The importance of internal heat gains - an analysis of Baumschlager Eberle’s 2226

THE IMPORTANCE OF INTERNAL HEAT GAINS an analysis of Baumschlager Eberle’s 2226

MSc Sustainable Architecture AAR4926 Integrated Energy Design Theory Report by Florian Betat

TABLE OF CONTENTS

3 3 3

4 4 7 9

10 10 15

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17 18 19 22

1. INTRODUCTION 1.1. The growing importance of IHG in efficient buildings 1.2. The problem of overdimensioning HVAC systems

2. CASE STUDY BUILDING - 2226 2.1. The context, form and layout 2.2 The heating strategy 2.3. The materials

3. ANALYSIS 3.1. The dependancy of 2226 on IHG 3.2 The imitability of the 2226 strategies in northern climates

4. DISCUSSION AND REFLECTION

5. FURTHER WORKS

6. REFERENCES

7. APPENDIX

LIST OF ABBREVIATIONS

ACH

air change rate

GHG

greenhouse gas

GWR

glazing-to-wall ratio

H

heat loss

HVAC

heating, cooling and air-conditioning

IHG

internal heat gains

LCA

life cycle assessment

NTNU

Norwegian University of Science and Technology

ABSTRACT Modern buildings tend to use less and less energy but their HVAC systems are growing ever higher and have an increasing demand of servicing and maintenance. Especially in poorer countries this can lower the possibilities of building in an energy efficient way.

Therefore, the Austrian office building “2226” by Baumschlager Eberle is analysed to find information regarding how to decrease the need of technical systems in a building without foregoing the efficiency and life quality. Furthermore it is looked at the possibility and reasonability to use such low-tech strategies as in “2226” in colder regions such as Latvia.

The results show that the heat gains from occupants and equipment are high enough to heat the case study building at any point. However, sacrifices in the efficient use of electricity and in indoor air quality have to be done during the colder season in order to lower the buildings heating demand and to increase the IHG. Such a building as “2226” without any HVAC systems would be only possible to implement in Latvia, if especially the heat losses from natural ventilation could be reduced. But the results are anyway promising as they show that only a small heating system to cover the peak loads during the winter months would be

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additionally needed. Therefore, a better use of IHG can help to lower the costs of building efficient.

1. INTRODUCTION 1.1. The growing importance of IHG in efficient buildings

Internal heat gains (IHG) are firstly caused by the heat dissipation of residents but mostly by the waste heat of electrical end-uses. One might say that electric equipment gets more and more efficient nowadays and therefore heat gains from them will soon be a story of the past. However, various studies show another trend. Yes, appliances and equipment get more efficient but they get used more. In the last two decades the energy demand per household was growing in each EU member state by at least 50 % [1] and especially in Germany, Austria and Belgium the demand is further rising. Not only in the residential, also in the secondary sector the demand is not decreasing. In offices computers account for the most electric use and IHG and while modern computers require less energy in low-power-modes, their increased processing capacity results in higher power demands and heat gains during their active time [2].

The Energy Performance of Buildings Directive (EPBD) indicates that all new buildings must be nearly zero-energy buildings by 31 December 2020, public buildings even by 31 December 2018 [3]. Following, building envelopes get significantly better insulated and the relative share of IHG is even larger. Therefore, IHG which are hard to predict accurately can have already now a large impact on buildings.

1.2. The problem of overdimensioning HVAC systems

Heating, ventilation and cooling systems (HVAC) account today for almost half of the energy consumption of buildings in developed countries. One of the problems is the rapid increase of energy demand for cooling systems in the commercial sector. Even in the mild climate of UK, nowadays more than half of the offices are built with mechanical cooling systems, as the building envelopes are tight and IHG high. [4] But also the heating systems are causing problems. A correct dimensioning for the heating installations is important in means of thermal comfort, energy consumption and costs. IHG are often not accounted as already existing heat source when dimensioning the systems, as they can be quite hard to predict, since they are highly dependent on the respective use, equipment and occupant behavior. [5] However the 2013 finished office building “2226� offers a possible solution by using the natural given IHG in a

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smart way to be able to renounce from any HVAC systems to save emissions as well as costs.

2. CASE STUDY BUILDING - 2226 2.1. The context, form and layout

FIG. 1-3

country: Austria

town: Lustenau

address: Millennium Park 20

After nearly thirty years in business, the architecture company Baumschlager Eberle had the opportunity to finish their own office building in 2013. The goal was to have a building with natural materials using less energy by having less building services since the current overload on systems and hightech insulation material results in increased maintenance and repairing costs. Furthermore, the relatively short lifetime of the systems increases the embodied energy and conflicts with the architect’s idea of a building that would last 200 years. Therefore the outcome is “2226” without any cooling or heating systems to simplify its use and to make it largely maintenance-free.

Located at the Austrian-Swiss border in the county of Voralberg, the building stands in a warm, humid, continental climate. The region has an average temperature of 9.1°C and the temperature average varies over the year between -0.7° and 18.4°C. Furthermore, the area has a characteristic of having relatively large amount of rainfall even in the driest months [6]. The rural location ensures high outdoor air quality that can be used for natural ventilation and would not require any additional air filtering. Due to the relatively mild climate, the architect had more freedom of experimentation to achieve passive house principles and reduction of housing services that would need to be installed while not needing to sacrifice the indoor comfort levels.

With its 24 × 24 × 24 meters the building stands monolithic on an elongated over 4000 square meter large plot of land in an industrial park in the town Lustenau. The six floors slightly vary from each other and create

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inconspicuous little overhangs or steps from floor to floor which break the clean white facades with its uniform

windows with thin stripes of shadows. The outer walls are, with nearly eighty centimeters, uncommonly thick as well as very airtight and the windows lay very deep in the regular window openings, emphasising the monolithic look. Each of the windows has a fixed and not to open window area but therefore narrow ventilation panels out of silver fir on the side of each.

When looking from outside one can recognize nothing more than the whitewashed, geometric facade with its narrow shadows generated by the small overhangs, as well as the wooden windows with the ventilation panels nothing else as shading systems or solar collector can be spotted, giving the building its remarkable cleanness and simplicity and therefore its charm.

The quadratic layout of the office is divided by windmill-sail like arranged double walls into three hundred square meter large rooms and a fourthed a bit smaller one including the main staircase. Flexibility is important, therefore the use of the space can change with time. Along the inner walls runs a wooden covered cable duct, which allows easy access to water and electricity and makes changes in the use easily possible. The lighting distribution in the building is done with four types of minimalistic looking luminaires, resembling more of a window daylight effect than an actual lamp. As many recently built office buildings, the emphasis is not only on the workplaces alone but as well the places to meet and take a break that improve the satisfaction and productivity of the workers. At the moment most of the building, nearly four of the six stories, is used as office with ateliers and archives. The groundfloor hosts a cafeteria and a spacious art gallery and the highest floor is used for living. [7]

FIG. 4: Floor plans ground floor

2nd floor

5

2

5

4

1

5

2 2

05

3rd floor

5 6

5 5

2226 Lustanau office building

FIG. 5

general facts architect:

Baumschlager Eberle

location:

Lustenau, Austria

planning:

2006 - 2010

construction:

2010 - 2013

footprint:

543 m²

net floor area:

2754 m²

construction costs:

2.926.000 €

cost per m²:

914 €

zoning

4th floor

1 = Cafe

5 = Open-plan office

2 = Gallery

6 = Office

3 = Living

7 = Atelier

4 = Archive

8 = Conference

5th floor

6th floor

3

3

7 7

7

8

7 3/7

3

8

3

06

7

2.2. The heating strategy

The name “2226” implies in itself the core idea of the building with its unique heating strategy. It resembles the ideal comfort temperature range between 22 and 26°C that is to be achieved by internal heat gains alone. The concept is based on getting rid of the typical office heating and cooling technics and instead focus on the office equipment that releases heat such as PC’s, copy machines, lamps etc. as well as the users themselves [8]. A single person alone releases arround 130 Watts per hour and therefore a building with around 64 users already generates noticable amount of heat. Since the buildings in the last years have become more and more airtight, it is worth to consider the internal heat gains that, if not being thought of, might cause overheating issues and increased cooling need in a building. To reduce the unwanted temperature fluctuations indoors when not as much equipment is in use, the building has an enormous thermal mass provided by the external walls that reach 76 cm of thickness as well as the concrete ceiling slabs [9].

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FIG. 6: Internal heat gain from office equipment

Furthermore, the “2226� not only has taken away a classic heating system, it also does not have any cooling or ventilation systems. Instead, sensor controlled ventilation panels are integrated in the windows that use directly the outdoor air for cooling and ventilating the indoor environment. Furthermore, in summertime the building is cooled at night time and with the help of thermal mass it keeps the temperatures in the comfort levels in the next day. To ensure the satisfaction of the users, the vents can be as well manually operated but the sensors take care to close them to prevent the building from cooling down too much. Due to the specific floor layout that excludes the use of doors, the building can be cross-ventilated. [10] While questions might arise of how well the system performs in below zero temperatures, one has to remember the location being the mild climate of Central Europe. Nevertheless, when Baumschlager Eberle was asked of the conditions in winter time, they admitted that sometimes it is needed to keep the office equipment on and running to provide a bit extra heat. [11]

FIG. 8: Window with ventilation panel

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FIG. 7: Open staircase

2.3. The materials

The main building detail characteristic separating the “2226” from other office buildings is the thickness of the external walls. The structure is built of 76 cm thick brick walls that consist of two 38 cm layers. The inner one is a load bearing layer made from vertical coring bricks and the outer layer is built up from insulating bricks. The brickwork is covered by a lime render both outside and inside. The latter contributes to CO2 absorption in the first years. The U-value of external walls is 0.13 W/m²*K. As already previously described, the windows are seated deep in the walls so in a way providing certain shading without any shading elements. Furthermore the external window ledges can store water and so contribute to reflecting daylight and distributing in the interior spaces of the building. For glazing the Pilkington Optitherm S3 windows with U-value of 0.6 W/m²*K were chosen. The interior space has concrete ceilings that perform as thermal mass and elevated floors that help to distribute the building’s infrastructure freely in the spaces as well as constitute to possible layout change in future without the need of changing the infrastructure network. The roof is out of concrete and has an U-value of 0.09 W/m²*K. [12]

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FIG. 9: Exposed brick walls during construction

3. ANALYSIS 3.1. The dependancy of 2226 on IHG

While the cooling process of the building is rather clear to understand - during hot periods night purging is used to cool down the large thermal mass of the building and to keep the indoor temperature during day time always below 26 °C - the heating process is of interest. Therefore, the analysis focuses first on the origins of IHG in the building to be able to understand later on the buildings operation principles in detail and to evaluate the feasibility of such heating strategies in colder climates.

In [FIGURE 10] one can see the results of the monitoring of one zone, which is done throughout the whole building, mainly to operate the ventilation panels. The CO2 level is measured, as well as the external and indoor temperature. The data visible is from April, having outside temperatures around 10 °C while the indoor temperature is quite constant 24 to 25 °C. The indoor air quality is according to ÖNORM EN 13779 (2008) [13] in the category IDA 1 to IDA 3, having changes in the air quality between very high and moderate level but being always hygienically acceptable. This data shows that the building can be ventilated during cool days while still being heated only by IHG. But unfortunately no data regarding colder months was available.

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FIGURE 10: Monitoring results for part Top 11 during April 2013

FIGURE 11: Heat losses of 2226 by element during workhours

nat. ventilation 64.7%

floor 4.3% roof 2.0% walls 10.1% windows (glass) 12.0% windows (frame) 6.9%

To determine the heating demand a calculation based on the heating period method from the German norms DIN V 4108-6 and DIN V 4701-10 and confirm to EU-regulations was conducted [SEE APPENDIX A]. In [FIGURE 11] one can see that the ventilation losses during the work hours are far higher than the losses through the building envelope. The walls, floor slab and roof contribute due to their excellent insulation even less to the heat losses then the windows. When looking at the results the heat losses from ventilation seem very high and one might question the concept of having no mechanical ventilation system with heat exchanger. But if one looks at the distribution of heat losses throughout a whole year [FIGURE 12], including occupant and non occupant time, the heat losses due to natural ventilation account only for one third of the total.

FIGURE 12: Heat losses of 2226 throughout a year

nat. ventilation 33.1%

building envelope 66.9%

H = 165500 kWh

As “2226” is mostly an office building it has actually more unoccupied hours than occupied ones, reducing the demand for ventilation especially during the cooler night time. But still the estimated heating demand of 165.500 kWh a year or 60 kWh per m² and year has to be compensated by IHG alone.

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It is actually surprisingly hard to find sufficient data regarding the heat output from different equipment.

FIGURE 13: Typical IHG in an office building IHG per worker in W

efficient use of equipment inefficient use of equipment

computer screen

lighting

printer

total other equipment

Austria’s ministry for sustainability and tourism has energy advising services which provide some data regarding the IHG in relation to the efficiency of use and also the state of efficiency of the equipment itself. [FIGURE 13] illustrates the dependance of IHG from equipment depending on the user behaviour. Therefore the IHG of the equipment of one office worker can range between 135 and 440 W per work hour [14]. Architect Dietmar Eberle tells by himself that in case of cold winter periods, lights, coffee and office machines get activated more often to cover the rissen heating demand [15]. More inefficient use means more heating. Additionally to the office equipment and light humans themself account for IHG. The heat input per office worker is set for the calculations according the ISO standards to 130 W per hour [16].

The following analysis is evaluating two possible heating scenarios of “2226” in relation to the outside temperatures. The large thermal mass of the building is due to simplifications not taken in account and the heating demand is directly influenced by the outside temperature. In [FIGURE 14] the graphs for the heat losses due to the building envelope and required ventilation are combined with the graphs for the possible IHG as from humans and equipment, efficient or inefficient used. This allows to gain insights how the building might operate at different temperatures. The IHG in “2226” can be regulated as described by the degree of efficiency in using equipment. Resulting the building will have during use a minimum of 17 kWh IHG and a maximum of 36,5 kWh. This means that the IHG are higher then the heating demand of the building at outdoor temperatures above 15 °C. In

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this case the building has to be ventilated more then required to keep the indoor temperatures stable and night

FIGURE 14: Heating scenario 1 ventilating as much as possible / more inefficent use of equipment

H in kWh

10 0% 90 % of re q.

80 ve % nt ila 70% tio n 60% 50% 40% 30% 20% 10%

estimated IHG

total IHG - inefficient use of equipment

0%

total IHG - efficient use of equipment IHG - humans

increasing indoor temperature

efficient use of equipment

ventilating more than required

increasing inefficiency in use of equipment

ventilating as required

inefficient use of equipment

less ventilation as required

T external in °C

purging be useful. For the temperatures below 15 °C exist two heating options. One were it is looked at to ventilate as much as required as long as possible (heating scenario 1 = HS 1) [FIGURE 14] and another were the equipment is used as efficient as possible (heating scenario 2 = HS 2) [FIGURE 15]. For HS 1 the equipment is used more and more inefficient till 8 °C outdoor temperature, till then ventilation is functioning as required. But at 8 °C outdoors the border is reached, where the heat losses from ventilation are greater than the maximum IHG. To keep the temperature inside in the comfort level, it has to be ventilated less than required and the equipment has to be

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used inefficient at outdoor temperatures under 8 °C. In HS 2 the equipment is used as efficient as possible above

FIGURE 15: Heating scenario 2 most efficient use of equipment / less ventilation

H in kWh

10 0% 90 % of re q.

80 ve % nt ila 70% tio n 60% 50% 40% 30% 20% 10%

estimated IHG

total IHG - inefficient use of equipment

0%

total IHG - efficient use of equipment IHG - humans

increasing indoor temperature

efficient use of equipment

ventilating more than required

efficient use of equipment

ventilating less as required

less efficient use of equipment

no ventilation

T external in °C

outdoor temperatures of 2 °C. But at this point there is no ventilation at all. For all outdoor temperatures under two degrees the equipment gets used less efficient to compensate the rising heating demand. HS 1 is probably the more reasonable scenario as it ensures good air quality for a longer time. This analyse also showed that heating the building only by IHG is possible even at extreme cold temperatures, but as colder it gets, the more compromises have to be done regarding efficient electricity use and required ventilation. Thus, the special wall

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finish out of CO2 absorbing lime could contribute to a reduced ventilation demand slightly.

3.2. The imitability of the 2226 strategies in northern climates

The weather conditions at the location of “2226” in Lustenau are warm and moderate. The yearly average temperature is 9.1 °C, the coldest month is January with -0.7 °C in average and the warmest July with 18.4 °C. As example for northern climate is chosen Riga in Latvia. The weather there is cold and moderate with an average annual temperature of 6.4 °C. Coldest it gets in February with average -4.8 °C and the warmest month with 17.1 °C is July. [17] Apparently, Rigas weather is colder and the temperature fluctuations are higher as can be seen in [FIGURE 16].

This is challenging the concept of only heating with IHG. In [FIGURE 17] can be seen that the building “2226” in Lustenau can function with adequate ventilation for nearly seven months, from beginning of April till end of October. Night purging might be needed from mid of June till end of August. Only in December and February the ventilation level is critical but no extra heating is needed to keep the indoor temperature stable.

If one would build the same building as the “2226” in Riga [FIGURE 18] it would need nearly no night purging. But the building would work with sufficient ventilation only for a bit more than five months, from May till beginning of October. From the first days of December till end of March the IHG of a building such as “2226” are not enough to cover the heat losses through the building envelope, even not without ventilation. Consequently this means that the principles of “2226” cannot be only copied and work in another climate. Solutions regarding sufficient

FIGURE 16: Average temperature in Lustenau, AT and Riga, LV T in °C avg T - Lustenau avg T range - Lustenau

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avg T - Riga avg T range - Riga

ventilation in colder climates have to be found and additional small heating systems for the peak loads during winter season might be required to fulfill the heating requirement. Nevertheless it is good to see to what extent IHG can heat a building. By having a good insulated building envelope and a smart use of IHG the required heating system can be significantly smaller.

FIGURE 17: Heating demand and IHG in Lustenau, AT kWh per month 30000

Heating demand with required ventilation Heating demand without ventilation

25000

20000

IHG humans IHG humans + efficient use of equipment IHG humans + inefficient use of equipment

15000

reduced ventilation no ventilation / need of add. heat source

10000

5000

0

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

FIGURE 18: Heating demand and IHG in Riga, LV kWh per month 30000

25000

20000

15000

10000

5000

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

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0

4. DISCUSSION AND REFLECTION

The research and analyse shows that the building “2226” is extremely well adjusted to its location, surrounding climate and its use. Firstly, the climate in Lustenau is mild enough to heat the building throughout the whole year only with IHG from usal office work and in summer the temperatures are not too high to use only passive night purging. The outside air quality is very good, allowing natural ventilation without any needs of filters. Furthermore, the site in an small industrial park at the border of the small town Lustenau makes the square meter price comparatively cheap, allowing 78 cm thick outer walls and increased ceiling heights, something to rethink if planning for dense urban areas.

Heating only with IHG is possible, this is shown by the built example itself, as well as the conducted analyse.

However, the analyse allowed to understand the operating principles of the building better. It revealed that sacrifices in efficient use of electricity and in indoor air quality have to be done during the colder season to lower the heating demand and to increase the IHG. With an inefficient but not yet wasteful use of office equipment the heat gains needed during the coldest possible periods could be just reached.

The question might arise if it is a good idea to use equipment inefficient in order to have a building without a small peak load heating system. In terms of emission reduction this topic has to be looked at with further help of LCA. But the strategy to have no heating system at all, as used in “2226” has definitely benefits.

Firstly, the construction price is lower as no system has to be built in. The office equipment used for heating would be needed anyway. In what extent the maintenance costs of a heating system can be offset during the use time of the building remains a question, as inefficient use of electric equipment might shorten their lifetime. But it is definitely a strategy that increases the possibilities of building efficient also in poorer countries.

The second benefit of having no HVAC systems is, that the building remains very flexible in terms of use change or retrofitting. The topic of flexibility and lifetime of the building was very important for the architects. The open floor plan, easy to access ducts, elevated floors and high ceilings allow unproblematic changes in layout or function and upgrading of the existing housing infrastructure. In most of the cases houses get torn down because they cannot meet such cost effective flexibility. The average lifetime of new built buildings in Europe is said to be arround 60 years [18]. In Japan it is only half that time [19]. GHG emissions would be reduced noticeably if buildings would last longer. “2226” is planned to stand at least 200 years due to its used materials, flexibility and

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adaptability for changing use and new technology.

Implementing the strategies from “2226” in colder climates, such as Latvia causes some problems. The heat input from office equipment is not high enough to heat the building up during the coldest months, even with such a well insulated building envelope. Further research should therefore focus on strategies how to decrease the heat losses for example during the colder and often unoccupied nights, whether it be with usal curtains or other more advanced systems. Also heat recovery systems for natural ventilation should be looked at further. In case good and cost effective solutions are found and the heat losses could be lowered notecible, heating only with IHG would be also widely possible in Latvia, allowing to build efficient for a little money.

But even if additional HVAC systems are needed in order to reach the wanted space quality, it is important to consider the IHG which can occur in a building and find ways how to use them best. Reducing the size of building services and a simplification of them allows to save money, reduce emissions and prolong the buildings lifetime due to an increased flexibility.

Additionally, the strategies of “2226” could be implemented in more different climates, if the users would tolerate larger fluctuations of temperature. Having a possible temperature range of more than 4 °C, for example between 18 and 26 would make such concept way more feasible. Of course, this is getting immediately a discussion about personal comfort and preferences, but examples as the Antivilla from architect Arno Brandlhuber offer possible solutions how to live with the seasons instead of using a lot of energy to hold the temperatures in every corner of the building constant [20].

5. FURTHER WORK Additional work has to be done to find solutions how to use low-tech strategies in colder climates in order to lower the investment cost for efficient buildings and therefore encourage more people to build them. Thus, further research is needed regarding the following questions: - How heat losses of buildings can be reduced during the non occupant times? (curtain systems for windows, etc.)

- In what way is natural ventilation combinable with heat recovery systems?

- Is it saving emissions in long term when using electric equipment inefficient to increase the IHG instead of

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investing in a small peak load heating system?

6. REFERENCES

Elsland, R., Peksen, I., Wietschel, M. (2014), “Are internal heat gains underestimated in thermal performance evaluation of buildings?”, page 33, Elsevier Ltd.

[2]

Menezes, A. C. et al. (2014), “Estimating the energy consumption and power demand of small power equipment in office buildings”, page 200, Elsevier B.V

[3]

European Commission. (2018), “Energy Performance in Buildings Directive”. [Online].[Accessed September 20 2018]. Available from: https://ec.europa.eu/energy/en/topics/energy-efficiency/buildings

[4]

Pérez-Lombard, L., Ortiz, J., Pout, C. (2007), “A review on buildings energy consumption information”, page 398, Elsevier B.V

[5]

CIBSE ASHRAE Technical Symposium. (2012), “Review of Benchmarks for Small Power Consumption in Office Buildings”, Imperial College, London, UK

[6]

CLIMATE-DATA.ORG. n.d., “KLIMA & WETTER IN LUSTENAU”. [Online]. [Accessed September 20 2018]. Available from: https://de.climate-data.org/location/22968/

[7]

Baumschlager Eberle Architekten. n.d., “2226”. [Online]. [Accessed September 15 2018]. Available from: https://www.baumschlager-eberle.com/werk/projekte/projekt/2226/

[8]

Wienerberger. n.d., “Winner Grand Prize & Special Solution: 2226, Austria”. [Online]. [Accessed September 15 2018]. Available from: https://clay-wienerberger.com/expertise/winner-grand-prize-special-solution-2226-austria

[9]

BDONLINE. (2014), “2226 Lustenau office building”. [Online]. [Accessed September 16 2018]. Available from: https://www.hughstrange.com/pdf/writing/baumschlagereberle_2226lustenauofficebuilding_bdtech_jan2014.pdf

[10]

Vorarlberger Architektur Institut. (2013), “Architektur vor Ort 105 - Haus 2226”. [Online]. Accessed September 16 2018]. Available from: https://v-a-i.at/veranstaltungen/architektur-vor-ort/architektur-vorort-105/avo-105buerohaus-2226.pdf

[11]

espazium.ch. (2015), “Passivität wörtlich genommen”. [Online]. [Accessed September 20 2018]. Available from: https://www.espazium.ch/passivitt-wrtlich--genommen

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[1]

BDONLINE. (2014), “2226 Lustenau office building”. [Online]. [Accessed September 16 2018]. Available from: https://www.hughstrange.com/pdf/writing/baumschlagereberle_2226lustenauofficebuilding_bdtech_jan2014.pdf

[13]

Ministerium für ein Lebenswertes Österreich. (2017), “RICHTLINIE ZUR BEWERTUNG DER INNENRAUMLUFT”.

[Online]. [Accessed September 18 2018]. Available from:file:///C:/Users/flori/Downloads/Teil%207%20-%20CO2_2017.pdf

[14]

O.Ö. Energiesparverband. n.d., “Checkliste für den Einkauf von energie-effizienten Bürogeräten”. [Online].[Accessed October 2 2018]. Available from: https://www.energie-sparverband.at/fileadmin/redakteure/ESV/Info_und_ Service/Publikationen/Checkliste_Buerogeraete.pdf

[15]

espazium.ch. (2015), “Passivität wörtlich genommen”. [Online]. [Accessed September 20 2018]. Available from: https://www.espazium.ch/passivitt-wrtlich--genommen

[16]

The Engineering ToolBox. n.d., “Metabolic Heat Gain from Persons”. [Online]. Accessed September 19 2018].

Available from: https://www.engineeringtoolbox.com/metabolic-heat-persons-d_706.html

[17]

CLIMATE-DATA.ORG. n.d., “KLIMA & WETTER IN RIGA”. [Online]. [Accessed September 20 2018]. Available from: https://de.climate-data.org/location/372/

[18]

brandondonnelly. n.d., “The life expectancy of buildings”. [Online]. Accessed September 24 2018]. Available from: http://brandondonnelly.com/post/128489870433/the-life-expectancy-of-buildings

[19]

Braw, E. (2014), ”Japan's disposable home culture is an environmental and financial headache”, The Guardian, 2 May. [Online]. [Accessed September 26 2018]. Available from: https://www.theguardian.com/sustainablebusiness/disposable-homes-japan-environment-lifespan-sustainability

[20]

Brandlhuber, A., Schulz, A. (2012), “Das projekt „Antivilla“ von Brandlhuber+”, Arch+, vol. 208, page 170-75.

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[12]

Malmquist, E. B. n.d., ”2226 – Ikke noe hokus pokus”. [Online].[Accessed September 26 2018]. Available from: https://www.arkitektur-n.no/artikler/ikke-noe-hokus-pokus

[FIG. 1]

Own representation based on Melbournechapter. n.d., “image stock Map of europe at getdrawings com free”. [Online].[Accessed September 28 2018]. Available from: https://melbournechapter.net/ explore/lines-drawing-contemporary/#gal_post_6278_drawing-map-1.png

[FIG. 2]

Own representation based on Openclipart. n.d., “Empty map of Austria with borders of the States”.

[Online]. [Accessed September 28 2018]. Available from: https://openclipart.org/detail/268340/empty-map-of-austria-with-borders-of-the-states

[FIG. 3]

Own representation based on Malmquist, E. B. n.d., ”2226 – Ikke noe hokus pokus”. [Online]. [Accessed September 28 2018]. Available from: https://www.arkitektur-n.no/artikler/ikke-noe-hokus-pokus

[FIG. 4]

Own representation based on Malmquist, E. B. n.d., ”2226 – Ikke noe hokus pokus”. [Online]. [Accessed September 29 2018]. Available from: https://www.arkitektur-n.no/artikler/ikke-noe-hokus-pokus

[FIG. 5]

Malmquist, E. B. n.d., ”2226 – Ikke noe hokus pokus”. [Online].[Accessed October 2 2018]. Available from: https://www.arkitektur-n.no/artikler/ikke-noe-hokus-pokus

[FIG. 6]

Malmquist, E. B. n.d., ”2226 – Ikke noe hokus pokus”. [Online].[Accessed October 2 2018]. Available from: https://www.arkitektur-n.no/artikler/ikke-noe-hokus-pokus

[FIG. 7]

Malmquist, E. B. n.d., ”2226 – Ikke noe hokus pokus”. [Online].[Accessed October 2 2018]. Available from: https://www.arkitektur-n.no/artikler/ikke-noe-hokus-pokus

[FIG. 8]

Malmquist, E. B. n.d., ”2226 – Ikke noe hokus pokus”. [Online].[Accessed October 2 2018]. Available from: https://www.arkitektur-n.no/artikler/ikke-noe-hokus-pokus

[FIG. 9]

Malmquist, E. B. n.d., ”2226 – Ikke noe hokus pokus”. [Online].[Accessed October 2 2018]. Available from: https://www.arkitektur-n.no/artikler/ikke-noe-hokus-pokus

[FIG. 10]

Own representation based on Malmquist, E. B. n.d., ”2226 – Ikke noe hokus pokus”. [Online]. [Accessed October 1 2018]. Available from: https://www.arkitektur-n.no/artikler/ikke-noe-hokus-pokus

[FIG. 11]

Own representation

[FIG. 12]

Own representation

[FIG. 13]

Own representation based on O.Ö. Energiesparverband. n.d., “Checkliste für den Einkauf von energieeffizienten Bürogeräten”. [Online].[Accessed October 2 2018]. Available from: https://www.energiesparverband.at/fileadmin/redakteure/ESV/Info_und_Service/Publikationen/Checkliste_Buerogeraete.pdf

[FIG. 14]

Own representation

[FIG. 15]

Own representation

[FIG. 16]

Own representation

[FIG. 17]

Own representation

[FIG. 18]

Own representation

21

COVER

7. APPENDIX A: Data for calculation gross floor area

3021 m²

volume

13158 m³

dimensions

24 m length × 24 m width × 24 m hight

number of floors

6

U-values floor

0.19 W/m²K

roof

0.09 W/m²K

walls

0.14 W/m²K

windows (glazing)

0.7 W/m²K

windows (frame)

1.2 W/m²K

opening percentage

24%

internal temperatures

22°C - 26°C

fresh airflow rates

72 m³/h per person

natural ventilation

through opening

number of occupants

64

occupancy density

47.2 m² per person

The total fabric heat loss is the sum of all U-values of the elements of the external fabric multiplied by their area and the temperature difference between inside and outside.

H f = (ΣU×A) × ΔT H f = 543m²×0.19W/m²K+543m²×0.09W/m²K+1751m²×0.14W/m²K+414.75m²×0.7W/m²K+138.25m²×1.2W/m²K H f = 853.4 W/K The ventilation losses are determined according to DIN EN 13779. Therfore, the ACH in a non-smoking room with high air quality is 72 m³/h per person.

H v = 0.34 × V × n × ΔT H v = 0.34 × 72m³/h × 64 × ΔT

22

H v = 1566.72 W/K