in-depth study would need to be done to determine whether an AM framework would provide solutions for the problems raised regarding shortcomings in decision-making in general, and decision support systems, in particular during the workshops. Also, since there is general agreement in the environmental literature that AM is a well-accepted approach but not always implemented, even in conditions where it may be required, care must be taken to develop practical guidelines to guide implementation of AM in an infrastructure context. Specific suggestions for future work In the light of the core role of data and information within Smart Infrastructure, by definition, it would be important to manage the use of data and information correctly within a Smart Infrastructure application, thereby bringing together Smart Infrastructure, Adaptive Management and Decision Support Systems concepts. Certain questions need to be explored, for example: • What is the relationship between strategic decisions and operational needs within Smart infrastructure? • Does Smart infrastructure need different types of information than “traditional” infrastructure? • Is there a need to adapt the existing AM framework to provide for better support to such decisions? • What is the capacity of current DSS software systems to support an AM / revised AM approach? • Can this be illustrated within a specific case study for a “real” beneficiary / collaborator? Conclusion and way forward In summary, through the review of literature on Smart Infrastructure developments worldwide, and through consideration of current and future challenges for infrastructure in

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South Africa, a number of new focus areas research into South African applications for Smart Infrastructure have been identified. These include the following: • The Adaptable Road that will provide a quick and cost effective method of designing, constructing and maintaining roads • The Automated Road will integrate road side intelligence with ICT applications in the vehicle, the services and the operator • The resilient road will focus on ensuring that service levels are maintained under extreme weather conditions and climate change • Advanced road building materials, using in particular nano-technology for example to render granular materials less susceptible to water ingress and to improve the engineering properties of asphalt under extreme weather and loading conditions • Real time, web-based asset management systems that include life cycle management with integrated real time systems and performance prediction models for advanced maintenance of infrastructure and that include advanced vehicle tagging, monitoring and control • Passive building design that make use of passive technologies and planning and design strategies to enhance building performance • Materials for high performance building envelope with particular focus on green materials and phase-change materials • Adaptable, dynamic, multi-layered, active building skins • Advanced building construction processes including processes that support smart construction include offsite construction; modular building; integrated design and delivery systems (IDDS); Virtual Design (VD); and 4D CAD and Building Information Modelling (BIM). • Smart water networks including Water Distribution Network designs with ICT feedback systems that will make the


6 infrastructure operation and maintenance easier; design and optimization Real Time Dynamic Hydraulic Models with fault diagnostic capabilities e.g. abnormal pressure detections and corrections. • Smart waste water treatment system to optimize alternative energy technologies (bio-gas), the use of nanotechnology material in water treatment plants to enhance surface area of reactants leading to more effective treatment, and biotechnology for waste water treatment

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• Swarm robotics for port breakwater surveys • The use of Adaptive Management (AM) principles in the design of Decision Support Systems (DSSs) suitable for Smart Infrastructure applications. Future work will focus on the development of these ideas into a set of project proposals/ programmes through workshopping with stakeholder groups to be presented to the relevant authorities for funding.

References

• Amod S, K Wall and FC Rust. (2012). SAICE’s report cards on the state of infrastructure. Source: Proceedings of the ICE – Management, Procurement and Law, Volume 165, Issue 2, 01 May 2012 , pages 119 –127 • Britton, T.C., Stewart, R.A. and O’Halloran, K.R. (2013). Smart metering: enabler for rapid and effective post meter leakage identification and water loss management. Journal of Cleaner Production, 54, pp. 166-176. • CIB (2009). IDDS “Integrated Design and Delivery Solutions” , CIB Publication 328, Rotterdam, Netherlands • CIB (2010). Towards Sustainable and Smart-Eco Buildings, CIB Publication 332. • CRISP/SPRU (2003). The Emperor’s New Coating: New Dimensions for the Built Environment: The Nanotechnology Revolution, CSRISP, London. • CSIR (2015). Built Environment Strategic Plan 2016/17 – 2019/20, October 2015. • Department of Finance (2015). South African Minister of Finance Budget Speech, February 2015. • European Construction Technology Platform (2005), Vision 2030 & Strategic Research Agenda Focus Area Materials • Failing, L., Gregory, R, Higgins, P. (2013). Science, uncertainty and values in ecological restoration: A case study in structured decision-making and adaptive management • Forfás (2011). Intelligent Infrastructure: Delivering the Competitiveness Benefits and EnterpriseOpportunities. Forfás, Dublin. • George T, and B Verhaeghe. (2015). Final report: The Fifth Generatio Road. CSIR Internal Report, September 2015. • Gregory, R., Failing, L. Higgins, P (2006). Adaptive management and environmental decision-making: A case study application to water use planning, Ecological economics, Vol 58, pp 434-447

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• • • •

• • • • • • • • • • • • • •

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Hlabela P, J Harribhai and M Seboqa. Smart Ports Project Report. CSIR Internal Report, March 2016. HM Government (2013), Industrial Strategy: government and industry in partnership 2025 Joseph, D. (2004). Conserve water with conductivity meters. Metal Finishing, 102(11), pp. 6-11. Linkov, I. Satterstrom, F.K., Kiker, G., Batchelor, C., Bridges, T., Ferguson, E. (2006). From comparative risk assessment to multi-criteria decision analysis and adaptive management: recent developments and applications, Environment International, Vol 32, pp 1072-1093 McGraw Hill Construction (2013), Lean Construction: Leveraging Collaboration and Advanced Practices to Increase Project Efficiency Mphajlele, C. Smart buildings project report. CSIR Internal Report, October 2015. MTSF (2009). Medium Term Strategic Framework 2009. Treasury, South Africa. National Planning Commission (2012). National Development Plan: Vision for 2030. National Planning Commission, South Africa. National Infrastructure Plan (2012). South African Government. National Planning Commission (2010). South African Diagnostic Overview, the Presidency, South Africa. Phaal, Robert, Clare J.P. Farrukh and David R, Probert (2004). Technology roadmapping—A planning framework for evolution and revolution. Technological Forecasting & Social Change 71 pp 5–26 PWC (2014). Capital project and infrastructure spending Outlook to 2025. Price Waterhouse Coopers, New Zealand. Royal Academy of Engineering (2012). Smart infrastructure: the future. London. Salet, W., Bertolini, L., Giezen, M (2012). Complexity and Uncertainty: Problem or Asset in Decision Making of Mega Infrastructure Projects?, International Journal of Urban and Regional Research. Torres, J.M., Mascarell, A.H., Hernandez, J.M.C., Monerris, M.M., Molina, R. (2010). Decision support system development for adaptive management of desalination plant outfalls in marine ecosystems Treasury (2015) http://www.treasury.gov.za/publications/other/devco-op/section_2/01.pdf TRL (20126). http://www.trl.co.uk/solutions/transport-futures/forever-open-road-and-railway/ Zulu, S, S Rajcomar and P Hlabela. Smart water networks Project Report. CSIR Internal Report, March 2015.

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The New Horizon of Innovation

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41 700mm cover width

Klip-Tite™ Similar to Klip-Lok 700™ but with increased wind uplift resistance. The introduction of transverse stiffeners, in lieu of the traditional longitudinal pan stiffeners, form structural members spanning across the width of the pan. The deflection of the pan is thus reduced, increasing the wind uplift resistance of the sheet. These transverse pan stiffeners are a first in the South African sheeting market. Site – rolling is available.

41 406mm cover width

Klip-Lok 406™

Klip-Lok 700™

A concealed fix profile with unique double interlocking side laps makes this a very fast installing roof sheet. This profile is ideally suited to low roof pitches. Manufactured from certified high yield steel or special grade aluminium making it lighter and stronger. Site-rolling is available.

Similar to Klip-Lok 406™ but wider. This sheet is even faster to install yielding greater savings. This profile is ideally suited to low roof pitches. Manufactured from certified high yield steel making it lighter and stronger. Siterolling is available. Klip-Lok 700™ will be phased out and replaced by Klip-Tite™, however it will be available for remedial work at limited capacity.

68 48

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440mm cover width

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Brownbuilt™ This classic and well-known concealed fix sheeting system is available upon request and also for site rolling in neighbouring countries (subject to minimum order quantities). Also frequently used as underslung/ ceiling sheets on fuel station canopies.

Zip-Tek 420

Zip-Tek 440

This unique concealed fix system is commonly known as a standing seam system. This is one of the only concealed fix systems where the sheet can be tapered, as well as curved. It is also the only concealed system that can be reverse curved.

Similar to Zip-Tek 420 but wider, and incorporates transverse stiffener ribs. Please note, Zip-Tek 440 is only available for exports, SADC and African countries.

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Mitigating against the time-of-use tariff by the commercial building sector using a single-axis tracking solar pv array system

Stefan Szewczuk


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T

he Time-of-Use (ToU) tariff is designed to discourage the use of electricity by commercial customers during peak demand periods with the morning peak tariff operating from 7:00am to 10:00am during weekdays. The evening peak demand period with the evening peak tariff is from 6:00pm to 8:00pm. Consequently the ToU tariff encourages large users of electricity to apply their minds as to what demand-side measures they could implement to mitigate against the rising costs of bulk electricity generated by Eskom the South African electricity utility. Renewable energy supply technologies such as those based on exploiting wind and solar resources have shown a steady decline in costs. Figure 1shows the decline in costs and tariffs for large utility scale PV projects in the South African Department of Energyâ&#x20AC;&#x2122;s (DoE) Renewable Energy Independent Power Producer Programme (REIPPP), [online]. The cost and tariffs of PV technology has declined to below coal new build options and has opened new opportunities for the implementation of smaller than utility scale PV projects. These costs have declined to such an extent that PV systems can now be considered as a demand-side measure option and not merely as a mitigation option against load-shedding.

Figure 1. Decline in costs of utility scale REIPPP PV projects, Bischof-Niemz and Roro (2015)

TIME-OF-USE (TOU) TARIFFS Time-of-Use (ToU) metering sets a rate that is dependent on the time of use, and is designed to both recover higher generation cost during peak demand periods, and to encourage users to use less electricity during peak periods. Unlike flat rate

SOLAR PV ARRAY SYSTEM

metering charges a fixed rate per kWh of energy used, irrespective of the time of day or season in which the energy is used. Figures 2 and 3 depicts the principles for ToU tariffs, flat rate tariffs and the solar PV generation curves for a fixed inclination system for summer and winter months, . Features to note are the times during the 24 hour day when off-peak, standard and peak period tariffs are applied. The summer ToU tariff is generally lower than during the winter months when the demand for electricity is greater. The flat rate tariff is constant throughout the year irrespective of the season. Typically the peak tariff is applied in the morning from 7:00am until 10:00am and in the evenings from 6:00pm until 8:00pm. Superimposing the solar generation curve onto the ToU tariffs for both summer and winter provides for options to be considered with regards to demand-side management using PV based systems. During the summer months solar energy has the potential to be utilised from approximately 6:00am in the morning until approximately 6:00pm in the late afternoon. During the winter months solar energy has the potential to be utilised from approximately 7:00am in the morning until 5:00pm in the afternoon.

Figure 2. Summer ToU metering vs solar generation curve

It should be borne in mind that in South Africa the typical commercial environment, the work day is typically from 8:00am until 4:30pm. The question that should be asked and answered is:â&#x20AC;&#x153;Can the added expense of a single-axis

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Together, let’s power a better World. Cat® Thin Film solar photovoltaic technology, backed by First Solar’s Gigawatts of global experience, allows you to affordably and sustainably harness our most abundant energy resource: the sun. For more information on diversifying your energy portfolio, visit www.barloworldpower.com or contact our sales experts on 0860 898 000. © 2016 Caterpillar. All Rights Reserved. CAT, CATERPILLAR, BUILT FOR IT, their respective logos, “Caterpillar Yellow,” the “Power Edge”trade dress as well as corporate and product identity used herein, are trademarks of Caterpillar and may not be used without permission.

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7 tracking system for a PV array be offset by the increased solar based energy that is generated that results in reduction in tariffs paid to bulk electricity supplier?” CASESTUDY: INTEGRATED ENERGY MANAGEMENT FOR A PUBLIC ENTITY The CSIR was commissioned by a public entity to develop an integrated energy management plan to increase its efficient use of energy and reduce its electricity bill. The CSIR was supplied with electricity consumption data for the period from 1 February 2015 until 31 March 2016 to analyse and to develop demand-side options to be considered. The time of use tariffs during the period February 2015 to March 2016 are presented in Table 1. A vast amount of measured data was provided and consisted of the electricity consumption being measured every 15 minutes. Also provided was the monthly maximum demand charge. The ToU tariff and the maximum demand charge to total electricity cost can be derived for each month.

SOLAR PV ARRAY SYSTEM

maximum demand charge is the top speed obtained. Figure 4 depicts in graphical form the ToU tariffs of on-peak, standard and off-peak, during the period from February 2015 through to March 2016.

Figure 4. ToU tariff from February 2015 to March 2016

To reiterate, the public entity’s electricity consumption is measured every 15 minutes resulting in a vast amount of data that is available for analysis. An Excel spreadsheet based methodology was developed to analyse the vast amount of data points. For each 24 hour period a consumption load profile in kWh was established with the ToU tariffs been given different colours to assist in visual analysis: • Green for off-peak tariff • Yellow for standard tariff, and Table 1: ToU tariff used for case study February 2015 until 31 March 2016 to analyse and to develop demand-side options to be considered. The time of use tariffs during the period February 2015 to March 2016 are presented in Table 1. • Red for on-peak tariff Time-of-Use Tariffs from February 2015 to March A vast amount of measured data was provided and consisted of the electricity consumption being measured every 15 2016 minutes. Also provided was the monthly maximum demand charge. The ToU tariff and the maximum demand charge to total electricity cost can be derived for each month. ZAR/kWhr The cost paid in Rand/kwh, including VAT, for the Table 1: ToU tariff used for case study electricity consumed was then superimposed Time-of-Use Tariffs from February 2015 to March 2016 on the consumption profile. Figure 5 shows the ZAR/kWhr Month/year On-peak Standard Off-peak consumption profile in kWh with differing ToU Feb-15 1.06362 0.65322 0.45828 tariffs being represented by the various colours of Mar-15 1.06362 0.65322 0.45828 green, yellow and red for the winter day of 1 July Apr-15 1.06362 0.65322 0.45828 2015. Superimposed is the cost profile in Rand/kWh May-15 1.06362 0.65322 0.45828 including VAT. Each vertical stripe is a consumption Jun-15 3.2034 0.9918 0.53124 Jul-15 3.2034 1.16052 0.61674 value that is measured every 15 minutes. Aug-15

3.2034

1.16052

0.61674

Sep-15

1.22208

0.75468

0.532038

Oct-15

1.22208

0.75468

0.532038

Nov-15

1.22208

0.75468

0.532038

Dec-15

1.22208

0.75468

0.532038

Jan-16

1.22208

0.75468

0.532038

Feb-16

1.22208

0.75468

0.532038

Mar-16

1.22208

0.75468

0.532038

maximum demanddemand charge is the highest averageis demand in kVA during an integrated period in a billing TheThe maximum charge themeasured highest month. As an analogy the ToU charge is the distance covered and the maximum demand charge is the top speed obtained. Figure 4 depicts in graphicalmeasured form the ToU tariffs on-peak,during standard and an off-peak, during the period from February 2015 average demand inof kVA through to March 2016. integrated period in a billing month. As an analogy Figure 5. Electricity consumption and cost profile for the ToU charge is the distance covered and the winter: 1 July 2015

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7 During the off-peak period (green) from 10:00pm in the night until 6:00am in the morning, there is a relatively constant consumption of approximately 450 kWh that is billed ZAR300.00 every 15 minutes. During the standard tariff period the consumption changes according to electricity demand with the associated increase in billing. However during the on-peak periods (red) there is a large spike in billing costs for electricity consumption. The morning peak period is from 7:00am until 10:00am. During this period the maximum electricity consumption is approximately 700kWh that is billed approximately ZAR3000.00 every 15 minutes. Figure 6 shows the consumption profile in kWh with differing ToU tariffs being represented by the various colours of green, yellow and red for the summer day of 1 February 2015. Superimposed is the cost profile in Rand/kWh including VAT. Once again, each vertical stripe is a consumption value that is measured every 15 minutes.

Fig. 6 Electricity consumption and cost profile for summer: 1 February 2016

During the off-peak period (green) from 10:00pm in the night until 6:00am in the morning there is a relatively constant consumption of approximately 400 kWh that is billed ZAR250.00 every 15 minutes. During the standard tariff period the consumption changes according to electricity demand with the associated increase in billing. However during the on-peak periods (red) there is a gradual increase in billing costs for the electricity consumed. Once again, the morning peak period is from 7:00am until 10:00am. During this period the electricity consumption increases steadily from 400 kWh to 700kWh. In harmony with the increase in

SOLAR PV ARRAY SYSTEM

consumption the peak billing increases from ZAR500.00 to ZAR900.00 every 15 minutes. The impact of the winter and summer ToU tariffs is evident from Figure 5 (winter) and Figure 6 (summer). A similar analysis was done for each day during the period 1 February 2015 until 31 March 2016. Integrating the cost curves for each day the daily electricity bill can be calculated. Similarly this can be done on a weekly basis and also on a monthly basis. As stated previously the public entity also provided the maximum demand charge for each month. Adding the monthly ToU charge to the monthly maximum demand charge then provides a total electricity bill for each month. This can be confirmed by analysing the electricity statements for each month. Figure 7 shows the total electricity costs on a monthly basis. The Peak or maximum demand charge is depicted in brown. This Peak or maximum demand charge is relatively constant and hovers around the ZAR500,000.00 per month. The Tariff or integrated monthly ToU costs are depicted in blue. The Peak and the Tariff costs are combined to provide the Total monthly electricity costs as depicted in green. The maximum paid was during the winter month of July 2015 where ZAR2.5million was paid for electricity. The impact of the ToU tariff increases that were introduced on 1 June 2015 become evident when the reduced summer over winter ToU tariff was implemented on 1 September 2015. See Table 1 and Figure 4 for the ToU tariffs.

Fig. 7 Monthly total electricity costs (Base line)

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7

Energy yield and LCOE estimations Based on further analysis using the methodology to procure PV assets at low lifetime costs and using PVSyst software the main results from this analysis is that the public entity: • has an hourly base load of 1500kW • a peak energy demand of 2500kW • during the day hours from 6:00am to 6:00pm an average of ZAR0.90/kWh was paid to the City of Tshwane • the energy consumption profile does match the solar PV generation profile Further analysis was done using a base case of a 500kWp PV array system, one for a fixed inclined system and the other for a single-axis tracking PV array system. Figure 8 depicts the results of the above analysis showing the averaged load profile vs that of a 500kWp solar PV system – one analysis for a fixed inclined system and the other for a single-axis tracking system.

Fig. 8 Energy consumption vs fixed and tracking PV generation systems

It was further calculated that the tracking system could generate approximately 1151MWh/annum compared with that of the fixed inclined system generating approximately 934MWh/annum. The estimated cost for a 500kWp fixed inclination PV system is ZAR9million with the cost for a single-axis tracking PV system estimated to be ZAR9.9million. The tracking system generates 23% more energy than the fixed inclination system per annum. However it should be noted that the tracking system costs approximately 10% more compared to the fixed inclination system.

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Table 2 shows a summary of the cost estimation for a 500kWp PV system for a fixed inclined system and that for a single-axis tracking system and the estimated annual energy generated each system. Inputs into this analysis included referencing Alfheldt, (2013)

Table 2: Summary of estimated annual energy generation, investment costs for a 500kWp fixed inclined and single-axis PV array system

DISCUSSION The South African Renewable Energy Independent Power Producer Programme (REIPP) is successfully implementing utility scale PV projects with the price for electricity being offered under Bid Window 4 being ZAR0.82/kWhr. This price is less than that of new build coal fired power stations. The CSIR has installed a 560 kWp, ground-mounted, single-axis PV tracking system, on its main campus in Pretoria where the Levelised Cost of Electricity of the CSIR system is ZAR0.83/ kWhr and is very competitive to the price offered under Bid Window 4. The CSIR’s solar PV system can be used as a base-line against which to compare similarly sized PV systems. Figure 9 depicts a stylised single-axis tracking PV array system

Figure 9: Schematic of single-axis tracking PV array system


7 This attractive cost of ZAR0.83/kWh implies that small scale PV systems can be implemented with the associated investment benefits. Based on a case study for a public entity the Time-of-Use tariff for this entity was investigated to establish the potential benefits of implementing a single-axis tracking solar PV system to generate electricity. Associated with the Time-of-Use tariff is the on-peak tariff period from 7:00am until 10:00am. Superimposing the solar PV generation curve onto the Time-of-Use tariffs for both summer and winter months provides for options to be considered with regards to demand-side management using solar PV based systems. During the summer months the solar energy has the potential to be utilised from approximately 6:00am in the morning until approximately 6:00pm in the late afternoon. During the winter months the solar energy has the potential to be utilised from approximately 7:00am in the morning until 5:00pm in the afternoon. For the 500kWp it was calculated that the single-axis tracking PV system could

SOLAR PV ARRAY SYSTEM

generate approximately 1151MWh/annum compared with that of the fixed inclined system generating approximately 934MWh/ annum. The estimated cost for a 500kWp fixed inclination PV system is ZAR9million with the cost for a single-axis tracking PV system estimated to be ZAR9.9million. Consequently the tracking based system generates 23% more energy than the fixed inclination system per annum because the tracking system is able to capture the solar radiation more efficiently during much of the day-light hours However it should be noted that the tracking system costs only approximately 10% more compared to the fixed inclination system. Consequently a fixed-axis tracking solar PV system can be used to mitigate against the morning on-peak tariff period without implementing any other demand-side measures. Furthermore, small scale single-axis tracking PV systems can also reduce the monthly electricity bill payable to bulk suppliers of electricity.

References

• Alfheldt. C., (2013) The localization potential of photovoltaics (PV) and strategy to support large scale roll out in South • Africa, Prepared for SAPIA, WWF and the dti, March 2013 • Bischof-Niemz, T. and Roro, K.T., (2015)“A guideline for public entities on cost-efficient procurement of PV assets”, 31st • European PV Solar Energy Conference and Exhibition (EU PVSEC 2015), Hamburg, Germany • REIPPP, online, available at http://www.ipprenewables.co.za/ [accessed 10 May 2016]

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Green Walls

fashionable or functional Piet Vosloo


8

G

reen, or vegetated walls in our built environment have become a newfound (in Europe rather a case of reinvented) architectural expression, often fashionable but rarely functional or both. Various authors have written on the benefits of green infrastructure such as urban forests, street trees, parks, turf-grass, green roofs and green walls in the modern urban context (Cameron et al. 2014; Dunnett & Kingsbury 2010 and Köhler 2008). Benefits, including a reduction of the Urban Heat Island effect (UHI-effect), reduced energy consumption, improved human indoor thermal comfort, absorption of noxious gases, trapping airborne particulates and improving the aesthetic of our cities, have been well researched and documented. However, the impression is often gained that some vegetated walls are merely designed as an architecturally fashionable elevation treatment; plant species selection is not done to achieve the environmental advantages that are possible in terms of water and nutrients demand, uptake of pollutants, appropriate shading and thermal insulation that could be achieved, systems that require large amounts of energy to pump and circulate irrigation, and regular plant replacement required by inappropriate light conditions (specifically for indoor vegetated walls). The modern day green or vegetated roof concept was advanced in Europe in the 1970s; other complementing forms of city greenery, such as vegetated walls were proposed by urban ecologists to achieve the ideal of maximum possible vegetation in the urban setting, while some prominent architects such as Friedensreich Hundertwasser (1928 – 2000) supported the idea of vegetated facades and green roofs and incorporated these ideas into their designs. Our cities’ buildings present an opportunity for the greening of large vertical surfaces, which, if left as they are, contribute to the UHI-effect. Lundholm and Richardson (cited in Francis & Lorimer 2011: 1430) have proposed that greater consideration be given to “…artificial urban

GREEN WALLS

habitats such as walls … as ‘analogue’ habitats that can support species from comparable natural habitats…” (in this case referring to vertical rock cliffs), and that these habitats could be improved by using appropriate ecological engineering techniques such as green facades or living walls. The practice of training plants to cover a wall surface is many centuries old and mainly relied on the particular climbing plant’s ability to cling to the wall surface, e.g. Boston ivy (Parthenocissus tricuspidata) and Tickey creeper (Ficus pumila). Köhler (2008) finds that about 100 years ago buildings in Europe, mostly residential rental developments, had no final plaster finish on the façades and instead owners planted creepers on the walls, leading to the long-held belief that the greening of walls was merely a cost saving measure. Modern day technologies for the greening of walls however support a much wider palette of plants to be used and allow those plants to reach much greater heights (Dunnett & Kingsbury 2010: 9). Probably the best known exponent of green wall applications is Patrick Blanc; his projects span several decades since the late 1970s and include more than 40 green wall projects worldwide. His work stems from his background in botany and which led him to explore and experiment with floristic diversity and ways in which plants exploit vertical surfaces (Köhler 2008: 245). Different types of green walls The generic term ‘green wall’ has become a somewhat confusing description for almost all building walls covered by, hosting or supporting vegetation. It is however important to make the distinction between the many various wall greening techniques and with that an understanding of which plant types can be used with these vastly varied construction methods. Based on definitions developed by various authors (Francis & Lorimer 2011; Dunnett & THE GREEN BUILDING HANDBOOK

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Kingsbury 2010; Pérez et al. 2011; Ottelé et al. 2011), the following concepts are explained: Green façades This term mainly refers to a wall on which climbing plants, such as the ivy species (typically Hedera helix or Parthenocissus tricuspidata and P. quinquefolia) are encouraged to cover the wall surface, either directly on the wall surface (see Figures 1 and 2: Direct green facade) or alternatively on a wire or trellis framework (see Figures 1 and 3: Indirect green façade), although the roots of the plants are still contained in a substrate at the base of the wall or planted in natural ground. The objective of the indirect green façade method is to create a ‘green curtain’ with a cavity between it and the building’s wall surface for wall and plant maintenance purposes and to avoid plant root and waterproofing damage to the building. The indirect green façade method has proven more sustainable than planting directly onto the wall surface, although the biggest constraint with green facades remains the limitation to use only climbing plants. Direct green facade

Indirect green facade

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Figure 1. Direct and indirect green facades (taken from Ottelé et al. 2011) Figure 2. Direct green façades (taken from Google Images 2016)

Figure 3. Indirect green façades (taken from Google Images 2016)

In terms of irrigation and nutrient supply green facades are usually simpler to maintain since both can be supplied to the roots at ground level. Living walls This term refers to a wall that incorporates vegetation in its own or sub-structure and which does not require the plants to be rooted in a substrate at the base of the wall as with green façades. Living wall systems are not dependent on a restricted range of climbing plants as with green facades; this allows for a far greater range of species to be utilised. The living wall approach thus increases the potential for utilising vegetated walls for biodiversity and reconciliation ecology, the latter which is defined by Francis and Lorimer (2011: 1429) as an approach by which the “… anthropogenic environment may be modified to encourage non-human use and biodiversity preservation without compromising societal utilization…” and which “…potentially represents an appropriate paradigm for urban conservation…” In this regard they suggest that


8 the installation of living roofs and walls, which have been shown to support a range of taxa at local scales, present a good opportunity to introduce reconciliation ecology in urban areas (ibid. 2011: 1429). Two generic approaches have developed over time: a living wall with the plants in boxes, pots or other ‘hard’ containers (see Figures 4, 5 and 7), and a system where the plants are held in position between two geotextile layer or in geotextile pockets (see Figures 4 and 6) • Living wall system with planter boxes • Living wall system with felt/geotextile mat layers

GREEN WALLS

kept separate from the wall via a waterproof membrane or a cavity. Pérez et al. (2011) find that most living wall systems can support non-climbing plants that are secured pots or containers or in pockets provided in a vertically hanging geotextile mats or panels and which are supplied with irrigation water and nutrients in solution via a drip feed system (see Figure 5). Living walls systems however typically require more intensive and specialised maintenance due to the location of the planters or pockets and the need to deliver irrigation and plant nutrients to higher levels. Some living wall systems however do not meet other sustainability criteria, e.g. low water use, low nutrient demand and low energy use, e.g. to pump irrigation water to the wall planting.

Figure 4. Living wall systems (taken from Ottelé et.al. 2011)

Both approaches have seen much research and development over the recent past and there are currently numerous systems (some patented) available on the market, such as the Vicinity Modular Vertical Garden ™ system (see Figure 5), Cape Contours’systems™ (see Figures 6 and 7), Geowalls Cellular systems™, Greenwalls VPS™ and many more.

Figure 5. The Vicinity Modular Vertical Garden system™. (taken from Vicinity Modular Vertical Garden 2016)

Living wall systems are typically modular and consist of an encased growing medium (a planter) placed onto the wall surface but

Figure 6. The Cape Contours Geotextile Pocket Panel system (taken from Cape Contours 2016)

Figure 7. The Cape Contours Modular Plant Pod system (Taken from Cape Contours 2016)

Sheweka & Magdy (2011: 594) propose a classification system for vegetated walls where THE GREEN BUILDING HANDBOOK

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they are divided into three fundamental types according to the morphology of the plants, types of growing media and construction method, see Table 1. Table 1. Comparison of three vegetated walls methods (adapted from Sheweka & Magdy 2011)

Figure 7. The Cape Contours Modular Plant Pod system (Taken from Cape Contours 2016)

Sheweka & Magdy (2011: 594) propose a classification system for vegetated walls where they are divided into three fundamental types according to the morphology of the plants, types of growing media and construction method, see Table 1.

Table 1. Comparison of three vegetated walls methods (adapted from Sheweka & Magdy 2011)

Type

Plant morphology

Wall climbing

Climbing plants

Hanging down

Plants with long hanging down stems

Module

Short plants

Growing media

Construction type

Soil on the ground or Minimal supporting in planters at ground structure is needed level Planted boxes and Soil in planted box at supporting structure higher levels as well should be provided at appropriate upper levels Lightweight panels Supporting sub-structure containing pockets for hanging or placing or pots of growing modules should be built on media facades

Classification i.t.o. green facades or living walls Direct or Indirect green facades Living wall

Living wall

Benefits of green facades and living Benefits of green facades and living walls walls The benefits and inherent value of green facades and living walls have been researched and expounded since the late 1970s by numerous authors such as Dunnett & Kingsbury (2010), Aragonés & Olivieri (2010), Cameron et.al. (2014), Sheweka & Magdy (2011) and Ottelé et al. (2011). Some of these benefits include: • Ameliorating the effect of urban pollution such as trapping dust, recycling CO2 and sequestering carbon • Absorbing many gaseous pollutants s u c h a s fo r m a l d e hyd e, Vo l a t i l e Natural vertical plant habitats Organic Compounds (benzene and trichloroethylene or TCE), airborne biological pollutants, carbon monoxide and nitrogen oxides, pesticides and disinfectants (phenols), and radon. These pollutants contribute to ‘sick building syndrome’ (Seaman 2009). Research has proven the ability of many often-used indoor plants to absorb these gaseous pollutants; these include the indoor palms such as the Areca palm (Chrysalidocarpus lutescens), Lady palm (Rhapis excelsa), Bamboo palm (Chamaedora seifrizzi) and the Dwarf date palm (Phoenix roebelenii) as well as the Dracaena (Dracaena deremensis), the Rubber plant (Ficus robusta) and the well-known Philodendron spp. (Seaman 2009). The benefits and inherent value of green facades and living walls have been researched and expounded since the late 1970s by numerous authors such as Dunnett & Kingsbury (2010), Aragonés & Olivieri (2010), Cameron et.al. (2014), Sheweka & Magdy (2011) and Ottelé et al. (2011). Some of these benefits include: • Ameliorating the effect of urban pollution such as trapping dust, recycling CO2 and sequestering carbon • Absorbing many gaseous pollutants such as formaldehyde, Volatile Organic Compounds (benzene and trichloroethylene or TCE), airborne biological pollutants, carbon monoxide and nitrogen oxides, pesticides and disinfectants (phenols), and radon. These pollutants contribute to ‘sick building syndrome’ (Seaman 2009). Research has proven the ability of many often-used indoor plants to absorb these gaseous pollutants; these include the indoor palms such as the Areca palm (Chrysalidocarpus lutescens), Lady palm (Rhapis excelsa), Bamboo palm (Chamaedora seifrizzi) and the Dwarf date palm (Phoenix roebelenii) as well as the Dracaena (Dracaena deremensis), the Rubber plant (Ficus robusta) and the well-known Philodendron spp. (Seaman 2009). • Absorbing some of the heat trapped in city environments, i.e. ameliorating the Urban Heat Island effect. Sheweka & Magdy (2011) find that ambient temperature in urban areas can be as much as 6°C warmer than the air in rural areas. • Acting as a shading device on sun-exposed walls or to a lesser extent as a thermal insulating barrier to building façades. In their study on the effect of thermal and illuminance performance of a green wall. Ojembarrena et al. (2013) and Sheweka & Magdy (2011) found that a vegetal layer on the building façade ameliorates the inside temperature due to the vegetation’s shading effect and the cooling influence of evapotranspiration from leaves; these effects reduce the temperature of outside air being introduced into the structure, in the process the vegetal layer helps to moderate uncomfortable summer conditions to comfortable ones. Research by Cameron et al. (2014) has shown that in terms of wall cooling potential, certain species, e.g. Fuchsia spp. promote evapotranspiration whereas shade cooling was more important with species such as Jasminum and Lonicera spp. • Increasing the biodiversity in urban contexts. • Absorbing noise and providing some sound insulation. • Improving visual and aesthetic aspects of cities’ buildings.

The vegetated wall systems described up to now do not specifically require plants that occur naturally on vertical rock faces; these are termed cremnophytes, from the Greek kremnos (cliff) and phyta referring to plants. If, however, it is a requirement to mimic an outdoor cremnophyte habitat on a building wall, other considerations pertaining to a vertical habitat have to be taken in account. The verticality of walls affects the micro-climate of vegetated walls in urban areas in the following ways: • The amount of direct solar radiation received on the surface • Moisture (precipitation) received and retained • Wind (the walls affect the wind speed and pattern and causes turbulence)

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• Absorbing some of the heat trapped in city environments, i.e. ameliorating the Urban Heat Island effect. Sheweka & Magdy (2011) find that ambient temperature in urban areas can be as much as 6°C warmer than the air in rural areas. • Acting as a shading device on sunexposed walls or to a lesser extent as a thermal insulating barrier to building façades. In their study on the effect of thermal and illuminance performance of a green wall. Ojembarrena et al. (2013) and Sheweka & Magdy (2011) found that a vegetal layer on the building façade ameliorates the inside temperature due to the vegetation’s shading effect and the cooling influence of evapotranspiration from leaves; these effects reduce the temperature of outside air being introduced into the structure, in the process the vegetal layer helps to moderate uncomfortable summer conditions to comfortable ones. Research by Cameron et al. (2014) has shown that in terms of wall cooling potential, certain species, e.g. Fuchsia spp. promote evapotranspiration whereas shade cooling was more impor tant with species such as Jasminum and Lonicera spp. • Increasing the biodiversity in urban contexts. • Absorbing noise and providing some sound insulation. • Improving visual and aesthetic aspects of cities’ buildings. Natural vertical plant habitats The vegetated wall systems described up to now do not specifically require plants that occur naturally on vertical rock faces; these are termed cremnophytes, from the Greek kremnos (cliff ) and phyta referring to plants. If, however, it is a requirement to mimic an outdoor cremnophyte habitat on a building wall, other considerations


8 pertaining to a vertical habitat have to be taken in account. The verticality of walls affects the microclimate of vegetated walls in urban areas in the following ways: • The amount of direct solar radiation received on the surface • Moisture (precipitation) received and retained • Wind (the walls affect the wind speed and pattern and causes turbulence) • Temperature differences; depending on aspect, wall material, thermal capacity of the wall, the temperature of the wall can vary drastically from surrounding level ground surfaces. In order to mimic a cremnophyte habitat, and as an alternative to the living wall approaches described above, a vertical surface can be created by stacking rock filled steel mesh baskets (gabions) with soil filled planters behind at various heights against the building’s wall to allow climbers and non-climbers to cover the gabions over greater heights; usually a void or working space is provided between the gabion screen and the building wall. This approach has some disadvantages, such as increased cost for the secondary or sub-structure to hold and support the gabions and for an accessible work space behind. An example of this approach is the cremnophyte wall at the Plant Sciences Building on the University of Pretoria’s main campus (designed by kwpCREATE Architects and Landscape Architects, see Figures 8 and 9 ( Vosloo 2016)

GREEN WALLS

Figure 8. The north-western living wall of the UP Plant Sciences building (Image by author)

Figure 9. Detail section through the rock face wall (Courtesy of kwpCREATE Architects & Landscape Architects)

The idea behind the wall (designed by kwpCREATE Architects and Landscape Architects) was to create a habitat for indigenous cremnophytes since these plants are very rare and rarely presented to the public in botanical gardens. The sourcing of indigenous cremnophytic plants proved difficult since these are, as a rule, not available commercially and the project relied heavily on specimens sourced from botanical gardens and speciality growers. The construction of the living wall consists of a rock filled gabion screen, supported on a steel frame, four storeys high and with soil filled planters in 11 rows over the total height behind the rock wall. Access for maintenance of the planters is via an 800mm wide workspace between the rock wall and the building’s external wall, see Figures 8 and 9. The plants are planted in the planter boxes and led through the rock screen to the outside via uPVC pipes cut open to allow for stem growth. Cremnophytic aloes such as Aloe hardyii are planted in soil-filled inclined uPVC pipes grounded in the planters behind, see Figure 9 (ibid. 2016). THE GREEN BUILDING HANDBOOK

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The introduction of obligate cremnophytic succulents on the UP living wall was a prime consideration, however, and in an attempt to also provide for opportunistic cliff dwellers, other species, not strictly succulents, have been introduced, thus requiring an artificial irrigation supply system. This has been achieved by the provision of a PVC dripper line to each row of planter boxes and which can be regulated either automatically or manually, depending on the amount of rainfall received (ibid. 2016). Conclusions There are distinct differences in application and function between green façades and living walls; whereas both approaches are generally referred to as green walls, designers should appreciate these differences when selecting an approach to best suit their application. When contemplating a vegetated wall on or in a building, and whether classified as a green façade or a living wall, consideration should be given to the following aspects: • The position of the growing medium relative to the plant roots and foliage • The morphology of the intended plant species to be used; i.e. short stemmed plants, creepers or climbers. • The water demand of the intended plant species to be used. • The ability of the intended plant species to be self-supported, climbing or clinging. • Whether the intended plant species are deciduous or evergreen since this will determine the amount of solar radiation penetrating through the foliage over all the seasons. • The ability of the intended indoor plant species to absorb noxious gases and trap airborne pollutants. Pérez et al. (2011) suggest that when considering vegetated walls as passive

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energy saving measures, four mechanisms should be kept in mind: • Shading of solar radiation by the vegetation. This will obviously be determined by the plant species and density of foliage. • Thermal insulation provided by the vegetation as a second building skin. The air cavity between the plant screen, covered with leaves in the summer, and the building façade acts as an insulation layer, whereas in the winter months and with deciduous plants, solar radiation is allowed in to heat up thermally massive walls. • The cooling effect around a building façade caused by evapotranspiration from the vegetated wall’s foliage and evaporation of moisture in the plant containers. • Screening or blocking of winds by the vegetated screen. The effect is mostly applicable in colder climates and is determined by the foliage density and the façades’ orientation in terms of the prevailing wind direction. The use of vegetated walls in South Africa is still in its infancy when compared to the practice in Europe. When designers are contemplating the use of vegetated walls, whether green façades or living walls, and understand the advantages of the various construction techniques, their sustainability in terms of function, maintainability, water and nutrient demands as well as selecting the most appropriate plant species, and bearing in mind South Africa’s mostly temperate climate, it is suggested that we will thereafter see many more examples in our cities. Only when the full environmental potential of green façades or living walls are understood and implemented, can the question be answered if ‘green walls’ are merely fashionable or functional or hopefully both.


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GREEN WALLS

References

• Aragonés, R.G. & Olivieri, F. 2010. Eco architecture: innovative façade design with vegetal elements: opaque and translucent green walls. Design Principles and Practices: An International Journal, Vol. 4 No. 2: 103-122. • Cameron, R.W.F., Taylor, J.E. & Emmett, M.R. 2014. What’s ‘cool’ in the world of green façades? How plant choice influences the cooling properties of green walls. Building and Environment Vol. 73: 198-207. • Cape Contours Living Green Walls. 2016. http://www.capecontours.co.za/living-green-walls (Accessed 17 May 2016) • Dunnett, N. & Kingsbury, N. 2010. Planting green roofs and living walls. London: Timber Press. 328 pp. • Francis, R.A. & Lorimer, J. 2011. Urban reconciliation ecology: The potential of living roofs and walls. Journal of Environmental Management Vol. 92: 1429-1437. • Google Images. 2016. Climbing wall plants (Accessed 25 May 2016) • Köhler, M. 2008. Green facades—a view back and some visions. Urban Ecosystems Vol. 11: 423–436. • Ojembarrena, J.A., Chanampa, M., Rivas, P.V., Olivieri, F., Aragonés, R.G., González, F.J.N. & Frutos, C.B. 2013. Thermal and illuminance performance of a translucent green wall. Journal of Architectural Engineering, Vol. 19 No. 4: 256–264. • Ottelé, M., Perini, K., Fraaij, A.L.A., Haas, E.M. & Raiteri, R. 2011. Comparative life cycle analysis for green façades and living wall systems. Energy and Buildings Vol. 43: 3419-3429. • Pérez, G., Rincón, L., Vila, A., González, J.M., & Cabeza, L.F. 2011. Green vertical systems for buildings as passive systems for energy savings. Applied Energy Vol. 88: 4854–4859. • Seaman, G. 2009. Top ten plants for removing indoor toxins. http://learn.eartheasy.com/2009/05/thetop-10-plants-for-removing-indoor-toxins/#sthash.fcEiGw9t.dpuf (Accessed 23 May 2016) • Sheweka, S. & Magdy, N. 2011. The living walls as an approach for a healthy urban environment. Energy Procedia Vol. 6: 596–597. • Vicinity Modular Vertical Garden. 2016. http://www.modularverticalgarden.com/#modularverticalgarden (Accessed 17 May 2016) • Vosloo, P.T. 2016. Green façades and living walls – a case study of the UP Plant Sciences’ vegetated wall. ArchSA Issue 80 July-August 2016.

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Phase Changing Materials (PCMs)

applications in buildings for human thermal comfort Tichaona Kumirai


9

D

ue to South Africa’s energy crisis and global climate change challenges, there is currently a major drive towards the use of renewable energy sources, and energy efficient and conservation interventions to ensure energy security for the country. Of all the energy users, the built environment has been identified as one of the largest untapped potential in energy efficiency opportunities and in reducing green-house gas emissions (Eskom, 2014). It has been estimated that as much as 30-40% of the world’s primary energy is consumed by the building sector. The biggest use in this sector is in heating and cooling applications, which contributes to at least a third of greenhouse gas emissions (Waqas and Din, 2013). In South Africa, the largest single end-use contribution to energy consumption especially in commercial buildings (includes office buildings, shopping centers, restaurants, and others) is from Heating, Ventilation and Air conditioning (HVAC) accounting as much as 26% of the total energy use (this excludes lighting, geysers, motors, pumps, and other specialised uses) (Milford, n.d.). South Africa is still dependent on conventional HVAC systems such as split unit air-conditioning systems, resistance heaters and centralised chiller plants which have high energy demands contributing an estimated 5400 MW (megawatts) nationally to electricity demand in peak periods (Eskom, 2010). This figure is expected to increase due to climate change (Osterman, et al., 2012). The South African climate change model predicted that by mid-century the South African coast will warm by around 1 to 2°C and the interior by around 2 to 3°C. By 2100, warming is projected to reach around 3 to 4°C along the coast, and 6 to 7°C in the interior (South Africa department of environmental affairs). There is an urgent need to improve the energy efficiency in buildings and reduce the peak heating and cooling loads. In order to reduce the energy demand of buildings, the South African government has implemented building standards such as SANS 10400-XA and SANS 204 which attempts to save energy by means of the maximum

PHASE CHANGING MATERIALS

allowable energy consumption per square meter of floor area per building classification for each of the climatic zones of South Africa. This chapter describes Phase Change Materials (PCMs) based thermal energy storage and its applications in buildings to provide passive regulation of indoor air temperature for human thermal comfort. Phase change materials (PCMs) The main use of PCMs is storing or releasing thermal energy as latent heat. A typical example of latent heat is the heat energy released or absorbed during a phase change (phase transition) of matter. The three main types of PCMs as shown in Figure 1 are organic, inorganic and eutectic of organic and inorganic compounds (Waqas and Din, 2013).

Figure 1: Types of PCMs (Waqas and Din, 2013).

Organic – paraffin Organic paraffin consists of hydrogen (H) and carbon (C) atoms. The general chemical formula for paraffin is C_n H_(2n+2) (Sharma and Sagara, 2005). For the range of 5≤n≤15 paraffin is a liquid and in the other cases waxy solids (Sharma and Sagara, 2005). Paraffin wax is mainly used in commercial organic heat storage PCM. (Sharma, et al., 2009) states that the melting point and latent heat of fusion for paraffin increases with an increased number of carbon atoms. ofandparaffin PCMs are Figure 1:Examples Types of PCMs (Waqas Din, 2013). Organicparaffin shown in Table 1. Organic paraffin consists of hydrogen (H) and carbon (C) atoms. The general chemical Table 1. Some examples of paraffin formula for paraffin is C H (Sharma and Sagara, 2005). For the range of PCMs 5 ≤ n ≤ 15 paraffin is a liquid and in the other cases waxy solids (Sharma and Sagara, 2005). Paraffin wax is mainly used inand commercial organic heat storage PCM. (Sharma, et al., (Sharma, Kitano Sagara, 2004) !

!"!!

2009) states that the melting point and latent heat of fusion for paraffin increases with an increased number of carbon atoms. Examples of paraffin PCMs are shown in Table 1. Name

Table 1. Some examples of paraffin PCMs (Sharma, Kitano and Sagara, 2004)

n-Tetradecane n-Pentadecane n-Hexadecane n-Heptadecane n-Octadecane

No. of “C” atoms 14 15 16 17 18

Melting point (°C) 4.5-5.6 10 18.2 22 28.2

Latent heat (kJ/kg) 231 207 238 215 245

The advantages and disadvantages of paraffin are listed in the Table 2 as per (Sharma, Kitano and Sagara, 2004): Advantages

Table 2. Advantages and disadvantages of paraffin PCMs

Disadvantages

THE GREEN BUILDING HANDBOOK presents a problem when high heat transfer 145

Paraffin waxes show no tendency to segregate. They are chemically stable They have high heats of fusion They have no tendency of super cooling.

Paraffin has low thermal conductivity. This

rates are required during the freezing cycle. Paraffin has a high volume change between the solid and liquid stages. This causes many


Organic- paraffin

Figure 1: Types of PCMs (Waqas and Din, 2013).

PHASE CHANGING 9 Organic paraffin consists ofMATERIALS hydrogen (H) and carbon (C) atoms. The general chemical

formula for paraffin is C! H!"!! (Sharma and Sagara, 2005). For the range of 5 ≤ n ≤ 15 paraffin is a liquid and in the other cases waxy solids (Sharma and Sagara, 2005). Paraffin wax is mainly used in commercial organic heat storage PCM. (Sharma, et al., 2009) states that the melting point and latent heat of fusion for paraffin increases with an increased number of carbon atoms. Examples of paraffin PCMs are shown in Table 1.

The advantages and disadvantages of paraffin Table 1. Some examples of paraffin PCMs (Sharma, Kitano and Sagara, 2004) are listed in the Table 2 as per (Sharma, Kitano Name No. of “C” Melting point Latent heat atoms (°C) (kJ/kg) and Sagara, 2004): n-Tetradecane n-Pentadecane n-Hexadecane n-Heptadecane n-Octadecane

14 15 16 17 18

4.5-5.6 10 18.2 22 28.2

231 207 238 215 245

Table 2. Advantages and disadvantages of paraffin PCMs

The advantages and disadvantages of paraffin are listed in the Table 2 as per (Sharma, Kitano and Sagara, 2004): Advantages

T a b l e 2 . Advantages and disadvantages of paraffin PCMs

Paraffin waxes show no tendency to segregate. They are chemically stable They have high heats of fusion They have no tendency of super cooling. Therefore nucleating agents are not necessary. Paraffin waxes are safe and non-reactive. They are compatible with all metal containers.

Disadvantages

Paraffin has low thermal conductivity. This presents a problem when high heat transfer rates are required during the freezing cycle. Paraffin has a high volume change between the solid and liquid stages. This causes many problems in container design. Paraffin’s are flammable. Paraffin can contract enough to pull away from the walls of the storage container greatly decreasing heat storage capacity. Commercial paraffin generally do not have sharp well-defined melting points. This decreases the efficiency of the heat storage system, as is no longer isothermal.

Organic – non-paraffin The non-paraffin organic PCMs consists of esters, fatty acids, alcohols and glycols (Sharma, Kitano and Sagara, 2004). Examples of organic non paraffin PCMs are shown in Table 3 and their advantages and disadvantages are shown in Table 4. The most widely used non-paraffin organics, as heat storage materials, are fatty acids like lauric, myristic, palmitic and stearic acid. The general formula describing all the Organicnon-paraffin fatty acid CH_3 (CH_2 )_2n∙COOH. The non-paraffin organic PCMs consists of esters, fatty acids, alcohols and glycols (Sharma, Kitano and Sagara, 2004). Examples of organic non paraffin PCMs are shown in Table 3 and their advantages and disadvantages are shown in Table 4. The most widely used non-paraffin organics, as heat storage materials, are fatty acids like lauric, myristic, palmitic and stearic acid. The general formula describing all the fatty acid Organicnon-paraffin CH! CH! !" ∙ COOH.

Table 3. Examples of organic non-paraffin’s PCMs (Sharma, Kitano and Sagara, 2004) The non-paraffin organic PCMs consists of esters, fatty acids, alcohols and glycols (Sharma, and Sagara, 2004). ExamplesPCMs of organic non paraffin PCMs are shown TableKitano 3. Examples of organic non-paraffin’s (Sharma, Kitano and Sagara, 2004) in Table 3 and their advantages and disadvantages are shown in Table 4. The most Material Melting point (°C) Latent heat (kJ/kg) widely used non-paraffin organics, as heat storage materials, are fatty acids like lauric, Formic acid 7.8 247 myristic, palmitic and stearic acid. The general formula describing all the fatty acid Acetic acid 16.7 187 CHGlycerin ! CH! !" ∙ COOH. 17.9 198.7 Butyl stearate 19 140 Polyethylene glycol-600 of organic 20-25 Table 3. Examples non-paraffin’s PCMs (Sharma,146 Kitano and Sagara, 2004) D-Lattic acid 26 184

Material

Melting point (°C)

Latent heat (kJ/kg)

Formic acid 7.8 247 Acetic acid Table 4. Advantages16.7 187 and disadvantages of organic non-paraffin PCMs Glycerin 17.9 198.7 Advantages Disadvantages Butyl stearate 19 140 Organic non-paraffin’s of fusion. These materials are Polyethylene glycol-600have high heat 20-25 146flammable and should not This decreases the size of the thermal storage be exposed to excessively high temperature, D-Lattic acid 26 184 flames or oxidizing agents (Sharma, Kitano and unit. Sagara, 2004). Organic non-paraffin’s have a sharp melting point. This maximises the efficiency of the heat Low thermal conductivity. storage system (Sharma, Kitano andand Sagara, Table 4. Advantages disadvantages of organic Instability at highnon-paraffin temperatures.PCMs 2004). 3-4 times more expensive than paraffin Advantages Disadvantages (Sharma, Kitano and Sagara, 2004). These materials are flammable and should not Organic non-paraffin’s have high heat of fusion. This decreases the size of the thermal storage be exposed to excessively high temperature, flames or oxidizing agents (Sharma, Kitano and unit.hydrates Salt Sagara, 2004). Organic non-paraffin’s have a sharp melting Salt hydrates are alloys of inorganic water (Sharma, et al., 2009). The salt and point. This maximises the efficiency of thesalts heat andLow thermal conductivity. thestorage watersystem combines to Kitano form and a crystalline matrix when thetemperatures. material is in a solid state (Sharma, Sagara, Instability at high 2004). Kitano and Sagara, 2004). The general (Sharma, formula salt hydrates is AB ∙ nH! O 3-4 times more for expensive than paraffin (Sharma, et al., 2009). The solid–liquid transformations of salt hydrates are regarded to (Sharma, Kitano and Sagara, 2004).

Table 4. Advantages and disadvantages of organic non-paraffin PCMs

be dehydration during melting and hydration during solidification of the salt hydrate. At

Salt hydrates shown in Equation 2, or into a lower hydrate and water Equation 1. Salt hydrates AB ∙ nH O → AB ∙ mH O + n − m H O (1) Salt hydrates are alloys of inorganic salts and water (Sharma, et al., 2009). The salt and AB ∙ nHhydrates O → AB + nH O are alloys of inorganic salts and (2) Salt the water combines to form a crystalline matrix when the material is in a solid state Sharma, Kitano and Sagara (2004) states the three types of behaviour of Salt hydrates (Sharma, Kitano and Sagara, 2004). The general formula for salt hydrates is AB ∙ nH O undergoing a phase transformation as congruent, incongruent and semi congruent. (Sharma, et(Sharma, al., 2009). The solid–liquid of salt hydrates are regarded to water al.,transformations The and Congruent melting is where allet the water in2009). the crystalline matrixsalt is separated fromthe the be dehydration during melting and hydration during solidification of the salt hydrate. At salt as shown in equation 2. Incongruent melting is where some of the water remains in the point the as saltshown hydrate crystals breakup anhydrous salt are andmatrix water as water combines toEquation form a into crystalline the melting salt after melting in 1. Examples of salt hydrates shown in shown in Equation 2, or into a lower hydrate and water Equation 1. Table 5. AB ∙ nH O → AB ∙ mH O + n − m H is O in a solid state (Sharma, (1) when the material AB ∙ nH O → AB + nH O (2) Sharma, Kitano and Sagara (2004) states the three types of behaviour of Salt hydrates Kitano and Sagara, 2004). The general formula undergoing a phase transformation as congruent, incongruent and semi congruent. the melting point the salt hydrate crystals breakup into anhydrous salt and water as ! !

! !

!

!

!

!

!

!

!

Congruent melting is where all the water in the crystalline matrix is separated from the salt as shown in equation 2. Incongruent melting is where some of the water remains in the salt after melting as shown in Equation 1. Examples of salt hydrates are shown in Table 5.

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THE GREEN BUILDING HANDBOOK

for salt hydrates is AB∙nH_2 O (Sharma, et al., 2009). The solid–liquid transformations of salt hydrates are regarded to be dehydration during melting and hydration during solidification of the salt hydrate. At the melting point the salt hydrate crystals breakup into anhydrous salt and water as shown in Equation 2, or into a lower hydrate and water Equation 1. AB∙nH2O­­­–>AB∙mH2 O+(n-m) H2O (1) AB∙nH2O–>AB+nH2O (2) Sharma, Kitano and Sagara (2004) states the three types of behaviour of Salt hydrates undergoing a phase transformation as congruent, incongruent and semi congruent. Congruent melting is where all the water in the crystalline matrix is separated from the salt as shown in equation 2. Incongruent melting is where some of the water remains in the salt after melting as shown in Equation 1. Examples of salt hydrates are shown in Table 5.   Table 5. Examples of salt hydrates PCMs Material

K ! HO! ∙ 6H! O KF ∙ 4H! O K ! HO! ∙ 4H! O

Table 5. Examples of salt hydrates PCMs

LiBO! ∙ 8H! O FeBr! ∙ 6H! O CaCl! ∙ 6H! O

NaMaterial ! SO! ∙ 10H! O (Glaubeur’s K ! HO! ∙ 6H! O salt) KF ∙ 4H! O K ! HO! ∙ 4H! O

Melting point (°C)

Latent heat (kJ/kg)

25.7

289

14 18 18.5

27 29-30

108 330 231

105 170-192

Table 5. Examples of salt hydrates PCMs

Melting point (°C) 32 14 18 18.5

Latent heat (kJ/kg) 251-254 108 330 231

PCMs LiBO! ∙ 8H! O Table 6. Advantages 25.7and disadvantages of Salt hydrates 289

Table 6. Advantages andDisadvantages disadvantages of Salt Advantages hydrates PCMs FeBr! ∙ 6H! O 27 105 CaCl! ∙ 6H! O 29-30 170-192 Low cost and easy availability. Many salt Salt hydrates have problem of segregation Na! SO! ∙ 10H! O (Glaubeur’s 32 251-254 hydrates are sufficiently inexpensive for use in (Sharma, Kitano and Sagara, 2004). Segregation salt) thermal storage (Sharma, Kitano and Sagara, of salt hydrates reduces the amount of salt hydrate that is actively available for heat 2004). storage. Abhat, 1983, reports a decrease in Salt hydrates have a sharp melting point. This latent heatofofSalt Na! SO O after 1000 cycles Table 6. Advantages and disadvantages hydrates maximises the efficiency of the heat storage ! ∙ 10H!PCMs (melt and freeze). system (Sharma, Kitano and Sagara, 2004). Advantages Disadvantages Salt hydrates shows signs of super cooling Salt hydrates have a high thermal conductivity (Sharma, Kitano andproblem Sagara,of 2004). when withavailability. other heatMany storage Lowcompared cost and easy saltPCMs Salt hydrates have segregation hydratesKitano are sufficiently inexpensive forcan use in (Sharma, Kitano andcorrosion Sagara, 2004). Segregation (Sharma, and Sagara, 2004). This Salt hydrates causes in metal thermalheat storage (Sharma, of salt hydrates reduces the amount ofthermal salt increase transfer in andKitano out ofand theSagara, storage containers that are commonly used in hydratesystems that is actively available 2004). storage (Sharma, Kitano for andheat Sagara, unit. storage. Abhat, 1983, reports a decrease in 2004). Salthave hydrates point. This They high have heat aofsharp fusionmelting (Sharma, Kitano latent heat of Na! SO! ∙ 10H! O after 1000 cycles maximises the efficiency of the heat and Sagara, 2004). This decreases thestorage size of the (melt and freeze). systemstorage (Sharma, Kitano and Sagara, 2004). thermal unit. Salt hydrates shows signs of super cooling Salt hydrates have a high thermal conductivity (Sharma, Kitano and Sagara, 2004). when compared with other heat storage PCMs (Sharma, Kitano and Sagara, 2004). This can Salt hydrates causes corrosion in metal Selection criteria candidate PCM containers that are commonly used in thermal increase heat transferfor in and out of the storage storage (Sharma, Kitano and Sagara, for unit. The desirable thermodynamic, kinetic, chemical systems and economic properties 2004). They have high heat of fusion (Sharma, Kitano candidate PCM for free cooling application are as follows: and Sagara, 2004). This decreases the size of the thermal storage unit.

PCM melting point

a

Butala and Stritih, 2009 states that if a wrong PCM is selected for a particular Selection criteria PCM solidify nor melt, and this leads to an application, the PCM for willcandidate neither totally

insufficient cooling potential storage. For chemical free cooling PCMs should Selection criteria for candidate The desirable thermodynamic, kinetic, andapplications economic PCM properties for be a selected in such way the cooled air temperature during melting process is within candidate PCM afor freethat cooling application are as follows: the range of defined human thermal comfort levels (Waqas and Din, 2013; Mosaffa, et The desirable thermodynamic, kinetic, chemical al.,PCM 2013). Researchers melting point have provided different criteria to choose the melting point of a PCM that will be applicable in a given application: Butala and Stritih, 2009 properties states that if a wrong selected for a particular and economic forPCM a iscandidate PCM application, the Butala PCM will neither totally solidify nor melt, and this to an • Stritih and (2007) state that in order to achieve sufficient heatleads transfer, cooling potential storage. For free cooling applications PCMs should be the temperature difference between the ambient summer air temperature and forinsufficient free application are as follows: selected in cooling such a way that the cooled air temperature during melting process is within the PCM melting temperature should be within the range of 3-5ºC. the range of defined human thermal comfort levels (Waqas and Din, 2013; Mosaffa, et • Waqas and Din (2013) states that the melting point of PCM must be close to the al., 2013). Researchers have provided different criteria to choose the melting point of a designed room temperature. PCM that will be applicable in a given application:

PCM• Stritih melting point and Butala (2007) state that in order to achieve sufficient heat transfer, temperature difference between the ambient summer air temperature and Butalathe and Stritih, 2009 states that if a wrong the PCM melting temperature should be within the range of 3-5ºC. and Din (2013) states that the melting point of PCM must be close to the PCM• isWaqas selected for a particular application, the designed room temperature.


9

PHASE CHANGING MATERIALS

PCM will neither totally solidify nor melt, and lesser amount of material is required to store this leads to an insufficient cooling potential a given amount of energy Abhat, 1983. storage. For free cooling applications PCMs should be selected in such a way that the Density cooled air temperature during melting process A higher density results in a smaller container is within the range of defined human thermal to hold the material Abhat, 1983. comfort levels (Waqas and Din, 2013; Mosaffa, et al., 2013). Researchers have provided Specific heat different criteria to choose the melting point High solid and liquid specific heats provide of a PCM that will be applicable in a given additional sensible heat capacities for the heat storage system Abhat, 1983. application: • Stritih and Butala (2007) state that in order to achieve sufficient heat transfer, Thermal conductivity the temperature difference between the High solid and liquid thermal conductivities ambient summer air temperature and are desirable so that the temperature gradients the PCM melting temperature should be required for charging and discharging the within the range of 3-5ºC. PCM are small (Abhat, 1983). Higher thermal • Waqas and Din (2013) states that the conductivity ensures high heat transfer melting point of PCM must be close to coefficients during storing and utilisation of thermal energy. The higher the heat transfer the designed room temperature. • Arkar and Medved (2007) proposed a rates, the smaller is the required heat transfer formula for determining the optimum area. PCM melting temperature as: Tp=Ta+2 Kelvins Congruent melting (3) The PCM should melt completely so that Where the liquid and solid phases are identical in Tp O p t i m a l PCM m e l t i n g composition. Otherwise the difference in temperature in Kelvins (K) densities between the solid and liquid causes segregation results in changes in the chemical Ta Calculated average ambient air temperature in the summer months composition of the PCM (Abhat, 1983). This (K) leads to a reduction in the heat storage capacity • Waqas and Kumar (2011) suggest that of the PCM. PCM based thermal storage performance is maximised when the PCM melting Super cooling temperature is equal to the comfort The PCM should exhibit little or no super temperature of the hottest summer cooling during solidification. The molten PCM month. must solidify at its thermodynamic solidification Geetha and VeraJ (2012) states that the temperature. This is achieved through a high melting temperature of the phase change rate of nucleation and growth rate of the material has to be at the middle of the crystals. The super cooling may be suppressed diurnal extreme temperatures, then an equal by introducing an effective nucleating agent temperature difference is available for both (Abhat, 1983). melting and solidification. Chemical stability Heat of fusion The PCM should show chemical stability with A high heat of fusion per unit mass is a merit no chemical decomposition so that a high point for the selection of a PCM so that a latent thermal energy storage capacity is THE GREEN BUILDING HANDBOOK

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PHASE CHANGING MATERIALS

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THE GREEN BUILDING HANDBOOK

9


9 ensured throughout the life of the system. The PCM shouldnâ&#x20AC;&#x2122;t corrode construction materials (Abhat, 1983). Safety The PCM should be non-poisonous, nonflammable and non-explosive. Economic The PCM should be available in large quantities and be inexpensive. Abhat (1983) states that there exist no single PCM that can fully satisfy all the desirable properties listed above. However PCM melting temperature is the most important factor and must always be selected carefully (Mehling and Cabeza, 2008; Arkar, Vidrih and Medved, 2007). Phase change materials in building applications The two main ways for using phase change materials to passively regulate indoor thermal environment are free cooling and integrating PCMs into the building envelope to increase thermal mass. Free cooling: The free cooling technique utilizes a separate thermal storage unit (PCM-air heat exchanger) for the storage of the cooling potential at night and a mechanical device, for example a fan, is used to move air (heat transfer fluid) for storage and extraction of the cooling potential from the storage unit (Waqas and Din, 2013; Raj and Velraj, 2011). The device is used for passively pre-cooling summer ambient air (fresh air) before introduction into the building or cooling recirculated air thereby reducing the ventilation cooling load portion of the total building cooling load. The operation principle for a PCM based free cooling technique is illustrated in Figure 2. During day time dampers 1 and 4 are closed and dampers 2 and 3 are opened so the hot room air circulating through the PCM module gets cooled and the cold air is again circulated to the room. This causes the PCM to gradually

PHASE CHANGING MATERIALS

melt. During night time dampers 1 and 4 open and dampers 3 and 2 are closed and the cool ambient air flows through the storage unit and takes away the heat from the liquid PCM which will start to solidify at a certain temperature. In this way solidification of PCM occurs during the night.

Figure 2. Working operation of a free cooling system adapted from Kalaiselvama, et al., 2014.

Climatic applicability of PCM based free cooling The effectiveness of reducing the ventilation cooling load of PCM-based free cooling mainly depends on the diurnal temperature range (the difference between the daily maximum and minimum temperature for a particular place) (Waqas and Din, 2013). According to Waqas and Din, 2013, the application of PCM performs efficiently in climatic conditions with a diurnal temperature range between 12 and 15ÂşC. Zalba, et al., 2004 argues that for climates where the diurnal temperature range is less, PCM-based free cooling will require careful design consideration of the heat exchanger including selection of an appropriate PCM and encapsulation. PCM-air heat exchanger designs Different types of PCM-air heat exchangers have been designed, developed and studied for free cooling applications. Packed bed PCM-air heat exchanger A packed bed PCM-air heat exchanger consist of PCM material that is encapsulated in small spheres or other geometrical shapes and placed in a larger container. The heat transfer fluid (air) stream passes through the bed. Arkar and Medved (2007) investigated THE GREEN BUILDING HANDBOOK

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PHASE CHANGING MATERIALS

9

a packed bed PCM-air heat exchanger located in the ventilation duct. The free cooling system consisted of two packed bed PCM-air heat exchangers: one for cooling the fresh supply air and the other for cooling the re-circulated indoor air.

Figure 3. Packed bed PCM-air heat exchanger studied by Arkar and Medved (2007).

Nagano et al., (2006) studied a floor mounted packed bed PCM-air heat exchanger. The PCM was granulated as shown in Figure 4 b and packed. Outdoor air is supplied into the room through grills located on the floor as illustrated in Figure 4. The air is exhausted through high level outlet air terminals located in the ceiling. This form of ventilation is called displacement ventilation. The opinion is expressed that PCM-air heat exchanger for free cooling have a great potential to be applied in a displacement ventilation system when compared to a mixed ventilation system. This is because of the lower temperature differential requirement between supply air and room air in a displacement ventilation system.

The major drawback of packed bed PCMair heat exchanger is the high pressure drop across the heat exchanger (Charvat, et al., 2014). This causes an increase in the fan energy consumption. Shell and tube PCM-air heat exchanger For a shell and tube heat exchanger, the PCM can be placed either in the shell with the heat transfer fluid (air) circulating inside the tubes or PCM inside the tubes with the air flow in the shell. Raj and Velraj, (2011) developed a shell and tube heat exchanger which had the PCM on the shell side and air flow on the tube side. The heat exchanger is a modular design. See isometric view of a module in Figure 5. Air spacers of 150 mm were provided between the modules. According to Raj and Velraj, 2011, these air spacers increase the retention time of the air. This increases heat transfer between the air and the PCM. This is only effective for air velocities below 2 m/s Raj and Velraj (2011). Reports that the modular heat exchanger arrangement is suitable for free cooling application where the diurnal temperature variation is low (Raj and Velraj 2011).

Figure 5. Isometric view of one module for the shell and tube PCM-air developed by Raj and Velraj, 2011.

Figure 4. a) Floor mounted packed bed PCM-air heat exchanger, b) granulated PCM (Nagano, et al., 2006).

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THE GREEN BUILDING HANDBOOK

Plate PCM-air heat exchanger A plate PCM-air heat exchanger consists of a PCM material that is encapsulated inside a plate and placed in larger container.


9 The plates can be oriented vertically or horizontally parallel to each other with air gaps between the plates. Studies have shown that the best plate orientation is vertical (Charvat, et al., 2014). Charvat, et al., 2014 used horizontally orientated Rubitherm™ compact storage modules (CSM) (See Figure 6 and 7) in their experiment. They found that the PCM in the fully melted state will collect at the lower part of the container (CSM panel) and there will be an air gap between the PCM and the upper surface of the container. That gap can significantly influence heat transfer between the PCM and the air passing through the heat storage unit. In support of the view Farid et al., 2004 states that in a horizontal plate orientation, volume contraction during solidification reduces the heat transfer surface area and also separates the PCM from the heat transfer surface, thus increasing the heat transfer resistance dramatically.

Figure 6. Illustration of a heat storage unit containing 100 Rubitherm™ compact storage modules used in the investigation by Charvat, et al., (2014).

PHASE CHANGING MATERIALS

uniformly distributed bulges across the panel surface.

Figure 7. Rubitherm™ plate encapsulated PCM (Rubitherm, 2015).

Figure 8 shows a commercially available (FSLB-PCM) fan coil air conditioning system which contains plate encapsulated PCM (labelled PCM-stack in Figure 8). The FSL-B-PCM unit is designed to be wall-mounted (Trox Technik, 2015). The unit obtains fresh summer outdoor air through an opening in the façade. The summer outdoor air is first cooled by the plate encapsulated PCM modules before it is discharged into the room. In case of very high outdoor air temperatures, the unit operates by mixing of secondary air and outdoor air or only recirculates secondary air (Trox Technik, 2015). This operation mode ensures slower rate of melting of the PCM. This enables the PCM storage unit not to discharge so quickly. The product uses either paraffin or salt hydrates with melting points between 20°C to 25°C (Trox Technik, 2015). The manufacturer claims that a pleasant room temperature can be ensured for up to 10 hours (Trox Technik, 2015).

An example of a commercially available PCM encapsulated in a plate is the Rubitherm™ compact storage modules (CSM) shown on Figure 7. The plate is made of two identical cavities of aluminium plates filled with the PCM. The cavities are joined at two centred points and stuck together at their frames (Rubitherm, 2015). The dimensions for the Rubitherm Compact Storage Unit (CSM) panel are 450 x 300 mm. The CSM panel has THE GREEN BUILDING HANDBOOK

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9 Figure 8. Illustration of FSL-B-PCM a commercially available air-conditioning system with plate encapsulated PCM ( Trox Technik, 2015).

Figure 9 shows a prefabricated plate PCM-air heat exchanger that was used in a building air conditioning project in Germany (Lembke, 2014). The PCM-air HX consist of 18 modules of Rubitherm PCM plates. Each module contains 15 plates which are separated by an air gap of 5 mm.

Figure 9. Illustration of PCM plates stacked in an air duct Lembke, 2014.

Marin et al., 2005 considered shell and tube and plate PCM-air heat exchangers in the design of their thermal storage unit: they opted for a plate heat exchanger because of the following advantages: • The heat transfer rate in the PCM can be controlled with the choice of thickness of the encapsulation (Marin et al., 2005). • Both processes of phase change are symmetric in relation to the two sides of the plates (Marin et al., 2005). • Flat plates offer a larger heat transfer surface area per unit volume of the thermal energy storage system; this enables a smaller and effective system (Marin et al., 2005). • Less pressure drop of the air is experienced. This leads to a lower electrical power requirement of the fans. • The use of flat plate encapsulation allows an easier design of the thermal energy storage system (Marin et al., 2005).

PHASE CHANGING MATERIALS

Very effective heat transfer since a single plate is surrounded by two heat transfer fluid streams (Cengel, 2008). • Plate heat exchangers can be expanded with increased demand for heat transfer by simply mounting more plates (Cengel, 2008). •

Passive building systems. For passive applications, PCMs are integrated into the building envelope to increase the thermal mass. This is especially beneficial in lightweight constructions, which have a low thermal energy storage capacity. Kumirai and Conradie (2013) showed that lightweight buildings exhibit large temperature fluctuations in the summer due to excessive over heating caused by a lack of thermal mass. PCMs added onto the building envelope reduce indoor temperature fluctuations and also reduce the building thermal loads attributed to the building envelope thereby lowering space conditioning energy consumption. For passive building system, only PCMs that have a melting temperature close to human thermal comfort temperature (20–28ºC) can be used (Ravikumar and Srinivasan, 2008). The main methods for incorporating PCM into building materials include the use of gypsum plaster boards and other structural boards, blending PCM with thermal insulations, and by macro-packaging. PCM enhanced wall boards Gypsum plasterboard has a heat capacity of 840J/kg.K, a density of 950 kg/m3 and a typical thickness of 12.5 mm (Baetens, et al., 2010). The calculated overall heat capacity of gypsum plasterboard is 10 kj/m2K as calculated using equation 4. Hoverall=heat capacity×density×thickness (4) Baetens, et al., (2010) states that enhancing gypsum plasterboards with PCMs results in an overall heat capacity of 550 kj/m2K to 800 kj/ m2K which is comparable to the overall heat capacity of concrete (552 kj/m2K). THE GREEN BUILDING HANDBOOK

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Methods of incorporating PCM into wall boards There are generally two methods for incorporating PCMs into wallboards (Baetens, et al., 2010): 1.

2. • • • •

Encapsulating PCM into pellets and using a binder to produce the wallboard: Baetens, et al., (2010) states that the disadvantage of this method is that pellets have low surface area to volume ratio thereby reducing the overall heat capacity. The second method is impregnating PCMs into wall boards. The procedure of impregnating is as follows: Melt PCM at controlled temperature Introduce aggregates into the molten PCM; the molten PCM coats the aggregates Mix coated aggregates with binder Press the mixture to obtain a board

Use of PCM panels in building envelope Castel, et al., (2010) applied Rubitherm CSM panels on the wall of a cubicle (See Figure 10). The results show that under freefloating conditions, the peak temperatures inside the closed cubicle reduced by 1°C and the temperature fluctuations were significantly reduced, relative to a cubicle without PCM (Castel, et al., 2010).

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Figure 10. Brick cubicle with RT-27 and polyurethane (Castel, et al., 2010).

Jin et al, 2014 conducted PCM wall experiments to analyse the effects of PCM location on the thermal performance of the wall. The PCM locations ranged from close to the indoor environment to close to outdoor environment as shown in Figure 11 (1 –gypsum wall board, 2-insulating layer, 3-OSB, 4-PCM layer). The experimental results showed that location 1/5L (see c in Figure 11) was the optimal PCM location in the wall.

Figure 11. Schematic of wall construction (a) control wall (No PCMTS) (b) location 0/5L (c) location 1/5L (d) location 2/5L (e) location 3/5L (f ) location 4/5L (g) location 5/5L.

Conclusions PCMs application in buildings is seen as a promising technology that can reduce building air-conditioning energy demand significantly. Most of the studies on PCM building applications are small scale experiments and theoretical models. There is a lack of demonstration projects. It is of high importance to setup pilot projects to show the feasibility. Waqas and Din, 2013 identified only seven companies in the whole world which manufacture PCMs for building applications. There is a gap in Southern Africa to locally develop PCMs that suit the unique climatic and temperature


9 profiles for Southern Africa. The thermal performance need to be tested in full building applications. Incorporating PCMs in the building envelope for light weight structures can offset the disadvantages on thermal

PHASE CHANGING MATERIALS

performance that are normally associated with these structures.

References

• [1]. Abhat. 1983. Low temperature latent heat thermal energy storage: Heat storage materials. Solar Energy Vol. 30(4). Pp. 313-332. • [2]. Arkar, C. and Medved, S., 2007. Free cooling of a building using PCM heat storage integrated into the ventilation system. Solar Energy, 81, pp.1078-1087. • [3]. Arkar, C., Vidrih, B. and Medved, S., 2007. Efficiency of free cooling using latent heat storage integrated into the ventilation system of a low energy building. International Journal of Refrigeration, 30(2007), pp.134-143. • [4]. Baetens, R., Jelle, B.P. and Gustavsen, A., 2010 . Phase change materials for building applications: A state-of-the-art review. Energy and Buildings , 42. pp. 1361–1368. • [5]. Butala, V. and Stritih, U., 2009. Experimental investigation of PCM cold storage. Energy and Buildings, 41(2009), pp.354-359. • [6]. Castell, A., Martorell, I., Medrano, M., Pe´ rez, G. and Cabeza, L.F., 2010. Experimental study of using PCM in brick constructive solutions for passive cooling. Energy and Buildings, 42 (2010), pp. 534–540. • [7]. Cengel, Y.A., 2008. Introduction to thermodynamics and heat transfer. 2nd ed. Reno, Nevada, USA: McGraw-Hill. • [8]. Charvat, P., Klimes, L., Ostry, M., 2014. Numerical and experimental investigation of a PCM-based thermal storage unit for solar air systems. Energy and Buildings, 68 (2014) pp.488–497. • [9]. Eskom Integrated Demand Management, 2014. Energy Efficiency opportunities in South Africa: Commercial Sector. Available at http://www.safma.co.za/portals/0/Commercial_ Sector_component.pdf, accessed 10 February 2016. • [10]. ESKOM, 2010. Demand side management-air-conditioning facts. Available at http:// www.eskom.co.za/content/dsm_0002airconfactsrev2~1.pdf.[Accessed 4 November 2011]. • [11]. Farid, M.M., Khudhair, A.M., Razack, S.A.K. and Al-Hallaj, S., 2004. A review on phase change energy storage: materials and applications. Energy Conversion and Management, 45 (2004), pp.1597-1615.

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• [12]. Geetha, N.B. and Velraj, R., 2012. Passive cooling methods for energy efficient buildings with and without thermal energy storage – A review. Energy Education Science and Technology Part A: Energy Science and Research, 29(2), pp.913-946. • [13]. Jin, X., Zhang, S., Xu, X. and Zhang , X., 2014. Effects of PCM state on its phase change performance and the thermal performance of building walls. Building and Environment , 81 (2014) pp.334-339. • [14]. Kalaiselvama, S., Suresh Kumara, K.R., Sriram, V., 2014. study of heat transfer and pressure drop characteristics of air heat exchanger using PCM for free cooling applications. Thermal Science, [online] Available at: http://www.doiserbia.nb.rs/img/doi/03549836/2014%20OnLine-First/0354-98361400096K.pdf • [15]. Kumirai, T and Conradie, D.C.U. 2013. Thermal performance of heavy-weight and lightweight steel frame construction approaches in the central Pretoria climate. Journal for New Generation Sciences, vol. 11(3), pp 1-20 • [16]. Lembke, T., 2014. Illustration of practical application of PCM plates in air duct. [Photograph] ( Tobias Lembke, Rubitherm technologies own private collection). • [17]. Marin, J.M., Zalba, B., Cabeza, L.F., Mehling, H., 2005. Improvement of a thermal energy storage using plates with paraffin–graphite composite. International Journal of Heat and Mass Transfer, 48(2005), pp.2561–2570. • [18]. Mehling, H. and Cabeza, L.F., 2008. Heat and cold storage with PCM an up to date introduction into basics and applications. Germany: Springer-Verlag Berlin Heidelberg • [19]. Milford, R. Perspective on energy Efficiency Building Regulations; A South African Perspective. Available at http://www.energy.gov.za/cop%2017/CopFiles/ PerspectiveOnEnergyEfficiencyBuilding.pdf, accessed 10 February 2016. • [20]. Mosaffa, A.H., Ferreira, C.A.I., Talati, F., Rosen, M.A., 2013. Thermal performance of a multiple PCM thermal storage unit for free cooling. Energy Conversion and Management 67(2013), pp.1–7. • [21]. Nagano, K., Takeda, S., Mochida, T., Shimakura, K and Nakamura,T., 2006. Study of a floor supply air conditioning system using granular phase change material to augment building mass thermal storage-Heat response in small scale experiments. Energy and Buildings , 38 (2006), pp.436–446. • [22]. Osterman, E., Tyagi, V.V., Butala, V., Rahim, N.A. and Stritih, U., 2012. Review of PCM based cooling technologies for buildings. Energy and Buildings, 49(2012), pp.37-49. • [23]. Raj, V.A.A. and Velraj, R., 2011. Heat transfer and pressure drop on a PCM-heat exchanger module for free cooling applications. International Journal of Thermal Sciences, 50(2011), pp.1573-1582. • [24]. Ravikumar, M. and Srinivasan,P.S.S., 2008. Natural cooling of building using phase change material. International Journal of Engineering and Technology, Vol. 5, No. 1, 2008, pp. 1-10 • [25]. Rubitherm Phase Change Material, 2015. Macroencapsulation – csm pcm in aluminum case.[online] Available at: http://www.rubitherm.eu/en/index.php/productcategory/makroverkaspelung-csm [Accessed 6 October 2015]. • [26]. Sharma, A., et al. 2009. Review on thermal energy storage with phase change materials and applications. Renewable and Sustainable Energy Reviews, 13, pp.318-345. • [27]. Sharma, S.D. and Sagara, K., 2005. Latent heat storage materials and systems: A review. International Journal of Green Energy, 2: 1–56, 2005

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• [28]. Sharma, S.D., Kitano, H. and Sagara, K., 2004. Phase Change Materials for Low Temperature Solar Thermal Applications. Res. Rep. Fac. Eng. Mie Univ., Vol. 29, (2004), pp. 31-64. • [29]. South Africa department of environmental affairs. National climate change response white paper. Available at: https://www.environment.gov.za/sites/default/files/legislations/ national_climatechange_response_whitepaper.pdf. • [30]. South African Bureau of Standards, 2011. SANS 10400-XA: 2011 edition 1 The application of the national building regulations: Energy usage in buildings. Pretoria South Africa: SABS Standards Division. • [31]. South African Bureau of Standards, 2011. SANS 204:2011 edition 1 Energy efficiency in buildings. Pretoria South Africa: SABS Standards Division. • [32]. Stritih, U. and Butala, V., 2007. Energy saving in building with PCM cold storage. International Journal of Energy Research, 31(2007), pp.1532-1544. • [33]. Trox Technik™, 2015. Air-water systems for air conditioning: Design manual. [online] Available at: http://www.troxuk.co.uk/downloads/3bd087e488d58b63/s_aws_air_water_systems_en.pdf [Accessed 13 March 2015]. • [34]. Waqas, A. and Din, Z.U., 2013. Phase change material (PCM) storage for free cooling of buildings: A review. Renewable and sustainable Energy Reviews, 18, pp.607-625. • [35]. Waqas, A. and Kumar, S., 2011. Utilization of latent heat storage unit for comfort ventilation of buildings in hot and dry climates. International Journal of Green Energy, 8, pp.1-24. • [36]. Zalba, B., Marin, J.M., Cabeza, L.F. and Mehling, H., 2004. Free-cooling of buildings with phase change materials. International Journal of Refrigeration, 27 (2004), pp.839–849.

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MSC1607-004

Frank Gehry’s architecture is unrivalled in its simple complexity. The Fondation Louis Vuitton in the Bois Du Boulogne, Paris is one of the most remarkable feats of architectural engineering. What made it possible was the use of structural duplex stainless steel to support the glass sails. As stainless steel is the only man-made noble metal, you’ll see that stainless doesn’t have to be bright to be brilliant.

MSC1607-004

Stainless Steel. It’s Simply Brilliant.

Frank Gehry’s architecture is unrivalled in its simple complexity. The Fondation Louis Call Vuitton 011in883 0119 or see sassda.co.za. the Bois Du Boulogne, Paris is one of the most remarkable feats of architectural engineering. Your complete stainless information source. What made it possible was the use of structural duplex stainless steel to support the glass sails. As stainless steel is the only man-made noble metal, you’ll see that stainless doesn’t have to be bright to be brilliant.

Stainless Steel. It’s Simply Brilliant.

Callmaterial. 011 883 0119 or see sassda.co.za. tural

Your complete stainless information source.

Frank Gehry’s architecture is unrivalled in its simple complexity. The Fondation Louis Vuitton in the Bois Du Boulogne, Paris is one of the most remarkable feats of architectural engineering. What made it possible was the use of


PROFILE: SASSDA

SASSDA: STAINLESS STEEL & SUSTAINABILITY

F

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o u n d e d i n 1 9 6 4 , t h e S o u t h e r n mak e better choices to reduce the Africa Stainless Steel Development building’s carbon footprint. Association (sassda) is one of the Sassda recently introduced a Life most ac tive stainless steel industr y Cycle Costing ‘app.’ Available now for associations in the world. Its philosophy only ‘android’ use, the ‘app’ will shor tly is one of engagement as it seeks to support all smart devices. increase the use and awareness of The ser vice life prediction necessar y stainless steel. fo r LC A m a k e s c o r ro s i o n - re s i s t a n t , h i g hGehry’s - r e c y c architecture led-content The Association provides a platform l o n g - l i f e , Frank l e s s s te einl its a nsimple o bv icomplexity. o u s c h o i c e, for its members to collectively promote s t aisi nunrivalled The Fondation Louis Vuitton in the the sustainable growth and development par ticularly for corrosive applications. Bois Dusteel Boulogne, Paris isdocumented one of the Stainless provides of the ‘only man-made noble metal. ‘ most remarkable feats with minimal T h e c o n s t r u c t i o n i n d u s t r y i s o f long-term per formance of architectural engineering. no maintenance in a wide range of par ticular interest as it promises high or What made it possible was the use of gro w t h o p p o r t u n i t i e s fo r s t a i n l e s s environments. structural duplex stainless steel s te e l. Th e A rc h i te c t u re, B u i l d i n g & An average of 92 percent of the to support the glass sails. As stainless is the only is used insteel construction Construction Sector of sassda is one of stainless steel man-made noble metal, the largest and most active sectors of recycled into new metal (an indefinitely you’ll see that stainless the Association. Its members understand recyclable resource). doesn’t have to be bright the unique qualities of stainless steel “ The sassda adver tising campaign to be brilliant. and how the range of metals complies pay-off line of ‘Stainless Steel. Its Simply with the ever-increasing requirements Brilliant,’ refers not only to the metal’s of sustainability as defined by the technical and aesthetic brilliance, but International Green Construction Code to its money-saving brilliance,” says John (IgCC) and widely used voluntar y rating Tarboton, sassda Executive Director: Stainless Steel. It’s Simply Brilliant. systems, including Leadership in Energy “ Fo r h e l p f u l a d v i c e o n h o w t o Call 011 883 0119 or see sassda.co.za. and Environmental Design (LEED). capitalise on stainless steel’s unique Your complete stainless information source. S u s t a i n a b i l i t y i s a n i n c re a s i n g l y proper ties, visit our website (w w w. impor tant factor in decision-mak ing. sassda.co.za) or call (+27 11 883 0119).” Whole -building life c ycle assessment (LCA) makes it possible to look at all phases of a building, from material ex traction through construction and decommissioning to rec ycling. When i t c o m e s t o c o m p a r i n g m a t e r i a l s, increasingly available data, an ASTM standard procedure, and LCA analysis software are helping design professionals THE GREEN BUILDING HANDBOOK

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Local Content

supporting local economies Jeremy Gibberd


10

L

ocal content refers to materials and products made in a country as opposed those that are imported. There is an increasing interest in the concept of local content as a means of supporting local economies and providing jobs (Belderbos & Sleuwaegen, 1997; Qiu & Tao, 2001; Corkin, 2012; Warner, 2011; Stephenson, 2013). Local content is also seen a way of improving national sustainability performance and developing greener buildings (Olivier et al, 2016; van Reneen, 2014; Gibberd, 2002). As a result, an increasing number of developed and developing countries are developed procurement policies that promote local content and it is estimated that about 11% of world trade has been affected (Stephenson, 2013). This chapter defines local content and provides examples of this in buildings and construction. It shows how local content targets or local content requirements (LCRs) are being formalised in government policy and pursued in procurement regimes. The relationship between local content and sustainability is also delineated in order to demonstrate the implications of local content on building design, construction and operation. The advantages and disadvantages of local content approaches are discussed and illustrated through examples. Finally, broad recommendations are provided to enable the concept of local content to be more effectively integrated in to buildings and construction. Defining Local Content A comprehensive definition of local content has been developed by Warner. This defines local content as: the composite value contributed to the national economy from the purchase of bought-in goods and services , and includes wages and benefits, materials, equipment and plant, subcontracts and taxes. It also includes first-order, direct economic impacts on the national employees of contractors and

LOCAL CONTENT

suppliers, second-order, indirect impacts on their suppliers and subcontractors and subsubcontractors, and third-order, induced impacts arising as the income earned by nationals and resident workers is spent in the wider domestic economy (Warner, 2011). This definition demonstrates the potential complexity of the concept and shows how it can be interpreted in a number of ways. For instance, local content can be described in terms of the number of national workers employed within a total workforce, or as a proportion of procurement expenditure allocated to local suppliers ( Warner, 2011). A key issue with definitions is how ‘local’ is defined. Again, there are a range of interpretations, with ‘local’ being defined by the extent of shareholding owned by nationals, whether a firm is registered for tax locally, or the extent to which the goods and services provided are locally developed ( Warner, 2011). In geographical terms, ‘local’ in relation to material and product procurement can also mean ‘within the country’, ’within 400km of the construction site’ or ‘within 50km of a construction site’ (van Reneen, 2014). As result of the potential pitfalls in this field, Warner concludes that where the term ‘local content’ is applied, particularly in relation to procurement, its’ precise meaning, and a metric, should always be provided ( Warner, 2011). Local Content Requirements Local Content Requirements, or LCRs, are required levels of local content in materials and products defined within a procurement policy. These are set by government or other role players to support objectives related to economic and growth and employment (Belderbos & Sleuwaegen, 1997; Qiu & Tao, 2001; Corkin, 2012; Stephenson, 2013). LCRs are achieved by being stipulated in procurement policy, tenders and contractual documents. Procurement processes may express preference for domestic suppliers over THE GREEN BUILDING HANDBOOK

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10

LOCAL CONTENT

The South African Federation of Hospital Engineering

SAFHE, is a national multi-disciplinary association for the

promotion and development of healthcare building design and engineering in Southern Africa. Established in 1977,

SAFHE welcomes health planners, managers, nurses, doctors, architects, engineers, quantity surveyors and project managers from both public and private sectors into a community of practice.

SAFHE

is a national multi-disciplinary voluntary association. SAFHE is registered with the Engineering Council South Africa (ECSA)

SAFHE is conngured into regional branches, with a membership totalling over 500 and programmes geared to local interests. Talks, seminars, discussions and workshops take place regularly on a variety of subjects. SAFHE promotes and develops better healthcare building design

and engineering

SAFHE is an â&#x20AC;&#x153;Aâ&#x20AC;? member of the International Federation of Hospital Engineering and has participated extensively in Council meetings, including serving on its Executive Committee.

162

www.safhe.co.za

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For more details visit:


10 foreign suppliers through domestic only tender lists, price advantages or through specific tender clauses. While preference for local providers may be expressed, care should be taken to avoid protectionism, and local content provisions should only advantage domestic suppliers ‘when all else is equal’ (Warner, 2011a). In this way, healthy competition is preserved (Warner, 2011a). This principle can be illustrated through bid and tender documentation clauses illustrated below: Government / the Company shall, when purchasing goods and services required with respect to Buildings and Construction, give first preference, at comparable quality, delivery schedule and price, to goods produced in [COUNTRY] and services provided by [COUNTRY] citizens or businesses, subject to technical acceptability and availability of the relevant goods and services in [COUNTRY] (adapted from Warner, 2011a). And: Give preference to local contractors and locally manufactured materials and products as long as their performance, quality and time of delivery are competitive with international performance and prices (Warner, 2011a) Local Content in South Africa The South African government has pursued local content requirements through procurement policy that ensures that government, as a ‘large buyer’, supports local production. The detail of the approach is set out in the Industrial Policy Action Plan (IPAP) (DTI, 2013) Industrial Policy Action Plan 2013/2014 – 2015/2016 The goal of the Industrial Policy Action Plan (IPAP)’s is to support growth and diversification of the manufacturing sector in South Africa (DTI, 2013). In particular, it aims to ensure that manufacturing generates significant jobs and supports economic activity in associated service sector industries (DTI, 2013). The IPAP

LOCAL CONTENT

provides for procurement policy levers to support local manufacturing including: • Designations for local procurement; • Deepening of localisation in the large fleet procurement processes of State-Owned Companies (SOCs); • Localisation in the renewable energy generation programme; and • Increasing acceptance and implementation of localisation targets across the spectrum of state procurement regimes (DTI, 2013) To 2.3 maximise support of domestic Industrial Policy Action Plan 2013/2014 – 2015/2016 The goal of the Industrial Policy Action Plan (IPAP)’s is to support growth and diversification of the manufacturing in South Africa (DTI, 2013). Inof particular, it manufacturing, thesectorDepartment Trade aims to ensure that manufacturing generates significant jobs and supports economic in associated service sector industries (DTI, 2013). The IPAP provides for andactivity Industry (DTI) has designated procurement policy levers to support local manufacturing including: minimum • Designations local procurement; thresholds forforlocal content in a range materials • Deepening of localisation in the large fleet procurement processes of StateOwned Companies (SOCs); and products procured by government (DTI, • Localisation in the renewable energy generation programme; and Increasing acceptance and implementation ofshown localisation targets the 1. 2013).• These thresholds are in across table spectrum of state procurement regimes (DTI, 2013) Table 1: Industries, sectors and sub-sectors To maximise support of domestic manufacturing, the Department of Trade and Industry (DTI) has designated minimum thresholds for local content in a range materials and products government (DTI, 2013).with These thresholds are designated for procured localbyproduction minimum shown in table 1. localTablecontent thresholds (DTI, 2013) 1: Industries, sectors and sub-sectors designated for local production with minimum local content thresholds (DTI, 2013) Industry/sector/sub-sector

Minimum threshold for local content

Buses (Bus Body) Textile, Clothing, Leather and Footwear Steel Power Pylons, Monopole Pylons, Steel Substation Structures, Powerline Hardware, Street Light Steel Poles, Steel Lattice Towers Canned / Processed Vegetables Pharmaceutical Products: •

OSD Tender

Family Planning Tender

80% 100%

100%

80% 70% (volumes) 50% value

Rail Rolling Stock Set Top Boxes (STB) Furniture Products:

65% 30%

Office Furniture

85%

School Furniture

100%

Base and Mattress

Solar Water Heater Components Electrical and telecom cables Valves products and actuators Residential Electricity Meter :

90% 70% 90% 70%

3

Prepaid Electricity Meters

70%

Post Paid Electricity Meters

70%

SMART Meters

50%

Working Vessels/Boats (All types): •

60%

Components

10% - 100%

Conveyance Pipes Transformers and Shunt Reactors:

80% - 100%

Class 0

90%

Class 1

70%

Class 4

Components and conversion activities

10% 50% - 100%

Therefore, within the sectors outlined in table 1, the public sector is required to include, as a specific tendering condition, that only locally produced goods, services or works with the stipulated minimum threshold for local production and content may be considered.

Therefore, within the sectors outlined in table Public bodies may also specify local content requirements where products are not designated, so long as these do not contradict DTI and Treasury directives. Public 1, the public is required to include, bodies are defined as allsector national and provincial departments, all municipalities, all entities listed in terms of Schedules 2 and 3A and 3B as well as all other government (DTI, 2013) as aagencies and State Owned Companies are required specific tendering condition, that only 2.4 Measuring Local Content locally produced goods, services or works with Local content in South African government procurement is defined in accordance with SATS 1286, a standard developed of the South African Bureau of Standards (SABS) (SABS, the 2011). This standard defines local content as: stipulated minimum threshold for local ‘that portion of goods, works and services that have been generated and produced in South production and content may be considered. Africa. Companies that import raw material and convert this raw material in South Africa .

also contribute to local content to the extent that the South African value-added processes and additional inputs count as Local Content’ (SABS, 2011). Local content (LC) in the procurement processes is calculated in the Standard as as a percentage of the bid price in accordance with the following formulae: LC = 1 Where

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LOCAL CONTENT

10

Public bodies may also specify local content requirements where products are not designated, so long as these do not contradict DTI and Treasury directives. Public bodies are defined as all national and provincial departments, all municipalities, all entities listed in terms of Schedules 2 and 3A and 3B as well as all other government agencies and State Owned Companies are required. (DTI, 2013) Measuring Local Content Local content in South African government procurement is defined in accordance with SATS 1286, a standard developed of the South African Bureau of Standards (SABS) (SABS, 2011). This standard defines local content as: ‘that portion of goods, works and services that have been generated and produced in South Africa. Companies that import raw material and convert this raw material in South Africa also contribute to local content to the extent that the South African valueadded processes and additional inputs count as Local Content’ (SABS, 2011). Local content (LC) in the procurement processes is calculated in the Standard as as a percentage of the bid price in accordance with the following formulae: LC = 1 x 100 Where x imported content y bid price excluding value added tax (VAT ) Confirmation of local content (LC) may be required in bids for government work and is achieved through completing form SBD 6.2 of the Standard Bidding Documents (SABS, 2011). Local Content in Green Building Rating Systems Local content is also targeted in a number of green building rating systems. The Greenstar rating tool, adapted for South Africa, for instance, includes a ‘Local Sourcing’ criterion which aims to reduce transport emissions

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associated with the transportation of building materials and products (GBCSA, 2016). This recognises the extent to which materials and products used in a building are sourced within 50km or 400km of a building site (GBCSA, 2016). The LEED green building rating system developed in the USA similarly recognises local content in the ‘Responsible Sourcing of Raw Materials’ criterion. This encourages the selection of materials that have ‘environmentally, economically, and socially preferable life cycle impacts’ and includes credit for materials that are sourced (extracted, manufactured, and purchased) within 160 km of the project site (USGBC, 2009) Examples of Local Content in Buildings The procurement of local products and materials has been identified as an important way for supporting local economic growth in many countries (Stephenson, 2013). However, while a number of countries have put in place robust local content laws, their effective implementation has not always been successful (Corkin, 2012). This may be because local content has not been explicitly targeted. It may also be a result of existing design and construction practices which do not support local content considerations. This may be illustrated through two building examples. In this section, two building examples are presented and compared in terms of local content of materials and products. The projects presented are houses that were built with almost identical briefs, budgets and construction timeframes. Both buildings were also constructed in suburban locations by small contractors during the same period. A key difference in the projects is that local content was specifically targeted in one building and not the other. The projects and the materials and products used in their construction are outlined below.


10

LOCAL CONTENT

Building A (Low local content) Figure one shows building A where local content was not targeted.

Figure 2: Building B (High local content) Figure 1: Building B (low local content)

The materials and products labelled in figure 1, is provided below. 1. Roof materials: Impor ted pressed aluminium roof sheeting. 2. Roof structure: Imported steel trusses are used for the roof structure. These were specified instead of local timber trusses as a result of concerns about the quality of locally manufactured timber trusses. 3. Ceiling: I mpor ted pressed steel ceiling panels. Ceiling installation was subcontracted to a ceiling subcontractor who used imported pressed steel ceiling panels. 4. Light and electrical fittings: Imported light and electrical fittings. The electrical subcontractor used imported light and electrical fittings. 5. Kitchen units: Imported Medium Density Fibreboard (MDF) kitchen units. 6 . Wi n d ow s : I m p o r te d a l u m i n i u m windows. 7. Doors: Imported pressed steel doors. 8. Flooring: Imported tiles. 3.2 Building B (high local content) The building B is shown in figure 2 and specifically targeted local content.

The materials and products labelled in figure 2, is provided below. 1 . R o o f m a t e r i a l s : C o n c re t e t i l e s manufactured in the country. 2 . R o o f s t r u c t u re : T i m b e r t r u s s e s manufac tured in the countr y from sustainably managed forests within the country. A reputable local supplier and construction super vision was used to ensure good quality construction. 3. Ceiling: Plasterboard ceilings manufactured within the country. 4. Light and electrical fittings: Electrical fittings manufactured within the country. 5. Windows and doors: Hardwood timber windows and doors manufactured within the country. The timber used is sourced within the country from locally grown, sustainably managed forests. 6.Walls: Compressed earth blocks. Wall materials were developed using material excavated on site. Review of examples A review of the two examples can be used to discuss the implications of the materials and product choices on the local economy, people and building performance. THE GREEN BUILDING HANDBOOK

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LOCAL CONTENT

10

Local economy The imported materials and products in Building A provide very little employment for importers, suppliers and transportation companies in the country (the importing country). However, the use of local materials and components, such as locally grown and manufactured windows and doors in Building B creates significant levels of direct employment with the country. It also creates indirect impacts in associated enterprises, such as forestry and timber processing companies where additional economic activity and jobs are supported. Increased local revenue streams achieved through purchasing local goods can be used for training and improved machinery and infrastructure, leading to better local products in the long term. Salaries from jobs created by local businesses, in turn, can be pay for improved education and health, leading to increased economic competitiveness and productivity. Repairs and replacement Where components, such as electrical fittings or tiles, fail or break, it may be difficult to replace, or repair these, if products are imported. This can result in significant waste as wholesale replacement of components may be required. For instance, if replacement tiles cannot be sourced for tiles in Building A, this may lead to the removal and replacement of tiles for the entire floor – even if only one or two tiles are damaged. Specifying local materials, such as tiles, can help ensure that replacement components are easily sourced. This helps prolong the life of components and reduce waste and costs associated with refurbishment. Health and safety The imported products in Building A may not align with good practice health and safety standards or local regulations. For instance, imported electrical fittings may not comply with local regulations and imported kitchen units may include levels of formaldehyde content which are harmful for human health.

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Local products may also not comply with good practice standards, however, incentives, penalties and support can be more easily brought to bear on local manufacturers to improve practice. In addition, compliance with local regulations and best practice health and safety standards can be more readily confirmed through local certification and checks (for instance, through factory visits). Thermal performance The high thermal conductivity of the imported roofing material, trusses and ceiling panels, installed without additional insulation in Building A results in significant heat flows through the building envelope potentially leading to discomfort and poor energy efficiency. Levels of heat flow through the building envelope in Building B is reduced, as concrete tiles, timber trusses and plaster ceilings have higher thermal mass and reduced thermal conductivity. Thus, in terms of thermal performance, the ‘heavier’ local materials used in the Building B have a distinct advantage over the ‘lighter’ imported materials in Building A and therefore has the potential to support improved energy efficiency and occupant comfort. Discussion A critical analysis of definitions, the building examples, and literature can be used to discuss the implications, as well as the advantages and disadvantages of targeting local content in building materials and product procurement. Quality Locally manufactured materials and products may not achieve the same levels of quality as imported goods. This may be caused by limitations in local skills and equipment (Warner, 2011). Where this is the case, it is important to address this by enabling local manufacturers to access training and improved equipment. In South Africa, access to funding


10 for these activities can be accessed from the Industrial Development Corporation (IDC) (IDC, 2016). Quantity Local manufacturers may not be able to produce materials and goods in the quantities required for fast track, large-scale, projects (Corkin, 2012). Avoiding this situation requires planning and the incorporation of lead-in times to enable local manufacturers to scale-up production and stockpile materials and products required for large projects. (Warner, 2011) Competition Limited competition may result in locally manufactured materials and products being more expensive and being unresponsive to market needs (Belderbos & Sleuwaegen, 1997). This can be avoided by ensuring that there is healthy competition in the local manufacturing industry. Increased competition can be enhanced through support which ensures that monopolies are avoided (IDC, 2016, Warner, 2011). Embodied energy Embodied energy refers to the energy consumed by all of the processes associated with the production of a building, from the mining and processing of natural resources to manufacturing, transport and product delivery (Milne, 2013). Reducing the distance materials and products are transported lowers the embodied energy of materials and products used in buildings. Therefore, locally sourced materials and products have a lower embodied energy content than similar imported materials (Morel et al, 2001). Transport impacts Large-scale transportation of materials and products, particularly if vehicles are used, has a range of negative impacts. These include consumption of fossil fuels, noise and air pollution, and road accidents. Sourcing materials and products locally enables

LOCAL CONTENT

negative transport impacts to be avoided, or reduced (Venkatarama et al, 2003). Negative impacts of local production Processing materials and the manufacture of products may result in pollution and waste. Closer proximity between production and consumption of materials and products means that the negative impacts of production are likely to be experienced by consumers of these materials and products (Gibberd, 2002). This can be beneficial, as consumers become more discerning about the products and materials they use and put pressure on manufacturers to reduce, or avoid, negative impacts associated with the manufacture of products. This â&#x20AC;&#x2DC;local accountabilityâ&#x20AC;&#x2122; is a valuable way of means of achieving more environmentally friendly products and manufacturing processes (Ekins et al, 1992). Local employment Local production of materials and products supports local business and creates employment ( Takechi & Kiyono, 2003). Increased income and tax revenue from these businesses can be used to improve education and health leading to improving quality of life and increased economic competitiveness (Gu, 2003). Economic diversity Buildings require a wide range of different materials and components in their construction. This diversity can be used to develop a wide range of small enterprises linked to, for instance, door and window, tile, paint, roof truss, brick and furniture and fittings manufacture. The resulting local economic diversity is more resilient and better able to weather economic downturns compared to situations where there is only one or two large employers (Ahern, 2011; Ekins et al, 1992). Maintenance and repairs Manufacturing products locally means that the skills and materials used to produce these THE GREEN BUILDING HANDBOOK

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LOCAL CONTENT

10

products are likely to be available locally in the long-term and are available to carry out repairs and maintenance. This enables repairs and maintenance to be carried out more quickly and cost effectively as waiting time and costs associated with imported products are avoided. Reduce operational downtime and improved efficiencies can therefore be achieved (Warner, 2011). Product development A closer physical relationship between product manufacturers and the installation, and use, of their products can result in improved product development processes and more appropriate products as designers are more aware of how their products are used. In addition, in the case of specialist, or more complex products, manufacturers are also able to visit sites and advise on installation and commissioning. This leads to better products and improved installation and commissioning. Local product development is also more likely to understand, and align with national standards and legislated requirements thereby reducing risks of non-compliance (Warner, 2011). Risk and supply chains By avoiding transport logistics and bureaucracy, such as import permits, related to the importation of goods, local product manufacturers can reduce delivery times and improve the predictability of supply. Local quantities of product stocked at building suppliers can also be reduced as additional stock can be more easily ordered and delivered (Warner, 2011). Foreign exchange Imported materials and products have to be paid with foreign exchange. In some developing countries foreign exchange may be limited and be required for imported products that cannot be produced locally such as medical or energy generation equipment (Nortje, 2016). In this

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situation, using local products and materials for buildings frees up valuable foreign exchange for vital technology and equipment that may not have been imported otherwise. Conclusions and Recommendations The review indicates that business and government can improve the sustainability performance of buildings, create jobs and support the local economy by specifying local materials and products in buildings. Local content procurement is also relatively easy to implement, making it an ideal way of stimulating the local economy and creating more sustainable buildings. However local content still has not been pursued widely as an objective in building product specification or been successfully implemented in construction (Corkin, 2012). The following recommendations are therefore made to support its increased adoption. • Local Content Certification: An effective methodology for defining local content of local building materials and products should be established. Certification based on this methodology should be offered to local manufacturers of building materials and components at no, or very low, cost. • Local Content Promotion: Building materials and products that have full, or very high, levels of local content should be promoted through branding, publicity and databases that building product specifiers, such as Architects, can easily access. • Local Content Calculators: Simple calculators should be developed to support Local Content calculations. These could draw data from Bills of Quantities developed by Quantity Surveyors to develop accurate estimates of local content for entire buildings or building assemblies such as the roof, or electrical and wet services systems. • Local Content Targets: Specific targets for local content should be defined by government and businesses for different building types and achievement of these targets required in professional appointments. Targets can also be specified


10 in standard specifications, such as those used by Public Works (Public Works, 2014). Targets should be monitored during design and construction to ensure that they are achieved. Evidence of the achievement of local content targets can be confirmed through Local Content Certification and Local Content Calculations (see above). â&#x20AC;˘ Local Content Development: Where the availability of high local content materials

LOCAL CONTENT

and products is limited, additional support to manufacturers in these fields should be explored. This can be provided through financial support, technical expertise and access to high quality equipment and materials. Ensuring a range of efficient local manufacturers exist within the key building component areas will help ensure that high quality and competitively priced locally products are produced.

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10

References

• Ahern, J, 2011. From fail-safe to safe-to-fail: Sustainability and resilience in the new urban world. Landscape and Urban Planning, 100(4), 341–343. • Belderbos, R, & Sleuwaegen, L, 1997. Local Content Requirements and Vertical Market Structure. European Journal of Political Economy, 13(1), 101–119. • Corkin, L, 2012. Chinese construction companies in Angola: A local linkages perspective, Resources Policy 37, 475–483. • DTI, 2013. Industrial Policy Action Plan 2013/2014 – 205/2016, Accessed from https://www.thedti.gov.za/ editmedia.jsp?id=2609) • Ekins, P, Hillman, M, Hutchison, R, 1992. Wealth beyond Measure: an Atlas of new Economics, Doubleday, New York. • GBCSA, 2016. Greenstar Office Tool. Accessed from https://www.gbcsa.org.za/green-star-rating-tools/ office-rating-tool/ • Gibberd, J, 2002. The Sustainable Building Assessment Tool: Assessing How Buildings Can Support Sustainability in Developing Countries, Built Environment Professions Convention, 1 – 3 May 2002, Johannesburg, South Africa • Gu, W, & Yabuuchi, S, 2003. Local content requirements and urban unemployment. International Review of Economics and Finance, 12(4), 481–494. • IDC, 2016. Our Products, Industrial Development Corporation. Accessed from http://www.idc.co.za/ home/idc-products.html • Milne, G, 2013. Embodied Energy. Accessed from http://www.yourhome.gov.au/materials/ embodied-energy) • Morel, J, C, Mesbah, A., Oggero, M, & Walker, P, 2001. Building houses with local materials: Means to drastically reduce the environmental impact of construction. Building and Environment, 36(10), 1119–1126. • Nortje, B, 2016. Zimbabwe’s unavoidable truth. Businessday, Accessed from http://www.bdlive.co.za/ opinion/columnists/2016/06/09/zimbabwes-unavoidable-truth • Public Works, 2014. Construction Specifications, Accessed from http://www.publicworks.gov.za/consultantsguidelines.html • Qiu, L, D, & Tao, Z, 2001. Export, foreign direct investment, and local content requirement, Journal of Development Economics, 66(1), 101–125. • SABS, 2011. Local Goods, Services and Works – Measurement and Verification of Local Content, SATS 1286: 2011. • Stephenson, S, 2013. Addressing Local Content Requirements in a Sustainable Energy Trade Agreement. International Centre for Trade and Sustainable Development, Accessed from http://www.ictsd.org/ downloads/2013/06/addressing-local-content-requirements_opt.pdf

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10

LOCAL CONTENT

• Takechi, K, & Kiyono, K, 2003. Local content protection: Specific-factor model for intermediate goods production and market segmentation, Japan and the World Economy, 15(1), 69–87. • USGBC, 2009. Responsible sourcing of raw materials. Accessed from http://www.usgbc.org/credits/ new-construction-core-and-shell-schools-new-construction-retail-new-construction-healthcar-7 • Van Reenen, C, 2014. Principles of material choice with reference to the Green Star SA rating system. In: Green Building Handbook, South Africa: Volume 7: Materials and Technologies, 42-51 • Venkatarama Reddy, B, V, & Jagadish, K, S, 2003. Embodied energy of common and alternative building materials and technologies, Energy and Buildings, 35(2), 129–137. • Warner, M, 2011. Local Content in Procurement: Creating Local Jobs and Competitive Domestic Industries in Supply Chains. Sheffield, South Yorkshire, GBR: Greenleaf Publishing. • Warner, M, 2011a. Do Local Content Regulations Drive National Competitiveness or Create a Pathway to Protectionism?, Accessed from www.localcontentsolutions.com

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Specifying for Superior Thermal Performance with wall constructions energy efficiency in building standards

Peter Kidger, Corobrik


11

Acknowledgements:

The contribution of research study information and reports by researchers at the University of Pretoria Department of Architecture, the University of Newcastle Priority Research Centre for Energy, Energetics (Pty) Ltd, WSP Green by Design, WSP Energy Africa, SP Energy and Structatherm Projects, with kind permission of the Clay Brick Association of South Africa and Think Brick Australia. Introduction: With both high mass masonry and low mass alternate building technology wall construction types and their different combinations of thermal mass and resistance satisfying the minimum requirements of SANS 10400 Part XA Building Regulations and the ‘Deemed to Satisfy’ SANS 204 Energy Efficiency in Buildings Standards (prescriptive and voluntary), this Chapter sets out to identify which of the wall construction types in compliance with the SANS 10400 Part XA Building Regulations and SANS 204 Energy Efficiency Standards are the more thermally competent for dealing with the challenges of South Africa’s dynamic external environments and delivering the lowest heating and cooling energy usage and cost over the lifecycle. 2. Compliance Requirements in the SANS 10400 Part XA Building Regulations and SANS 204 Energy Efficiency in Buildings Standards: 2.1’Deemed to Satisfy’ prescriptive requirements in SANS 10400 Part XA and SANS 204: The SANS 10400 Part XA Building Regulations and SANS 204 Energy Efficiency in Building Standards for non-masonry buildings set minimum levels of resistance (R-values) for masonry and non-masonry wall constructions to comply. Compliance for masonry walls requires the wall to have a minimum wall R-value of R0.35 for each of the six major climatic zones. Alternate Building Technology lightweight wall constructions on the other hand, require

SUPERIOR THERMAL PERFORMANCE

minimum wall R-values of R2.2 for Climatic Zones 1, 3, 4 and 6 and R1.9 for Climatic Zones 2 and 5. In the case of masonry walling a minimum wall R-value R0.35 relates to 140mm ‘through the wall’ concrete block wall construction. Typically, 220mm Solid Double Brick walls have a wall R-value of R0.45 and a 270mm Cavity Brick a wall R-value of R0.60 both exceeding the minimum prescriptive wall R-value for masonry buildings. 2.2 Voluntary requirements in the SANS 204 Energy Efficiency in Building Standards: The ‘Deemed to Satisfy’ SANS 204 Energy Efficiency in Building Standards for masonry building (presently voluntary) recognises that the resistance (R-value) of a walling material to heat flow is important for achieving energy efficient buildings. At the same time it also recognises that R-value is not the all-important thermal performance property of a walling material for moderating amplitude ratios, facilitating thermal comfort and advancing energy efficiency of buildings in South Africa’s different climates. Notably, it recognises that thermal capacity of clay brick walls to absorb a large quantity of heat energy for a small rise in temperature combined with the thermal lag, in effect increases the R-value performance of masonry walls. It recognises that double brick walls, with added insulation in the cavity appropriate to the climatic zone, provides double brick walls with added resistance to reduce heat loss in winter without compromising the active thermal capacity on the inside. Thermal capacity on the inside functions to temper indoor climates to within the required comfort range in both summer and winter leading to the maximization of energy efficiencies in support of the energy reduction targets set out in the RSA energy strategy. The ‘Deemed to Satisfy’ SANS 204 Energy Efficiency in Building Standards for masonry building (voluntary) thus sets the combinations THE GREEN BUILDING HANDBOOK

173


11

SUPERIOR THERMAL PERFORMANCE

of Thermal Capacity (C), as derived from the thermal mass of clay brick walls, and Resistance (R) as derived from the bricks themselves, the air between the brick skins and any added insulation, referenced as the ‘CR Product’ of the wall, for meeting South Africa’s energy efficiency targets for different building typologies in each of the six major climatic zones. The CR Product is the time constant property (hours) of a composite element, being the arithmetical product of the total C-value (kJ/m 2 K) and total R-value (m 2 K/W ), where total C-value is the sum of the component C-values of individual component layers in a composite element including the airspace. Table 1 below sets out the minimum CR Product values (in hours) masonry walls require for compliance in the different occupancy building groups. Table 1 – Minimum Thermal Capacity & Resistance CR Product, in hours, for external masonry walling Occupancy group Residential E1-3,H1-5 Office & Institutional A1-4,C1-2,B1-3,G1 Retail D1-4, F1-3,J1-3 Unclassified A5, J4

1 100 80 80 NR

2 80 80 80 NR

Climatic zone 3 4 80 100 100 100 120 80 NR NR

5 60 80 60 NR

6 90 80 100 NR

NOTE NR = No requirement

2.2.1 Composite Masonry Wall CR Products – Residential Buildings:

2.2.1 Composite Masonry Wall CR To achieve the required wall CR Product for Residential buildings, adding insulation R0.5 in Products – Residential Buildings: the cavity between the brick skins provides a CR Product of 90 facilitating compliance for To achieve the required wall CR Product Climatic Zones 2(80), 3(80) & 6(90). Including insulation R1.0 in the cavity provides a CR Product of 130, this in excess of the minimum CR Product requirement for Climatic Zones 1 for Residential buildings, adding insulation & 4 (100). Cavity Brick has a CR Product of 60 and therefore no insulation is required in the R0.5 in the cavity between the brick skins cavity for compliance in Climatic Zone 5. provides a CR Product of 90 facilitating compliance for Climatic Zones 2(80), 3(80) & 2.2.3 Composite Masonry Wall CR Products – Offices & Institutional Buildings: 6(90). Including insulation R1.0 in the cavity In the case of Office and Institutional buildings, including additional insulation R0.5 between provides a CR Product of 130, this in excess the brick skins provides a CR Product of 90 facilitating compliance for Climatic Zones 1, 2, 5 of the minimum CR Product requirement for & 6 (80). Including insulation R1.0 facilitates a CR Product of 130 effecting compliance for Climatic Zones 3 & 4 (100). Climatic Zones 1 & 4 (100). Cavity Brick has a CR Product of 60 and therefore no insulation is required in the cavity for compliance in 3. Identifying the most thermally competent wall construction types: Climatic Zone 5. In identifying which of the high and low mass wall construction types are the more thermally competent for lowering energy usage, this Chapter interrogates the findings of the 2015 University of Pretoria thermal modelling study (TPS), ‘A Thermal Performance THE GREEN BUILDING HANDBOOK 174 Comparison Between Six Wall Construction Methods Frequently Used in South Africa’,

2.2.3 Composite Masonry Wall CR Products – Offices & Institutional Buildings: In the case of Office and Institutional buildings, including additional insulation R0.5 between the brick skins provides a CR Product of 90 facilitating compliance for Climatic Zones 1, 2, 5 & 6 (80). Including insulation R1.0 facilitates a CR Product of 130 effecting compliance for Climatic Zones 3 & 4 (100). 3. Identifying the most thermally competent wall construction types: In identifying which of the high and low mass wall construction types are the more thermally competent for lowering energy usage, this Chapter interrogates the findings of the 2015 University of Pretoria thermal modelling study (TPS), ‘A Thermal Performance Comparison Between Six Wall Construction Methods Frequently Used in South Africa’, Department of Architecture, University of Pretoria, (Vosloo P., Harris H., Holm D., van Rooyen N., Rice G., April 2015) [1], in respect of the heating and cooling energy usage of three building typologies located in South Africa’s six major climatic zones. The accuracy of the University of Pretoria TPS findings is validated through: • Their correlation with the findings of ten years of Empirical research at the University of Newcastle, Australia, Priority Research Centre for Energy, into the comparative thermal performance of building modules comprising different Australian wall construction types [2, 3 & 4]. • Their correlations with the findings of four thermal modelling studies (3 South African and 1 Australian) [5, 6, 7 & 8] that used ASHRAE Standard 140 compliant modelling software. • The findings of a critical review of different thermal modelling software [9, 10, 11 & 12], done as part of the University of Pretoria TPS, where DesignBuilder EnergyPlus modelling software, as applied in the TPS,


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SUPERIOR THERMAL PERFORMANCE

was assessed to provide the most accurate energy usage of buildings comprising different wall construction types exposed to the dynamic external conditions. 4. University of Pretoria Thermal Modelling Study ‘TPS’ findings in respect of the comparative thermal performance of frequently used SA wall construction types applied to different building types: The thermal modelling study TPS (1), done as input to the University of Pretoria full LCA of Clay Brick and that has passed critical review, modelled frequently used wall construction types in compliance South African Building Regulations SANS 10400 Part XA and SANS 204 Energy Efficiency Standards applied to three different building typologies – a 2000m2 • Their correlations with the findings of four thermal modelling studies (3 South African and 1 Australian) [5, 6, 7 & 8] that used ASHRAE Standard 140 compliant day-time occupancy Office/Institutional modelling software. • The findings of a critical review of different thermal modelling software [9, 10, 11 & type building, a 40m2Low Cost House and a 12], done as part of the University of Pretoria TPS, where DesignBuilder EnergyPlus modelling software, as applied in the TPS, was assessed to provide the most accurate 130m 2Standard House. energy usage of buildings comprising different wall construction types exposed to the dynamic external conditions.

4.1 Gross annual heating and cooling 4. University of Pretoria Thermal Modelling Study ‘TPS’ findings in respect of the comparative thermal performance of frequently used SA wall construction types applied energy usage of a 2000m² Office/ to different building types: Institutional day-time (12 hours) The thermal modelling study TPS (1), done as input to the University of Pretoria full LCA of Clay Brick and that has passed critical review, modelled frequently used wall construction occupancy building: types in compliance South African Building Regulations SANS 10400 Part XA and SANS 204 Energy Efficiency Standards applied to three different building typologies - a 2000m² daytime occupancy Office/Institutional type building, a 40m² Low Cost House and a 130m² Standard House.

Table 2 – Gross annual heating and cooling energy for 2000 mOffice Building in each 4.1 Gross annual heating and cooling energy usage of a 2000m² Office/Institutional daytime (12 hours) occupancy building: climate zone expressed in kWh The findings in Table 2 above show clay brick Table 2 - Gross annual heating and cooling energy for 2000 m² Office Building in each climate zone expressed in kWh

Climatic Zone

Wall Types 1

220mm Solid Clay Brick

01

02

03

Bloemfontein

51088

04

05

06

Pretoria

Musina

Cape Town

Durban

Upington

82892

222937

67032

140756

190548

270mm Cavity 2

(50mm) Clay Brick

52630

87268

228858

71218

148191

192934

56178

93772

236063

78817

158572

197806

68921

117083

250258

105389

180980

209769

34.9%

41.2%

9.1%

57.2%

40.2%

10.1%

with NO insulation 280mm Cavity 3

(50mm) Clay Brick with insulation

4

Light Steel Frame to SANS 517 LSF to SANS 517 is less energy efficient than 220mm Solid Clay Brick

wall constructions in compliance with SANS 10400 Part XA Building Regulations (220mm Solid Double Brick and 270mm Cavity Brick) and SANS 204 Energy Efficiency Standards (280mm Insulated Cavity Brick with Insulation) significantly more energy efficient than LSF

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specified SANS 517 in all six climatic zones with 220mm Solid Double Brick being the best performer with 270mm Cavity Brick a close second. LSFB lightweight wall construction specified to SANS 517 used on average 23.5% more heating and cooling energy compared to that of the 220mm Solid Double Brick across the six Climatic Zones. In the six climatic zones, LSF specified SANS 517 compared to 220mm Solid Clay Brick, used: • 34.9% more energy in Climatic Zone 1 • 41.2% more energy in Climatic Zone 2 • 12.3% more energy in Climatic Zone 3 • 57.2% more energy in Climatic Zone 4 • 28.6% more energy in Climatic Zone 5 • 10.1% more energy in Climatic Zone 6 The findings highlight Thermal Capacity (C) as the key thermal performance property for achieving ‘superior’ thermal efficiency in day-time occupancy office/institutional type buildings in all six major climatic zones. As shown applying insulation in masonry walls of day-time occupancy buildings to advance energy efficiency across is an unnecessary cost. These findings correlate with those from the University of Newcastle empirical research [2 & 3] that demonstrated that the superior performance of clay brick external walls (220mm Solid Double Brick and 270mm Cavity Brick) is consequent to the thermal mass of the bricks facilitating the necessary thermal lag (approximately 6 hours). Thermal lag of 6 hours results in the sun’s heat passing through the wall only impacting on the inside after the hottest parts of summer days have passed. LSF Insulated lightweight walls on the other hand, have no thermal mass to provide the necessary thermal lag, this leading to the solar heat gain impacting on the inside well ahead of the hottest parts of summer days with the high R-value insulated lightweight walls then trapping the heat inside. The heat flux on the inside coincides with the hottest parts of days outside resulting in the highest cooling energy usage during summer months to maintain thermal


11

• 81.2% more energy in Climatic Zone 4 • 82.1% more energy in Climatic Zone 5 • 7.9 % more energy in Climatic Zone 6 The 6.7% lower energy usage of the 40m 2 LSF house compared to the Cavity Brick house in Climatic Zone 1 is more than reversed with the addition of insulation (R1.0) between the brick skins. In this regard, the study found the LSF house specified to SANS 517 in compliance with SANS 204 (R2.2) uses 90.5% more heating and cooling energy than the SANS 204 compliant Insulated Cavity Brick house in Climatic Zone 1. On average for the six climatic zones the SANS 204 compliant LSF specified to SANS 517 consumes 162.3% more heating and cooling energy than the SANS 204 compliant Insulated Cavity Brick walled 40m² house. Looking at the different climatic zones LSF specified to SANS 517, compared to the 280mm Insulated Cavity Brick house, used: • 90.5% more energy in Climatic Zone 1 • 185.5% more energy in Climatic Zone 2 • 56650.0% more energy in Climatic Zone 3 • 298.2% more energy in Climatic Zone 4 • 179.4% more energy in Climatic Zone 5 • 65.1 % more energy in Climatic Zone 6

comfort conditions of air-conditioned lightweight walled buildings. In the case of the institutional building such as school classrooms however, that rely on natural ventilation rather than air-conditioning to manage internal thermal comfort during day-time hours, internal temperatures of LSF classrooms escalate to that of a ‘hot-box’ for extended periods on summer days presenting the most challenging teaching and learning environments. 4.2 Gross annual heating and cooling energy usage of a 40m2 house: Table 3 – Gross annual heating and cooling energy for 40 mhouse in each climate zone expressed in kWh Table 3 - Gross annual heating and cooling energy for 40 m² house in each climate zone expressed in kWh

Climatic Zone

Wall Types 1

220mm Solid Clay Brick

01

02

03

04

05

06

Bloemfontein

Pretoria

Musina

Cape Town

Durban

Upington

1464

1055

1282

734

590

2428

1009

725

887

479

454

1904

496

379

2

218

296

1244

945

1082

1135

868

827

2054

270mm Cavity 2

(50mm) Clay Brick with NO insulation 280mm Cavity

3

(50mm) Clay Brick with insulation

4

Light Steel Frame to SANS 517

As shown in Table 3 of the gross heating and cooling of a 40m² house, 220mm Solid Double Brick walling (R0.45) is more energy efficient all-day (24 hours) than LSF specified to SANS

517 in three of the six climatic zones (2.5% more in Zone 2 - Pretoria, 15.4% more in Zone 4 - AsCape Town and 28.7% more in Zone 5 - Durban). shown in Table 3 of the gross heating 270mm Cavity Brick in compliance with SANS 10400 Part XA Building Regulations with its and cooling of a 40m 2 house, 220mm higher wall R-value (R0.60) to that of 220mm Solid Double Brick (R0.45), is generally (26.6%) more energy efficient than LSF specified to SANS 517 across the six Climatic Zones. Solid Double Brick walling (R0.45) is more LSF specified to SANS 517, compared to the 270mm Cavity Brick house, used: energy efficient all-day (24 hours) than • 6.7% less energy in Climatic Zone 1 49.2% more energy in Climatic Zone 2 LSF• specified to SANS 517 in three of the • 27.9% more energy in Climatic Zone 3 81.2% more energy in Climatic Zone 4 six ••climatic zones (2.5% more in Zone 2 82.1% more energy in Climatic Zone 5 • 7.9 % more energy in Climatic Zone 6 – Pretoria, 15.4% more in Zone 4 – Cape The 6.7% lower energy usage of the 40m² LSF house compared to the Cavity Brick house in Town and 28.7% more in Zone 5 – Durban). Climatic Zone 1 is more than reversed with the addition of insulation (R1.0) between the

4.3 Gross annual heating and cooling • 90.5% more energy in Climatic Zone 1 energy of a 130 m 2 house: • 185.5% more energy in Climatic Zone 2

brick skins.

In this regard, the study found the LSF house specified to SANS 517 in compliance with SANS

204 (R2.2) uses 90.5% more heating and cooling energy than the SANS 204 compliant 270mm Cavity Brick in compliance with Insulated Cavity Brick house in Climatic Zone 1. SANS 10400 Part XA Building Regulations On average for the six climatic zones the SANS 204 compliant LSF specified to SANS 517 consumes 162.3% more heating and cooling energy than the SANS 204 compliant with its higher wall R-value (R0.60) to that Insulated Cavity Brick walled 40m² house. ofLooking at the different climatic zones LSF specified to SANS 517, compared to the 280mm 220mm Solid Double Brick (R0.45), is Insulated Cavity Brick house, used: generally (26.6%) more energy efficient than LSF specified to SANS 517 across the six Climatic Zones.

SUPERIOR THERMAL PERFORMANCE

• 56650.0% more energy in Climatic Zone 3 • 298.2% more energy in Climatic Zone 4

• 179.4% more energy in Climatic Zone 5 Table 4 – Gross annual heating and • 65.1 % more energy in Climatic Zone 6 cooling energy for 130 mhouse in each 4.3 Gross annual heating and cooling energy of a 130 m² house: climate zone expressed in kWh Table 4 - Gross annual heating and cooling energy for 130 m² house in each climate zone expressed in kWh

Climatic Zone

Wall Types

LSF specified to SANS 517, compared to the 270mm Cavity Brick house, used: • 6.7% less energy in Climatic Zone 1 • 49.2% more energy in Climatic Zone 2 • 27.9% more energy in Climatic Zone 3

1

220mm Solid Clay Brick

01

02

03

04

05

06

Bloemfontein

Pretoria

Musina

Cape Town

Durban

Upington

4405

2797

787

2242

909

4762

3251

2023

78

1618

619

3682

1855

1164

45

872

322

2228

2650

2492

1199

2104

1358

3908

270mm Cavity 2

(50mm) Clay Brick with NO insulation 280mm Cavity

3

(50mm) Clay Brick with insulation

4

Light Steel Frame to SANS 517

Tabulating the gross heating and cooling energy consumed by a 130 m² house for the six climatic zones shown in Table 4 above, SANS 10400 Part XA compliant 220mm Solid Double Brick (R0.45), compared to LSF specified to SANS 517, uses: • • • •

66.2% more energy in Climatic Zone 1 THE GREEN BUILDING 12.2 % more energy in Climatic Zone 2 34.4% less energy in Climatic Zone 3, 6.5% more energy in Climatic Zone 4

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Tabulating the gross heating and cooling energy consumed by a 130 m2house for the six climatic zones shown in Table 4 above, SANS 10400 Part XA compliant 220mm Solid Double Brick (R0.45), compared to LSF specified to SANS 517, uses: • 66.2% more energy in Climatic Zone 1 • 12.2 % more energy in Climatic Zone 2 • 34.4% less energy in Climatic Zone 3, • 6.5% more energy in Climatic Zone 4 • 33.1% less energy in Climatic Zone 5 • 21.8% more energy in Climatic Zone 6. In the case of the SANS 10400 Part XA compliant 130 m2 Cavity Brick (R0.60) walled house however, energy efficiency is on average 21.6% superior to LSF specified to SANS 517 for the six climatic zones. Looking at the different climatic zones, LSF specified to SANS 517 compared to the 270mm Cavity Brick house, uses: • 18.5% less energy in Climatic Zone 1. • 23.2% more energy in Climatic Zone 2, • 1437.2% more energy in Climatic Zone 3, • 30.0% more energy in Climatic Zone 4, • 119.4% more energy in Climatic Zone 5, • 6.2% more energy in Climatic Zone 6. As with the 220mm Solid Double Brick house, the lower energy usage of the SANS 204 compliant LSF 130 m2house specified to SANS 517 in Climatic Zone 1 is more than reversed when insulation R1.0 is added in the cavity to provide a wall CR Product in compliance with SANS 204 Energy Efficiency Standards for masonry buildings. As shown the 130 m² Insulated Cavity Brick house presented 42.9% more energy efficient than the LSF house specified to SANS 517 (R2.2) in Climatic Zone 1. With insulation applied in the cavity of the 130 m² brick walled house in compliance with SANS 204 Energy Efficiency Standards for masonry building, thermal efficiencies in all six climatic zones is ‘optimised’ affording a 52.8% average lower energy usage than the 130 m² LSF house specified to SANS 517.

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Looking at the performance in the different climatic zones, LSF specified to SANS 517 compared to 280mm Insulated Cavity Brick, uses: • 42.9% more energy in Climatic Zone 1. • 114.1% more energy in Climatic Zone 2, • 2564.4% more energy in Climatic Zone 3, • 141.3% more energy in Climatic Zone 4, • 327.7% more energy in Climatic Zone 5, • 75.4% more energy in Climatic Zone 6. With the higher wall R-value LSF specified SANS 517 house using between 42.9% (Climatic Zone 1) and 2564.4% (Climatic Zone 3) more energy than the lower R-value SANS 204 compliant Insulated Cavity Brick walled house across the six climatic zones, logical deduction points to best pay back for insulation applied being the preserve of clay brick wall construction. This was confirmed in studies 6 & 7. 5. Summation: The findings show that when it comes to advancing energy efficiency through the application of SANS 10400 Part XA ‘Deemed to Satisfy’ Building Regulations and SANS 204 Energy Efficiency in Buildings Standards (prescriptive and voluntary), conventional clay brick wall constructions, 220mm Solid Double Brick and 270mm Cavity Brick supplemented where appropriate with insulation, provide all the necessary options for achieving optimal energy efficiency outcomes in both day-time occupancy (12 hours) and all-day occupancy (24 hour) buildings. 220mm Solid Double Brick wall construction, by virtue of its propensity to absorb a large quantity of heat energy for a small rise in temperature and thermal lag of 6 hours, presents as the pre-eminent walling system for day-time (12 hour) occupancy office/ institutional type buildings with un-insulated 270mm Cavity Brick the ‘bench mark’ for advancing the energy efficiency requirements of all-day (24 hour) occupancy residential buildings. Supplementing the inherent thermal mass and resistance provided by SANS 10400 Part XA compliant conventional brick wall


11 constructions with additional insulation between the brick skins to provide wall CR Products in compliance with SANS 204 Energy Efficiency Standards for masonry buildings, provides all-day occupancy buildings with the most capable wall construction for dealing with the thermal comfort challenges presented by dynamic external environments in South Africa’s six major climatic zones. The maximized energy efficiencies provided by Insulated Cavity Brick present

SUPERIOR THERMAL PERFORMANCE

as the ‘superior’ benchmark for SANS 204 compliant Insulated Lightweight wall construction systems to aspire. It does so with best payback for the insulation applied. The research findings highlight that Light Steel Frame Building (LSFB) specified to SANS 517 in compliance with SANS 204 Energy Efficiency Standards generally presents a thermal efficiency compromise when applied in the three building typologies and occupancies modelled.

References

• Vosloo P., Harris H., Holm D., van Rooyen N., Rice G., (April 2015), A Thermal Performance Comparison Between Six Wall Construction Methods Frequently Used in South Africa, Department of Architecture, University of Pretoria • Page A.W., Moghtaderi B; Sugo H. O; Hands S; (2009), A Study of the Influence of the Wall R-value on the Thermal Characteristics of Australian Housing, University of Newcastle, Australia • Page A.W; Moghtaderi B., Alterman D., Hands S., (2012), A Study of the Thermal Performance of Australian Housing, Priority Research Centre for Energy, Priority Research Centre for Energy, The University of Newcastle, Australia, www.thinkbrick.com.au • Energy Efficiency and the Environment – The case for Clay Brick – Edition 4, www.thinkbrick.com.au • Braune M., Gray W., Oxtoby S., (2009/2010), 40m² Low Cost Housing Energy Modelling Project, WSP Green by Design • Harris H., (2009), Thermal Modelling of a 132m² CSIR house using Visual DOE software, Structatherm Projects • Braune M., (2010), External Wall Types Assessment for 130m² Residence, WSP Green by Design • Energetics (Pty) Ltd (February 2010), LCA of Brick Products, Life Cycle Assessment Report, Final Report after Critical Review, for Think Brick Australia – http//www.thinkbrick.com.au • Johannsen A., (2012), A Parametric Energy Modelling of Middle Income 130m2 Residences for South African Conditions in Six Climatic Regions in South Africa, with Four Walling Systems • Johannsen A., (26 February 2013), A Review of Computer-based Calculation Methods for Simulating Unsteady-state Heat Transfer through Walling Systems • Lin J., (October 29, 2007) Tutorial – Introduction to Ecotect™ V5.6 modelling software, Cal Poly Panoma Department of Architecture (www.toolsforsustainability.com) • Rees S.J., Davies M.G., Spitler J.D., Haves P., (January 2000), Qualitative Comparison of North American and U.K Cooling Load Calculation Methods published in HVAC & R Research Volume 6, No 1

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‘PROVIDING WORKMANS’ COMPENSATION TO THE BUILDING AND CONSTRUCTION INDUSTRY SINCE 1936’


Overview of Floor Coverings Ceramic tile, concrete, cement Additives & Carpet

Zonke Dumani & Naalamkai Ampofo-Anti


12 Ceramic Tiles Ceramic tile is one of the most widely used materials in construction. Ceramic tile has been the preferred choice around the world for centuries due to the abundant natural materials used to make it. Ceramic tiles are generally used in interior, exterior, commercial, institutional and residential applications for floor coverings. Ceramic materials may constitute about 50% of all materials in a building (Pini et al., 2014). Ceramic tiles are made of mineral-based natural materials including clay, sand, feldspar and other natural substances. These raw materials after suitable preparation are either pressed or extruded into the desired shape. Glaze is applied, as well as decorative treatment and fired at high temperatures in a kiln. Benefits and features of ceramic tiles Ceramic tiles are durable and last a life time when compared to other flooring covering materials. The ceramic tile is expected to last at least as long as the building itself if properly installed and maintained. Ceramic tiles are very hygienic and extremely easy to maintain. Simple water-based cleaning materials are all that is required for maintenance. Ceramic tile does not release volatile organic compounds (VOCs) into the air since the tile is fired at high temperature. Therefore the tiles offer significant advantages for indoor air quality. Ceramic tile has been proven to survive fire and floods, can be installed over existing tile and salvaged or disposed of easily. Life cycle environmental impacts of a ceramic tile The entire life cycle of a ceramic tile consists of five stages including raw material extraction and processing, manufacturing of the tiles, installation, use of the tiles and maintenance, end of life (reuse, recycling and landfill). In order to establish the environmental impact of ceramic tiles, the entire life cycle must be analysed.

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Raw material acquisition and manufacturing The most significant environment aspects associated with the production of ceramic tiles are the following (Edirisinghe, 2013): gas emissions, water consumption and disposal of waste water, energy consumption and solid waste. Gas emissions The production of ceramic tile results in the release of gas emissions to the environment. These gas emissions include particulate matter (PM), nitrogen oxides (NOx), sulfur oxides (SOx), carbon monoxide, carbon dioxide, fluorine compounds, lead compounds. The gaseous emissions released during the production of ceramic tiles from the firing and drying processes are mainly derived from the ceramic raw materials and fuel used. Fuel combustion at the kilns and some dryers results in emissions of CO2, CO, SOx, NOx. These gaseous emissions cause global warming, eutrophication and other environmental impacts. Fluorine emissions produced during the firing are a result of the fluorine compounds that are present in clay. The processing of clay leads to dust formation. The fine particulates if not adequate control pose health problem to human as it can cause silicosis. The lead-based glazing was used in the ceramic industries, however it was eliminated and replaced with boron because it can cause carcinogen. However, the use of boron-based glazing results in substantial atmospheric releases of arsenic (Ampofo-Anti, 2015). Water consumption and disposal of waste water In the manufacture of ceramic tiles water is mainly used in the preparation of mixes and glazes and to wash production lines. Part of the water evaporates during the drying and firing process, while the rest constitutes the waste water (Edirisinghe, 2013). As a result, the contaminated water THE GREEN BUILDING HANDBOOK

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cannot be discharged in to the environment without severe treatment. Energy consumption The production of ceramic tile is a highly energy intensive process. The primary energy consumption in the production of ceramic tile is for kiln firing, followed by the drying process. Solid waste Most wastes generated by ceramic tile production arise from the damaged tiles. Other waste in the production tiles are exhaust oils, paper, wooden pallets, plastic, metal scrap etc. (Edirisinghe, 2013). Transport Although environmental impact from the transportation of ceramic tiles is relative small compared to other impacts across other life cycle stages such as material acquisition and manufacturing it must still be considered. Environmental impacts associated to transportation arise from the use of fuel and subsequent release of greenhouse gas emissions that contribute to global warming. In order to help minimize these impacts, raw materials used to make ceramic tiles must be sourced locally. Installation Typically, ceramic tiles are laid on mortar and the spaces between the tiles are filled with grout. The chemicals for mortars and grouts contribute to volatile organic compounds (VOCs) and can affect the indoor air quality. LEED has set requirements VOC content of adhesives, grout and sealers to be used when making tiles. Furthermore, mortar and grout are cement-based products and cement production is a very intensive process. Cement production is one of the largest contributors to global warming (Humphreys and Mahasenan, 2002). Cement additives such as fly-ash, blast furnace slag and silica fume should be used to produce mortar and grout. Use-stage and maintenance The service life of ceramic tile is unique in that itâ&#x20AC;&#x2122;s not dependant on the amount of floor traffic

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and the type and frequency of maintenance. The ceramic tiles is expected to have lifespan the same as that of the service of the building in which they are used. Ceramic tile offers ease of maintenance with simple, water-based cleaning materials. The low maintenance of tile helps to save on consumption of resources and energy. Furthermore less money needs to be spent on different cleaning products to keep tiles new. End of life Ceramic tiles are inert by nature and can be disposed of in the environment without particular hazards. The ceramic tiles can be landfilled, reuse or recycled. The ceramic tiles can be recycled without any special treatments in multiple applications including to create road substrates, inert fillers. Actions for environmental impact improvement The ceramic tile production was identified as the dominant phase towards the environmental impacts in the ceramic tile life cycle. Therefore, actions that can be taken to reduce the environmental impact of ceramic tiles are listed below. Reduction of gas emissions According to Timellini et al. 2005, the gas emissions can be reduced by over 90% through the use of appropriate waste treatment technologies. In addition, minimisation of the gas compounds in raw materials and the use of emission limit from standards such as GECA hard flooring standards should be used to reduce gas emissions. Reduction water consumption and disposal of waste water It is possible to reuse the wastewater in the production process and as a result minimizing the consumption of fresh water and eliminating the disposal of wastewater (Timellini et al., 2005). Reduction of energy consumption Alternative fuels such as renewable fuels should be used instead of fossil fuels to help reduce


12 the impact of energy use. Furthermore, energy consumption is mainly related to the use of kilns for the drying and firing of ceramic tiles, therefore improvement of design of kilns and dryers should be implemented. Additionally, the heat generated in the production process should be recovered and used in the process. Carpets Carpet has been in use worldwide for thousand years. Carpet, after ceramic tile, is the most used floor covering in South Africa (CIDB, 2007; Mebrathu and Jaber, 2012). Carpet is very soft, slip-resistant and quite beautiful. Carpet can be made from synthetic fibres or natural fibres. Carpet comprised of a pile fibre on a primary backing which is attached with a binder to a secondary backing (AmpofoAnti, 2015). Carpet is suitable for both commercial and residential applications. Technical system of carpet Carpet is usually made from synthetic fibres or natural fibres. Synthetic carpet fibres include nylon, polypropylene and polyester all of which are petroleumbased either from crude oil or natural gas (Ampofo-Anti, 2015). Nylon is the most commonly used synthetic fibre for carpets, mainly because of its durability and can be used for areas of high traffic (Green seal, 2001). Natural fibres include animal fibres and plant fibres. Wool is the natural fibre most commonly used in the production of carpets. However, carpet made with wool fibre is not as durable as nylon carpet and usually wool fibre is combined with small amounts of nylon fibre to provide wear resistance. Most carpet fibres are dyed and most protected with a factor y applied stain repellent (Ampofo-Anti, 2015). After, the pile fibre is tufted or woven into the primary backing which in turn is bonded to a secondary backing. The secondary backing provides strength and

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Reduction of solid waste The solid waste should be recycled back to the production process and as a result minimizing the raw materials used. However, it is not always possible to reuse all the waste materials within the production process itself (Timellini et al., 2005). stability to the carpet (Green seal, 2001). Polypropylene is predominantly used as the backing material for carpet; however some other materials such as polyvinyl (PVC), polyurethane and jute may be used. Jute is a renewable bio-based product however is not as durable as the synthetic back ings (USEPA, 2001). The binder usually used for attaching primary and secondary backings is styrene butadiene rubber (SBR) synthetic latex (Green seal, 2001). The backing can contribute up to 60% of the carpet material by weight (Green seal, 2001). Life cycle environmental impacts of carpet Environmental and health concerns a s s o c i a te d w i t h c a r p e t c a n o c c u r throughout the entire life cycle of carpet. It is vital to identify the environmental and health hotspots in the life cycle of carpet and actions that can be taken to improve the environmental and health problems. The life c ycle assessment consider the impacts from raw material e x t r a c t i o n a n d p ro c e s s i n g, c a r p e t manufacturing, transpor t, installation, use and maintenance of carpet, end of life (reuse, recycling and landfill). Raw material acquisition and manufacturing The production of carpet is a very energy and water intensive process and produce harmful air emissions. Additionally, toxic materials are used and released in the production of carpet and can have serious effects on human health. THE GREEN BUILDING HANDBOOK

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The major it y of the environmental impacts are generated prior to carpet making. Synthetic fibres are petroleum based and for that reason contribute to the environmental burden associated with exploration and refining of fossil fuels. Although wool is a renewable source and requires less energy than synthetics, wool-washing process consumes huge amounts of water (Green seal, 2001). As a result, wastewater and solid wastes are generated. Carpet fibre dyeing is highly energyintensive and consumes a lot of water generating wastewater. Almost all the synthetic backing materials used in carpet have toxic issues. Transport The environmental impacts associated with transportation need to be considered. Long shipping distances requires large amounts of energy and generates greenhouse gas emissions that contribute to global warming. Therefore, raw materials for carpet production must be locally sourced to cut transport impacts. Installation Adhesives are used for installing carpet. Styrene butadiene rubber (SBR) latex as an adhesive compound is commonly used to install the carpet. The production of SBR involves toxic chemicals, for example by-product 4-phenylcyclohexene has a very low odor threshold and affects the indoor air quality. Other toxic chemicals emitted from carpet include styrene, formaldehyde, and all can present major health concerns. According to the Good Environmental Choice Australia (GECA) carpets standard, water-based that contain no more than 5% VOC by weight adhesives should be used for the installation of carpets. Use-stage and maintenance Carpet is less durable compared to other floor coverings such as ceramic tile, concrete tiles, marble tile, and vinyl tile. Maintenance is very vital to enhance the performance and appearance of carpet. Regular vacuum cleaning is necessary to remove dust, dirt and other contaminants for better indoor air quality and to preserve the life of carpet. Furthermore, quick removal of spills is

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essential to avoid stains and fungal growth. Carpet, unlike other floor coverings, requires relatively frequent replacement (about every 6 years). Energy consumption for vacuum cleaning is the largest contributor of the impacts caused during the use phase. End-of-life Although carpet has a short life span, it does not readily degrade and will last forever in a landfill. Carpet in landfill can cause emission of methane that contributes to global warming. Carpet can be incinerated for energy recovery because of the petroleum-based content in materials used to produce carpet. However, polyvinyl chloride, commonly used for carpet backing, can release dioxins, compounds that are potent carcinogens. Recycling of carpet is the best option; however it is very difficult to separate the materials, typically at least three different materials are bonded together. It is very difficult to recycle carpet but not impossible and considerable energy might be required. Actions for environmental improvement The raw material acquisition and carpet manufacturing and use and maintenance stages are the dominant phases towards the environmental impacts in the carpet life cycle. Therefore, these are the life cycle stages where attention could be efficiently focused on improvements in the environmental performance of carpet. As mentioned previously carpet materials release VOCs that affect air quality. The Carpet and Rug Institute recommends VOC limits for carpets, cushion and adhesives and this has been endorsed by Green Seal as indicated in Table 1. Table 1: Maximum allowable factors for finished carpet, adhesives, and cushion (Green seal, 2001). In order to reduce water consumption from carpet dyeing, GECA carpets standard recommend the use of solution dyeing. Solution dyeing does not involve any aqueous dye solutions or drying steps (Green seal, 2001). Another potential area for improvement is the end-of-life. In closed-loop recycling, carpet materials are recycled through mechanical and


12 thermal processes without changing the chemical form of materials (Green seal, 2001). Nylon 6 can be recycled using the closed-loop cycling by mechanical separation from the backing. If re-use or closed-loop recycling of carpets is not possible, then the alternative is downcycling

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of the carpet materials. However, closed-loop recycling of carpet is preferable to downcycling because carpet is usually treated as one material and material produced is of a lesser value.

Carpet (mg/m2hr)

Pollutant

≤0.05

m2hr)

< 0.05 ≤ 0.3 ≤ 0.05

BHT (Butylated hydroxytoluene) Formaldehyde Styrene Total Volatile Organic Compounds

Cushion (mg/

≤3.0

2-Ethyl-1-Hexanol 4-PC(4-Phenylcyclohexene)

Adhesive (mg/m2hr)

≤ 0.4

≤ 0.5

≤10.0

≤1.0

Table 1: Maximum allowable factors for finished carpet, adhesives, and cushion (Green seal, 2001).

Concrete Tiles Concrete tiles have a long history that dates back in the 1850s. Concrete tile are individually handmade colourful tiles by skilled artisans. Concrete tiles are available in patterns and numerous colours and can be customized to suit individual design needs. The combination of beauty, durability, versatility and low maintenance has led to the re-emerge in the use of concrete tiles. Concrete tiles are suitable for commercial and residential applications on both walls and floors. They can be used either indoors or outdoors. As concrete tiles are handmade, it is important to expect slight imperfections,

Layer

appearance of fine cracks, and irregular edges, which give them character and depth. Technical system of concrete tile Concrete tile is made from a mixture of cement, sand, natural pigment and marble powder. Unlike ceramic tile, concrete tile does not use clay, glazes or kilns but have their own ingredients and processes. The concrete tile is made up of 3 individual layers (see Table 1) that come together to form a very solid, dense hard tile. Table 1: Basic constituents of concrete tiles The pigment layer is poured into a handmade metal mold, backed with 2 layers of concrete and then hydraulically pressed under high

Constituent material White Portland cement, white powdered marble, natural

1

pigments

2

Fine sand, Ordinary Portland cement (OPC)

3

Solid concrete

Function Provide wear resistance, colour and brightness Provide compression reinforcement for heavy traffic Made to be strong and porous for impact strength before and after installation

Table 1: Basic constituents of concrete tiles

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pressure until the layers become a single tile. Then, the tile undergoes air curing to allow the cement mixtures to harden and strengthen. The handmade concrete tiles can be made into nearly any design, size and shape. Each of these ingredients can have environmental impact during the life cycle of the concrete tiles. Life cycle environmental impacts of concrete tile The environmental sustainability of concrete tiles is of importance. Life cycle assessment is an effective tool to evaluate the environmental impacts associated with concrete tiles. By identifying the environmental hotspots in the life cycle of concrete tiles, actions can be taken to improve the environmental problems. The entire life cycle of a concrete tiles includes raw material extraction and processing, manufacturing of the tiles, transport, installation, use of the tiles and maintenance, end of life (reuse, recycling and landfill). Raw material acquisition and manufacturing Concrete tiles are handmade with ingredients made from natural pigments and materials. In addition, when producing concrete tiles no firing process is required and no glaze is applied on the tile. So, no energy consumed or gaseous emissions released for kiln firing. However, concrete tile is a cement-based product and the production of cement is a very energy intensive process. Additionally, the production of cement is one of the major contributors to global warming (Humphreys and Mahasenan, 2002). As a result, the production of cement is the environmental hotspot in the production of concrete tiles. Transport It is always better to acquire local raw materials to reduce energy consumption and emissions of long distance shipping. Therefore, all the constituents to make concrete tile should be regionally sourced. Transportation of concrete tiles for distribution results in high environmental

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impact because the tiles are heavier than ceramic tiles. Installation The installation of concrete tiles requires mortars, grouts and penetrating sealers. Concrete tiles are laid on mortar and grout is applied to fill the spaces between tiles. Penetrating sealers protect concrete tiles from stains and wear. The chemicals for mortars, grouts and sealers can significantly influence the environmental and human health profiles of the ceramic tiles. The chemicals used may adversely affect the indoor air quality if volatile organic compounds (VOCs) released are high. Therefore, chemical used should contain low VOCs. LEED has set requirements VOC content of mortar, grout and sealer to be used when making tiles (Deutsche Steinzeug, 2013). Use-stage and maintenance Concrete tile is durable, very tough and has a high lifespan as compared to other floor coverings such as carpet, vinyl tile and wood laminates if properly installed. Unlike ceramic tiles, maintenance of concrete tiles largely depends on the amount of floor traffic. Concrete tile should be regularly cleaned with a neutral cleaner. If necessary, tiles can be buffed with a white pad (CTMA). Concrete tiles are porous and need to be periodically sealed to protect from staining and wear. End-of-life Concrete tile are made from natural ingredients and can be recycled. Concrete tile can be crushed and recycled as aggregate for sidewalks and roads. Actions for environmental improvement The production of cement was identified as the environmental hotspot in the production of concrete tiles. For that reason, action has to be taken to reduce the environmental impact of cement production. Cement additives such as fly-ash, blast furnace slag and silica fume should be used to partially replace OPC in order to reduce the environmental impact of cement production. The partial replacement of


12 OPC with cement additives results in less energy use, less greenhouse gas emissions and reduced raw materials consumption and thereby also reducing the production costs of concrete tiles. Furthermore, the use Marble Tiles Marble is a metamorphic rock that is formed by crystallizing limestone or dolomite rock at high temperature or pressure (Genuine Stone, 2008). Marble is found in the mountainous regions of most countries. Marble has been used as a flooring material all over the world (Center for Clean Products, 2009a). The combination of durability and recyclability make it a sustainable flooring choice. Marble tile productive life cycle The productive life cycle of marble is constituted by the following phases (Nicoletti et al., 2002): quarry processing and marble processing which includes raw blocks cutting, cutting of the standard size blocks and polishing, buffing. Quarry processing Marble is extracted from the quarries using different techniques depending on the characteristics of the rocks and deposits (Nicoletti et al., 2002; Traverso et al., 2010). The main technique utilises diamond wire and diamond saw cutting machines (Traverso et al., 2010). The diamond wire, which is used in conjunction with water and sand suspension that is poured into the channels, makes a linear cut in the rocks (Nicoletti et al., 2002; Traverso et al., 2010). The sand improves the abrasive function while water cools the diamond wire (Nicoletti et al., 2002). The blocks are removed from the rock face using explosives. After the rocks have been cut and removed from the mountains, the quarry operations end with sectioning and cutting of the blocks. Marble processing The marble blocks are moved from the mine to the factories. In the factories the blocks are classified, sorted and cut. Using the gang

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of recycled materials such as crushed glass, recycled aggregates in the production of concrete tiles should reduce raw materials consumption. saw, the marble blocks are cut into sheets of required thickness and further cut into required sizes (Tikul, 2011). The polishing and buffing operations can be done in factories but sometimes they take place after the laying (Nicoletti et al., 2002). Life cycle environmental impacts of marble tile Environmental impacts associated with the entire life cycle of marble tile should be evaluated in order to identify the hotspots. By identifying the hotspots, actions can be taken to improve the environmental performance of the marble tile. The life cycle of a marble tile includes raw material extraction and processing, manufacturing, transport, installation, use and maintenance, end-of-life (reuse, recycling and landfill). Raw material acquisition and manufacturing Environment impacts associated to marble tile production arise particularly from the extraction and cutting steps. The marble quarrying is an energy intensive process due to the use of electric energy and fuels to operate the equipment. Explosives were used to extract marble blocks from the mountains. Although the energy utilised for explosives is very small in comparison to the energy consumed to operate the equipment, its use produces the quarry scraps, the so called ‘spoil’. Most wastes generated by marble tile production arise during quarrying operations. These include the ‘spoils’ and other scraps that consist of small pieces of marble and dust (Traverso et al., 2010). Water is used in extraction mainly to keep machines (diamond wire and saws) cool.

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The cutting of the marble block to transform into the tile is an energy intensive process in the entire production of marble tile (Liguori et al., 2008). Mostly the energy is used to operate the cutting machine. Water used to keep cutting machines (gang saw) cool and polishing wheels produces a large amount of sludge. The water is usually recycled by a flocculating process. The generated solid waste in this process consists of sawing sludge and stony fragments (Traverso et al., 2010). After cutting treatments, marble products usually show some cracks and holes that are filled in with resin (Traverso et al., 2010). The resin is used to improve the resistance of tiles before the finishing treatment takes place (Liguori et al., 2008). The use of this material can be harmful to the environment and health and thus limiting the consumption is important. The production of marble tile results in the release of air emissions to the environment. These air emissions include particulate matter (PM), nitrogen oxides (NOx), sulfur oxides (SOx), carbon monoxide and carbon dioxide. The greenhouse gas emissions (NOx, SOx, CO2, CO) arise from explosives, fuels and electricity. These emissions contribute to global warming, eutrophication and other environmental impacts. Quarry operations generate a significant amount of dust. The fine particulates if not controlled is known to cause silicosis. Transport Another life cycle stage that needs consideration is transportation and the associated environmental impacts arise from the use of fuel. Transportation stage in the production of marble tile is highly complex and needs to be well considered and planned. Marble block is very heavy and transportation can become expensive and cause environmental problems. Since quarries must be located where the geologic deposit has formed, the decision

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that needs to be made is the location of the processing plant, whether it is at the same site as the quarry or miles apart (Center for Clean Products, 2009b). Nevertheless, the location of consumers is also critical. Therefore, well-planned transportation needs to be implemented to minimize the negative environmental impacts and reduce costs. Installation The installation of marble tiles requires mortars, grouts and sealers. Marble tiles are laid on mortar. Marble tiles are soft, porous and absorb moisture. Additionally, marble tiles are prone to cracking and chipping. Therefore, pre-sealing the tiles prior to grouting is recommended. Grout is then applied to fill the spaces between tiles. After the grout has properly cured it is recommended to seal the tiles again. Mortars, grouts and sealers applied when installing the marble tiles may emit the volatile organic compounds (VOCs) and affect the air quality. LEED has set requirements VOC content of adhesives, grout and sealers as followed: tile adhesive < 65 g/l, grout < 50g/l and sealers < 100 g/l (Deutsche Steinzeug, 2013). Use-stage and maintenance Marble tile is durable and will last a lifetime if properly maintenance. Regular vacuuming or sweeping is necessary to remove dirt and dust that will scratch the surface of the tile. The marble tile should be cleaned with neutral cleaners because acidic cleaners like vinegar and strong alkaline cleaners can scratch, dull and eventually damage the tile. Proper maintenance of marble tile will substantially delay the need for polishing and buffing. However, if the marble tile has become dull, stained and scratched then to restore the surface shine the use of marble polish may be applied. End-of-life The marble tile can be landfilled, reuse or recycled without particular hazards.


12 The marble tile are inert by nature can be recycled in numerous applications such as landscaping, retaining walls, filler. Actions for environmental improvement The environmental hot spots in the production of marble tile were identified to be the amount of scraps produced during the extraction process and the high electricity consumption. Therefore, actions have to be taken to reduce the environmental problems. It is impossible to eliminate the scraps produced during quarry operations. However, techniques need to be implemented to reduce the scraps generated during the operations. The use of explosives produces the scraps and it is not

FLOOR COVERINGS

possible to control the explosion very well. For that reason, explosives should be substituted with another technique in order to achieve more control in the moving of marble blocks from the mountain. The electric energy was used for the functioning of the machine in the production of marble tile. Therefore the electric energy can be reduced by improving the efficiency of the technology in the production system. In order to reduce the air emissions and water emissions, the European Ecolabel (EU Ecolabel, 2009) and the Good Environmental Choice Australia (GECA, 2008) standard for hard floor covering criteria should be carried out. The sludge discharged to the environment must not exceed the following limits

Emission

Limit (mg/L)

Cadmium

0.015

Chromium (VI)

0.15

Iron

1.5

Lead

0.15

Air emissions are released to the environment in the production of marble tile. Emissions to air must not exceed the following limits

Emission

Limit (mg/L)

Dust

300

SO2

850

NOx

1200

Styrene*

2000

*The limit value for styrene include the production of any synthetic resin that may be used

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References

Ceramic • Ampofo-Anti, NL., 2015. A brief introduction to chemical hazards in the life cycle of building products with floor covering as a case study. Pretoria: CSIR • Edirisinghe, J., 2013. Life cycle assessment of a ceramic tile produced in Sri Lanka. ARPN Journal of Science and Technology 3 (11), 1060-1070 • Humphreys, K., and Mahasenan, M., 2002. Toward a Sustainable Cement Industry – Substudy 8: Climate Change. Battelle – World Business Council for Sustainable Development • Pini, M., Ferrari, A.M., Gamberini, R., Neri, P., and Rimini, B., 2014. Life cycle assessment of a large, thin ceramic tile with advantageous technological properties. International Journal of Life Cycle Assessment 19, 1567-1580 • Timellini, G., Palmonari, C., and Fregni, A., 2005. Ceramic floor and wall tile: An Ecological building material, Tiletoday 13(46), 18-26 Carpet • Ampofo-Anti, NL., 2015. A brief introduction to chemical hazards in the life cycle of building products with floor covering as a case study. Pretoria: CSIR • CIDB, 2007. The building and construction materials sector, challenges and opportunities. Pretoria: Construction Industry development Board • Green seal, 2001. Choose green report – carpet. [Online] available from https://www.wbdg.org/ccb/ GREEN/REPORTS/cgrcarpet.pdf, [accessed: 22 September 2016) • Jaber, R., and Mebrathu, B., 2012. Commercial flooring market in South Africa. Bachelor Thesis in Business Administration, Malardalen University, Sweden • Mahalle, L., 2011. A comparative life cycle assessment of Canadian hardwood flooring with alternative flooring types. FPInnovations, Vancouver. [Online] available from: http://hardwoodinitiative.fpinnovations.ca/files/publications-reports/reports/project-no1-flooring-comparison-lca-final-report.pdf, [accessed: 22 September 2016] • USEPA, 2001. Greening your purchase of carpet. United States Environmental Protection Agency Concrete Tile • CTMA (Concrete Tile Manufacturers Association), CTMA handbook for concrete tiles. [Online] available from: http://www.stepstoneinc.com/docs/ctma_handbook.pdf, [accessed: 27 September 2016] • Humphreys, K., and Mahasenan, M., 2002. Toward a Sustainable Cement Industry – Substudy 8: Climate Change. Battelle – World Business Council for Sustainable Development • Deutsche Steinzeug, 2013, Green Building with ceramic tiles - Product information for LEED APs. [Online] available from: https://www.sentinel-bauverzeichnis.eu/adbimage/4397/asset-original/information_for_ leed_11_13.pdf, [accessed: 22 September 2016] Marble Tile • Center for Clean Products, 2009a.Case study: Durability of stone flooring in high traffic areas. Natural Stone Council

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12

FLOOR COVERINGS

• Center for Clean Products, 2009b. Best practices of the Natural Stone Industry – Transportation. Natural Stone Council • Deutsche Steinzeug, 2013, Green Building with ceramic tiles - Product information for LEED APs. [Online] available from: https://www.sentinel-bauverzeichnis.eu/adbimage/4397/asset-original/ information_for_leed_11_13.pdf, [accessed: 22 September 2016] • Genuine Stone, 2008. Material fact sheet marble. Natural Stone Council • Liguori, V., Rizzo., G., and Traverso, M., 2008. Marble quarrying: an energy and waste intensive activity in the production of building materials. WIT Transactions on Ecology and the Environment 108, 197-207 • Nicoletti, G.M., Notarnicola, B., and Tassielli, G., 2002. Comparative life cycle assessment of flooring materials: ceramic versus marble tiles. Journal of Cleaner Production 10, 283-296 • Tikul, N., 2011. Environmental performance of marble tile life cycle. Faculty of Architecture and Environmental Design, Maejo University, Thailand • Traverso, M., Rizzo, G., and Finkbeiner, M., 2010. Environmental performance of building materials: life cycle assessment of a typical Sicilian marble. International Journal of Life Cycle Assessment 15, 104-114

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MATERIALS & TECHNOLOGIES DIRECTORY


The purpose of the following limited directory section is to provide readers with a breakdown of the environmental impacts, considerations, that relate to various construction materials and technologies and to set out some of the innovations being brought through in this regard. The directory features a brief introduction to the category followed by commercial information from related suppliers.

CONTENTS COMPANY

PAGE

STEEL ArcelorMittal South Africa 195 Safintra South Africa 196 PAINT Becker Industrial Coatings 198-199 WATERPROOFING LRSA Industries 201 ARCHITECTURAL GLASS Shaluza Projects 203

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STEEL Steel is an alloy of iron and other elements, primarily carbon, that is widely used in construction and other applications because of its high tensile strength and low cost. Steel's base metal is iron. Steel is one of the most common materials in the world, with more than 1.3 billion tons produced annually. It is a major component in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons. Modern steel is generally identified by various grades defined by assorted standards organizations. Steel is one of the world's most-recycled materials, with a recycling rate of over 60% globally; in the United States alone, over 82,000,000 metric tons (81,000,000 long tons) was recycled in the year 2008, for an overall recycling rate of 83%. Steel production is energy intensive. However, sophisticated energy management systems ensure efficient use and recovery of energy throughout the steelmaking process for reuse, wherever possible. Improvements in energy efficiency have led to reductions of about 60% in energy required to produce a tonne of crude steel since 1960. Modern steel plants operate near the limits of practical thermodynamic efficiency using existing technologies. With most major energy savings already achieved, further large reductions in CO2 emissions are not possible with the available technologies. The targets set out by governments and international bodies require breakthrough technologies via innovation and exploration of new production technologies.

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We are committed to sustainability


Steel Roofing turns Green to Gold G

lobally, the building industry provides 5-10% of employment and generates between 5-10% of its GDP. On the negative side, the built environment accounts for 40 percent of energy consumption, 40 percent of CO2 emissions, 30 percent of the consumption of natural resources, 30 percent of waste generation and 20 percent of water consumption. The challenge for the global construction industry is to meet the world’s growing needs while also limiting the downstream impact of its activities. Steel is becoming increasingly important as a material of choice; it offers a wide range of solutions that make buildings more energy efficient, less costly to construct and occupy, and therefore more sustainable. Steel as an ideal construction material – Steel’s high strength-to-weight ratio reduces a building’s environmental impact and conserves natural resources, requiring less material than traditional construction technologies. Steel roofs allow for easy integration of green technologies – Water harvesting is more hygienic off a smooth surface (such as steel) than off a surface which harbours dust. Steel roofs are also competitive with installation of solar heating panels, and are entirely watertight when junctions are sealed. Steel is the most recycled material in the world – It is 100 percent and indefinitely recyclable, without any quality loss. Recycled steel represents 40 percent of the steel industry ferrous resource in the world. Aside from its green credentials – steel is also fire retardant, and provides high degree of personal safety for occupants

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as it is estimated that 15% of burglaries access the building through a tiled roof. Steel roofing works wonders in low-cost housing – if it incorporated green building elements into low-cost housing developments, affording greater comfort and lower costs to those who can least afford to foot high energy and water bills. Steel can provide more comfortable housing – Aluminium Zinc roofing is highly reflective and is available in cool colours which absorb less heat. Steel also holds less heat over a period of time. Steel roofing is up to 4 percent cooler than clay or fibre cement roof coverings. Government is going green in meeting its national objectives – In partnership with the Council for Scientific and Industrial Research (CSIR), the Department of Public Works (DPW) has developed a Green Building Framework. This Framework will also seek to introduce a green building skills development and training programme, enhance research and development on the subject and establish centres of excellence on green buildings. This is a wonderful and exciting case of working towards ‘A Better Life for all’

www.safintra.co.za Safintra South Africa has seven (7) branches in Johannesburg, Cape Town, Durban, Nelspruit, Port Elizabeth, Polokwane and Bloemfontein and are a proud member of the Safal Group.


PAINT Paint is any liquid, liquefiable, or mastic composition that, after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, color, or provide texture to objects. Paint can be made or purchased in many colorsâ&#x20AC;&#x201D;and in many different types, such as watercolor, synthetic, etc. Paint is typically stored, sold, and applied as a liquid, but most types dry into a solid. The dangers of paint include volatile organic compounds (VOCs) in paint which are considered harmful to the environment and especially for people who work with them on a regular basis. Exposure to VOCs has been related to organic solvent syndrome, although this relation has been somewhat controversial. The controversial solvent 2-butoxyethanol is also used in paint production. In the US, environmental regulations, consumer demand, and advances in technology led to the development of low-VOC and zero-VOC paints and finishes. These new paints are widely available and meet or exceed the old high-VOC products in performance and cost-effectiveness while having significantly less impact on human and environmental health. A polychlorinated biphenyl (PCB) was reported in air samples collected in Chicago, Philadelphia, the Arctic, and several sites around the Great Lakes. PCB is a global pollutant and was measured in the wastewater effluent from paint production. According to one life cycle assessment study it is environmentally advantageous to extend the working life of products by surface-treating them with paint. For solvent-based paint, the solvent, binding agent, pigment and manufacture are responsible for approximately equal proportions of environ- mental loading within the different areas of greenhouse effect, low-level ozone, acidification and eutrophication. For powder paint, the picture is more diffuse - the greenhouse effect is affected most by binding agents. Lowlevel ozone originates mainly in the binding agents and the eutrophication effect is caused almost entirely by filler. The general conclusion form one of the studies is that the greatest part of the environmental impact originates in the actual object which has been painted in most cases, e.g. shelf, kitchen cabinet doors or timber weatherboarding. This applies to most categories for environmental impact. At the same time, the paintâ&#x20AC;&#x2122;s environmental impact cannot be ignored when the environmental impact of a surfacetreated product is analysed. THE GREEN BUILDING HANDBOOK

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PROFILE

B

eckers is an international coatings group with a leading position in its markets worldwide. Sustainability, design and innovation are an integral part of our long history spanning 150 years. At Beckers Group, we recognise our responsibility to incorporate sustainability into all aspects of our business. We support long-term, sustainable development and embrace life-cycle thinking in our strategy, operations and product and service development based on our corporate vision and values. Our Sustainability Committee, selected to represent various business functions at an executive level, is committed to refining our strategy. Compliance is a crucial component of sustainability. We place great emphasis on complying with environmental, health, and safety regulations in all countries in which we do business. To this end, our operations are certified in accordance with industry standards to meet regulation requirements and continuously improve our processes. Beyond fulfilling local laws and regulations, we continuously strive to apply best practices throughout our operations. Our daily activities are governed by Beckers’ Code of Conduct, mandated by Beckers’ Board of Directors and executive management team, which adheres to the ten principles of the United Nations Global Compact. Coil coatings are high-performance liquid paints applied to metal. As the premier supplier of coil coatings globally, the Beckers Group sets trends and industry standards. Coil coatings comprise liquid paint in a wide range of colours and finishes that can be applied to continuous steel or aluminium strip. These can be cured in seconds and recoiled for delivery to end users. The coil coating process not only creates new markets for sheet metal products, but also reduces the environmental impact by minimising

paint waste and making use of excess solvents. Evaporating solvents are incinerated to generate heat for curing ovens, thus preventing waste and pollution. Beckers coil coatings are designed to withstand the toughest indoor and outdoor conditions and possess many qualities required for high-end products. Among others, they are: · Durable · Flexible · Colour-fast · Corrosion and abrasion proof · Scratch and UV light resistant · Thermally reflective · Antibacterial · Self-cleaning From pre-painted solutions for roofing on composite panels for buildings to domestic appliances, Beckers Group offers a complete range of topcoats, primers and backing coats. Working in close cooperation with coil coaters, architects, product designers and engineers across the globe, Beckers Group is recognised as one of the industry’s leading innovators. Many of the company’s product innovations are the result of collaboration with customers, as well as intensive research by expert teams in the Beckers Long Term Development Groups located in the UK and Malaysia. Beckers is working today on solutions for tomorrow. Geared to customers’ needs Beckers performs systematic product testing including accelerated and natural aging tests. All data is reported via specific product integrity software and can be provided on demand. We provide technical assistance along with an in-house coil coating pilot line for logistics services and a full range of customer-specific services. Our teams also conduct training workshops in line with the latest technical developments.

CONTACT DETAILS 105 Houtkop Road, Duncanville, Vereeniging Office +27(0)16 428 4011 Fax +27 (0)86 594 0058 www.beckers-group.com

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WATERPROOFING Joints or gaps that require sealing can be found in many different parts of buildings and civil engineering works. They include joints between elements such as walls and floors; or joints between materials, such as clay brick and steel. The three primary functions of a sealant in any of these circumstances are to fill the joint/gap; form a barrier; and maintain the sealing properties for the expected lifetime within the service environment. To be effective, a sealant must meet other performance requirements in the context of application. For example, joints located within the building envelope need to prevent air, water, dust and wind ingress; and at the same time provide acoustic and thermal insulation as well as fire resistance. The production of primary polymers destined for industrial applications entails inputs of hazardous chemicals and toxic environmental emissions (1). Furthermore, the wide array of additives included in construction sealants formulations may enhance specific performance characteristics such as plasticity, but may also increase the hazardous content of a sealant. Indoor air quality might be severely affected by the presence of joint sealants containing PCB. If a significant amount of these materials are present indoors, and if their PCB concentration exceeds 10 g/kg, rooms where people are present for extended periods should be checked for increased indoor air PCB levels. If the tentative guideline value (22) of 6 Âľg/m3 for PCB in indoor air (on the basis of a daily exposure of 8 h) is exceeded, PCB sources need to be identified, removed, and disposed of as hazardous waste as soon as their PCB content exceeds 0.05 g/kg. In all other cases, the presence of joint sealants containing PCB should be documented so that they may be removed and disposed of when the building is renovated or torn down (2).

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PROFILE

Liquid Rubber provides a wide range of water based, VOC and solvent free products for waterproofing, corrosion and chemical protection or where a protective decorative coating is required. These products cure to provide a seamless, fully adhered flexible membrane which prevents water ingress and resists damage from water, UV, salt, thermal cycling and harmful chemicals. All Liquid Rubber products are both worker and environmentally safe and are available for commercial, industrial and residential markets. Liquid Rubber HighBuild S200 is a single component, liquid applied waterproofing sealant combining high quality bitumen with various polymers that forms a high performance elastomeric waterproof membrane. Containing no solvents, Liquid Rubber Waterproof Sealant™ is non-flammable and the coating will not damage polyurethane or polystyrene insulation materials. A variety of different reinforcing fabrics can be imbedded into the membrane to produce a high strength, superior waterproofing layer. Liquid Rubber A-205 is a brush, roll-on and spray-able high-performance, acrylic, elastomeric coating that can be applied over

many existing surfaces including concrete, wood, brick, metal… which forms a durable, flexible, seamless, colored membrane. Liquid Rubber A-205 contains no solvents, is non-flammable and not affected by sunlight or occasional chemical spills. Liquid Rubber A-205 can be applied on its own or as a topcoat over all Liquid Rubber Products. Liquid Rubber T300 is a brush, spray or roll-on, high-performance acrylic coating that can be applied over many existing surfaces including concrete, wood, brick, metal which forms a durable, textured, seamless, colored membrane. Liquid Rubber T300 is water based containing no solvents, is non-flammable and not affected by sunlight or occasional chemical spills. Liquid Rubber Textured Sealant™ can be applied on its own or as a topcoat over Liquid Rubber Products and offers a cost effective solution for walking surfaces. Contact details: 24 Cecilia street, Paarl Tel. 021 204 7227 email: info@liquidrubber.co.za www.liquidrubber.co.za

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ARCHITECTURAL GLASS Architectural glass is glass that is used as a building material. It is most typically used as transparent glazing material in the building envelope, including windows in the external walls. Glass is also used for internal partitions and as an architectural feature. When used in buildings, glass is often of a safety type, which include reinforced, toughened and laminated glasses. Glass coated with a low-emissivity substance can reflect radiant infrared energy, encouraging radiant heat to remain on the same side of the glass from which it originated, while letting visible light pass. This often results in more efficient windows because radiant heat originating from indoors in winter is reflected back inside, while infrared heat radiation from the sun during summer is reflected away, keeping it cooler inside. Insulated glazing, or double glazing, consists of a window or glazing element of two or more layers of glazing separated by a spacer along the edge and sealed to create a dead air space between the layers. This type of glazing has functions of thermal insulation and noise reduction. When the space is filled with an inert gas it is part of energy conservation sustainable architecture design for low energy buildings. A recent (2001 Pilkington Glass) innovation is so-called self-cleaning glass, aimed at building, automotive and other technical applications. A nanometre-scale coating of titanium dioxide on the outer surface of glass introduces two mechanisms which lead to the self-cleaning property. The first is a photo-catalytic effect, in which ultra-violet rays catalyse the breakdown of organic compounds on the window surface; the second is a hydrophilic effect in which water is attracted to the surface of the glass, forming a thin sheet which washes away the broken-down organic compounds.

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Diverse Urethanes: Diverse Urethanes is involved with the manufacture of a large number of polyurethane systems tailored to meet customer unique requirements. Our products are formulated inhouse and include specialty products such as one component moisture cured polyurea coatings, one component waterproofing coatings and even fire barrier paints and sealants. Diverse Urethanes has a fully equipped manufacturing plant and QC facilities to ensure product conformance and reproducibility. It also has a pool of experienced polyurethane technologists which can meet customer present and future demands. Products are supplied in pack sizes as low as 5kg all the way up to bulk containers.

The company has a BEE certificate and is currently busy with ISO 9001 accreditation We are agents for Era Polyurethane Products who offer a wide range of flooring, waterproofing and

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polyurea spray systems. For more information please go to: www.erapol.com.au Specific products tailored for the construction industry: We manufacture waterproofing systems including Flexiseal L, a UV stable environmentally friendly system that can be mixed with up to 20% concrete and HS 40, a solvent based system, both products are single component, have excellent elongation and can be applied by spray or manually. Both products may be applied to many different surfaces with very little preparation required and are excellent for concrete consolidation. Diverse Urethanes offers a single component bitumen coating which may be used for waterproofing and to refurbish old torch-on. We also have a range of polyurethane flooring systems such as self-levelling and chemically resistant flooring. Our Div Aspartic is a high gloss decorative finish that can be used in areas of high traffic. We offer a wide range of sealants available in a selection of colours. DFS 400 FR has SANS accreditation, SANS 10177 part 9 and our fire barrier paint and sealant has SANS 10177 part 10 accreditation. For further information on our full product range please contact us on info@divure.co.za or 0116082584.


INDEX OF ADVERTISERS

COMPANY

PAGE

AHI Carrier 10 ArcelorMittal South Africa 4-5; 195 Audio Visual Gurus 130-131 Avna Architects and Green Building Consultants 61-63 Barloworld 124 BASF Holdings South Africa 26-27 Becker Industrial Coatings 198-199 Belgotex Floorcoverings 86-89 BlueScope Steel Southern Africa 6-7 Bulkmatech Engineering 18 Cape Brick 140-141 Claybrick Association 173 Council for Scientific and Industrial Research (CSIR) 160 Diverse Urethanes 204 Dulux TRADE / Volcano IMC IFC Envirobuild 72 Fourways Airconditioning 52 Geberit Southern Africa 22 Global Roofing Solutions 119-212 Isofoam 150 Liquid Rubber / LRSA Industries 8; 201 Mapei South Africa 206 Maskam Water 99 Merensky Timber 56 My Sketch / www.Argitek .co.za 24 Nedbank OBC

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INDEX OF ADVERTISERS

COMPANY

PAGE

Oggie Hardwood Flooring 16 Riaan Steyn Architects 43-45 Safintra South Africa 2-3;196 SASSDA 156-157 Shaluza Projects 203 Sika South Africa IBC South African Federation of Hospital Engineering (SAFHE) 160 South African Water Research Commission 90-91 South African Wood Preservers Association (SAWPA) 146 Spunchem International 12 The Federated Employers' Mutual 178-179 Upat SA 80-81 Van Dyck 14 WSP 46-47

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