Integrability of low energy cooling systems in buildings

FACULTY OF ARCHITECTURE MANIPAL UNIVERSITY Dissertation Paper October 2014

Integrability of low energy cooling systems in buildings Niyas Moidu

Abstract

According to the World Bank, the Middle East is one of the largest consumers of energy per capita in the world now and an estimated two-thirds of that in the summer months is used for driving air-conditioning.

The demand for energy consumption for the purpose of air conditioning has been increasing. As the cooling devices are usually electrical powered, the demand for electrical power increases and reaches the capacity limit during the summer time. This study of low energy cooling systems aims at the typologies, functionality and working of cooling systems in large span buildings. With the advent of new solar technologies, low energy cooling systems provide the right answer and satisfy the requirements to make energy efficient buildings. Solar cooling system installations have increased substantially in the last decade and there are a number of installations with successful working records, especially in Europe. Case studies are conducted as an analytical study to see the systems workability in existing situations.

Keywords : Solar cooling,demand,functionality,working,typologies

1. INTRODUCTION 1.1. BACKGROUND By the end of 2011, about 1000 solar cooling systems were estimated to be installed all over the world.

According to the World Bank, the emirates is one of the largest consumers of energy per capita in the world now and an estimated two-thirds of that in the summer months is used for driving air-conditioning. The demand for energy consumption for the purpose of air conditioning has been increasing. As the cooling devices are usually electrical powered, the demand for electrical power increases and reaches the capacity limit during the summer time. But the more innovative way is to use solar energy for driving the air conditioning systems at the location where the temperature is high. A cooling system for building through absorption refrigeration makes direct and efficient use of solar heat, replacing the use of natural gas or electrical energy for vapor compression refrigeration.

2.2 RESEARCH QUESTION -How to efficiently use the concentrating solar collectors for the purpose of air conditioning systems in large span buildings for a better thermal comfort.

2.3 AIM - To study the efficient use of solar collectors for the purpose of air cooling systems in Outdoor spaces for a better thermal comfort.

2.4 OBJECTIVES - The objective of the study is to understand the ideology of a solar cooling system. To study:- the various and techniques for air cooling systems - the different typologies and their limitation - & collect data regarding the above mentioned resources - the feasibility of the air cooling systems in the present buildings - to study any alternate methods to be used during the failure of CSP 2.5 SOPE AND FOCUS OF STUDY Study the performance of the HVAC system, while maintaining comfort conditions in the stadiums/outdoor spaces in low-velocity displacement under-seat supply ventilation.

- Focus on low energy concepts to create thermal comfort -

Apply innovative, green highly efficient cooling technology

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Produce electrical energy by using concentrating collectors

2.6 METHODOLOGY Identifying the various techniques in the working of a Solar concentrating collectors.

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Literature study done through Journals, Articles, & videos regarding parabolic trough particularly single axis transmitting collectors which are mainly used for air conditioning purpose.

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Referring live research articles based on the same topic.

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Contacting companies like Gardener Tao bold and POPULOUS who are responsible for the installations of solar thermal collectors and finding an innovative way to fight the desert heat in Middle Eastern countries for better thermal comfort in stadiums.

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Comparative analysis of various live case studies done.

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Formulation of the final report.

2. LITERATURE REVIEW Why the use of solar thermal energy for air-conditioning in buildings?

There is a large interest from end users according to first observation. Making cold from heat seems to be an interesting technology that appeals to many end users.

Main opinions for solar assisted cooling originate from an energy saving perspective.

- Application of solar assisted cooling saves electricity and thus conventional primary energy sources.

- Solar assisted cooling also leads to a reduction of peak electricity demand, which is a benefit for the electricity network and could lead to additional cost savings of the most expensive peak electricity when applied on a broad scale.

Other arguments originate from a more technical perspective: - Solar energy is almost available at the same time when the cooling is required, this argument holds for both, solar thermal and solar electric based systems.

2.1. DEFINING SOLAR AIR CONDITIONER Solar Air conditioning refers to any cooling system that uses solar energy for the purpose of providing active or passive cooling of a structure or a building. Solar air-conditioning can be done through various methods including solar thermal energy and by use of photovoltaic conversation i.e sunlight to electricity. Solar airconditioning plays an important role in the increasing zero energy and energy plus building designs.

2.2 EMERGENCE & HISTORY OF SOLAR ENERGY

In today’s age of global warming & the gradual reduction of our valuable natural resources, solar energy can be considered as an advantage to our endangered society. Therefore it is important to know what solar technologies are along with its history of origin. Such knowledge is not only beneficial for the sustainability of our future but will also help us to make maximum utilization.

Conflicting to what people may think, solar energy is actually an age old technology. It’s first known use can be traced back to 7th century B.C. The earliest solar power came in the form of glass pieces used to converge sun’s rays for fire. Although the initial use of solar power was mostly in the form of venerating the sun as a god who sustained life, the ancient Greeks and Romans saw the greater potential of the sun. They built their cities and houses in a solar reflexive manner and used glass to trap sunlight for warmth and energy. In the year 1767 a Swiss environmentalist Horace –Benedict de Saussure tried to ascertain the usefulness of sunlight and the heat generated by it by inventing what is now known as a solar collector. He tried to capture the heat by making an insulated pine-wood box covered with three glass layers.

2.3 HOW DOES A SOLAR AIR-CONDITIONING WORKS Solar thermal collectors fixed on the top of the buildings provide thermal energy by collecting the sun’s energy on plate collectors and heating the recirculated heat transfer fluid within the system. The produced heat is then used in conjunction with e.g. absorption or adsorption air conditioner to provide a renewable source. Both ab-and adsorption process are thermally driven processes, the only difference is that, in absorption process vapor is taken by liquid while in adsorption process, vapor is attached on the porous solid material. Currently, most of the solar cooling systems are driven by absorption conditioners. However, due to simple vapor-solid operation, adsorption conditioners seem to provide a promising alternative.

Types of concentrated solar power: 

Parabolic trough

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Enclosed trough

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Fresnel Reflectors

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Dish Engine System

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Solar Power Tower

2.4 SOLAR AIR CONDITIONING

Technology

Absorption

Adsorption

DEC

Silica gel order

Refrigerant Sorption agent Cold carrier

One Stage Water Lithium Bromide Water

Two Stage Water Lithium Bromide Water

Water Silica gel Water

Cold temp. range Hot temp. range Cold output range per

6-20 degC 75-100 degC 15-20000 kW

6-20 degC 140-170 degC 170-23000 kW

6-20 degC 65-95 degC 70-350 kW

chloride 16-20 degC 55-100 degC 6-300 kW

0.6-0.7

0.5-1.0

unit COP 0.6-0.7 1.1-1.4 Table 1: summary of solar thermal cooling processes

lithium

2.5 LAYOUT OF SOLAR COOLING INSTALLATIONS A typical solar cooling system consists of a common solar thermal system made up of solar collectors, a storage tank, a control unit, pipes and pumps and a thermally driven cooling machine. Most collectors used in solar cooling systems are high efficiency collectors which are available in the market today.

Solar assisted air conditioning systems may be classified into - Closed system - Open system 2.6 MAIN COMPONENTS IN A SOLAR ASSISTED AC SYSTEM The main components in a solar air conditioning system can be divided as follows - Solar collector - which consist of flat plate collector & evacuated tube collector - Hot water & chilled water storage - Chiller – which consists of absorption & adsorption chillers.

- Cooling towers - Fan coils 2.7 POSITIONING OF SOLAR PANELS The direction and angle that the panel faces can have a big impact on its performance by affecting the amount of light that hits the panel each day through the year. Some solar panels move continuously to track the sun but most will not go to the expense and difficulty of implementing that. To get it right we have to make sure that the panels get hit by the maximum amount of light. This happens when the sun is directly above the panel.

2.7 BUILDING INTEGRIBILITY Buildings and their processes account for one half of all energy consumption. When the energy required to mine, produce, deliver and assemble materials for the construction of buildings. For developed countries to carry on enjoying the comforts sustainability must be the cornerstone for design philosophy for the years to come. Rather than reducing usage of non-renewable resources to create less pollution, we need sustainable building designs that run on renewable sources of energy to provide most/almost of their own energy needs and future pollution.

2.8 PRINCIPLES OF BUILDING INTEGRATION

Unlike any other building installation, building integrated photovoltaics can affect a lot of essential parts of the design process:  Layout and orientation  Form and Massing  Layout and height of surrounding buildings  Energy strategy  Building structure and modularity  Selection and assembly of other building materials  Capital and running costs  Construction integrity and detail  Appearance and architectural expression 3. CASE STUDIES 3.1 QATAR 2022 SHOWCASE STADIUM Project data: Year of Completion – 2010 Country – Qatar Location – Al Thumaama, Doha Capacity – 500 Seats Architect - Arup Associates, UK Solar Panels - 1600 The Qatar showcase stadium is located at Al Thumaama in the city of Doha, Qatar. The Stadium is designed as a showcase model stadium for the Qatar 2022 FIFA world cup bid by the Arup associates. Arup Associates design for 2022 FIFA World Cup Qatar Showcase is a distinctive building that was a major driver in Qatar’s sustainability plan.

3.2 KAOHSUING NATIONAL STADIUM, TAIWAN

Project data: Year of Completion – May 2009 Country – Taiwan Location – Zuoying, Kaohsiung Capacity – 55,000 Architect - Toyo ito # Solar panels – 8,844 Panels (Roof top) The Kaohsiung National Stadium formerly known as world games stadium is a multipurpose stadium in Zuoying District, Kaohsiung, Taiwan. It is currently the largest stadium in Taiwan in terms of capacity. The stadium has a capacity of 55,000 people. The stadium, designed by Japanese architect Toyo Ito, makes use of solar energy to provide its power needs. The stadium incorporates 8,844 solar panels, supported by spiraling steel girders and covering every square inch on the roof.

3.3 ESTADIO MINEIRAO, BRAZIL Project data: Year of Completion – 1965 Year of Renovation - 2010 Country – Brazil Location – Belo Horinzonte, Brazil

Capacity – 62,547 Architect – Eduardo Mendes Guimaraes (1959), BCMF (2010), GMP Certification – LEED certified 4. ACKNOWLEDGEMENT In conducting this report, I have received munificent help from many quarters, which I like to put on record here with deep gratitude and great pleasure.

First and foremost, I am highly obliged to my Dissertation Faculty in charge, Ar.Sahana and my guide Ar. Abhishek VK who allowed me to encroach upon his precious time from the very beginning of this work till the completion. His expert guidance, affectionate encouragement and critical suggestions provided me necessary insight into the research problem and paved away the way for the meaningful ending of this report work in a short duration, A special thanks goes to my father Er.Moidu MK, who gave suggestion about the topic and by providing me various articles and project reports from the companies. I have to appreciate the guidance given by other faculties and the review of the other panels. Their advices and feedback has helped me to go about the study in the right direction. I would like to express my gratitude towards my Director Mr. Nishant H. Manapure and my college Faculty of Architecture for their kind co-operation and encouragement which help me in completion of this dissertation.

REFERENCES: BOOKS 1. Jacobson, Mark Z. and Delucchi, Mark A. (2010). "Providing all Global Energy with Wind, Water, and Solar Power, Part I: Technologies, Energy Resources, Quantities and Areas of Infrastructure, and Materials”. Energy Policy.

2. "The surprising history of sustainable energy". Sustainablehistory.wordpress.com. Retrieved 201211-01.

3. "Energy Sources: Solar". Department of Energy. Retrieved 19 April 2011.

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http://seedengr.com/An%20Overview%20of%20Solar%20Assisted%20Air-Conditioning %20System.pdf http://mnre.gov.in/file-manager/UserFiles/Sun-Focus_April-June-2014.pdf http://ec.europa.eu/energy/intelligent/projects/sites/ieeprojects/files/projects/documents/solco_solar_cooling_conclusions_and_recommendations_en.pdf http://www.arupassociates.com/en/case-studies/qatar-showcase/ http://acboy.org/solar-air-conditioner/