Green Office Buildings Low Energy Demand through Architectural Energy Efficiency

114 Pages·2013·34.76 MB·English

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Young Cities Research Paper Series, Volume 08
Green Office Buildings
Low Energy Demand through
Architectural Energy Efficiency
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Universitätsverlag der TU Berlin Road, Housing & Urban Development Gr
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ISSN 2193-6099 (Print) ISBN 978-3-7983-2578-4 (Print) Research Center Farshad Nasrollahi
8
ISSN 2193-6102 (Online) ISBN 978-3-7983-2579-1 (Online) ISBN 978-600-5392-82-1 0

Green Office Buildings
Low Energy Demand through
Architectural Energy Efficiency
Young Cities Research Paper Series, Volume 08
Farshad Nasrollahi
Young Cities Research Paper Series, Volume 08 Young Cities Research Paper Series
Edited by Technische Universität Berlin and Editors: Rudolf Schäfer, Farshad Nasrollahi, Holger Ohlenburg,
Road, Housing & Urban Development Research Center, Tehran Cornelia Saalmann, Florian Stellmacher
German-Iranian Research Project List of Volumes
Young Cities 01 Accomplishments and Objectives (in Farsi)
Developing Energy-Efficient Urban Fabric in the Tehran-Karaj Region Rudolf Schäfer, Tayebeh Parhizkar, Farshad Nasrollahi,
Holger Ohlenburg, Ghazal Raheb, Florian Stellmacher (Eds.)
Contact Germany Contact Iran
Young Cities Project Center BHRC Road, Housing & Urban 02 Accomplishments and Objectives (in English)
Technische Universität Berlin Development Research Center Rudolf Schäfer, Farshad Nasrollahi, Holger Ohlenburg,
Secr. A 66 P.O. Box 13145-1696 Florian Stellmacher (Eds.)
Straße des 17. Juni 152 Sheikh Fazlollah Noori Highway
10623 Berlin | Germany Tehran | Islamic Republic of Iran 03 The Shahre Javan Community Detailed Plan
www.youngcities.org www.bhrc.ac.ir Elke Pahl-Weber, Sebastian Seelig, Holger Ohlenburg (Eds.)
04 Energy Efficient Housing for Iran
Farshad Nasrollahi, Philipp Wehage, Effatolsadat Shahriari,
Abbas Tarkashvand
Design/Typesetting büro-d | Communication Design Berlin
05 Urban Challenges and Urban Design
Elke Pahl-Weber, Sebastian Seelig, Holger Ohlenburg,
Publisher
Nadine Kuhla von Bergmann (Eds.)
Universitätsverlag der TU Berlin BHRC
Universitätsbibliothek P.O. Box 13145-1696
06 Construction Competencies and Building Quality
Fasanenstr. 88 Sheikh Fazlollah Noori Highway
Bernd Mahrin, Johannes Meyser (Eds.)
10623 Berlin | Germany Tehran | Islamic Republic of Iran
www.univerlag.tu-berlin.de www.bhrc.ac.ir
07 New Towns — Promises Towards Sustainable Urban Form
ISSN 2193-6099 (Print) ISBN 978-600-5392-82-1 Mohammad Reza Shirazi
ISSN 2193-6102 (Online)
ISBN 978-3-7983-2578-4 (Print) 08 Green Office Buildings
ISBN 978-3-7983-2579-1 (Online) Farshad Nasrollahi
Simultaneously published online on the Digital Repository
of the Technische Universität Berlin
URL http://opus.kobv.de/tuberlin/volltexte/2013/4047/
URN urn:nbn:de:kobv:83-opus-40476
[http://nbn-resolving.de/urn:nbn:de:kobv:83-opus-40476]
All texts are based on scientific research performed within the Bibliographic information published by the Deutsche Nationalbibliothek
Young Cities Project. All pictures, tables and graphics are courtesy The Deutsche Nationalbibliothek lists this publication in the Deutsche
of the respective article’s authors, unless otherwise mentioned. Nationalbibliografie; detailed bibliographic data are available in the
Internet at http://dnb.dnb.de
© 2013 All rights reserved by the Technische Universität Berlin.
4
Acknowledgements
The eighth volume of the “Young Cities Research Paper Series” with I am also very grateful to Cornelia Saalmann, my colleague on the
the title “Green Office Buildings — Low Energy Demand through Board of Editors of the Young Cities Research Paper Series, for her kind
Architectural Energy Efficiency” presents the results gained within the cooperation and reliable work in publishing this volume.
Young Cities Research Project, which was sponsored by the German Finally, I would like to thank Sharon Heidenreich for her outstand-
Federal Ministry of Education and Research (BMBF). I would therefore ing proofreading of this volume and büro-d for the layout and graphic
like to express my sincere thanks to the Federal Ministry of Education design.
and Research for its financial support. My thanks are also due to my uni-
versity, bearing the primary responsibility of the project, and the heads Farshad Nasrollahi
of partner institutions, among others the Berlin Institute of Technology TU Berlin
(Technische Universität Berlin), as well as Prof. Dr. Rudolf Schäfer, di-
rector of the Young Cities project, for contributing towards the success-
ful accomplishment of the project.
The studies and research regarding energy efficiency in office build-
ings published in this volume was performed at the Chair of Building
Technology and Architectural Design (Fachgebiet Gebäudetechnik
und Entwerfen). I therefore owe special thanks to Prof. Dipl.-Ing. Claus
Steffan, the Chairman of this section, for his scientific support in the
field of energy efficiency as well as his helpful advice on the design of the
New Generation Office Building.
Special thanks go to my student assistant in 2012, Alexander Wanit-
schke, for participating in the studies on energy-efficient heating and
cooling systems and drawing the concepts of the HVAC systems. I am al-
so very grateful to another one of my student assistants, Jakob Kress, for
his assistance in preparing design drawings and rendering the perspec-
tives of the New Generation Office Building. I would furthermore like
to thank Zofia Bogucka, also a student assistant, for her help in drawing
some of the building concepts.
The German side of the Young Cities project
is partly funded by German Federal Ministry
of Education and Research (BMBF).
5
Table of Contents
Forewords 3 Window Area . . . . . . . . . . . . . . 30
R. Schäfer . . . . . . . . . . . . . . . 10 3.1 Window-to-wall ratios in all façades without shading devices . 30
C. Steffan . . . . . . . . . . . . . . . 11 3.2 Window-to-wall ratios in façades with external blinds . . . 33
3.3 Comparison of window-to-wall ratios with and without
I Climate Analysis . . . . . . . . . . . . . 12 external shading devices . . . . . . . . . . . 35
1 Introduction . . . . . . . . . . . . . . 14 3.4 Window-to-wall ratio of the north-facing façade . . . . . 35
3.5 Window-to-wall ratio on east and west façades . . . . . 37
2 Climate Factors of Hashtgerd New Town . . . . . . 15 3.6 Conclusion . . . . . . . . . . . . . . . 39
2.1 Air temperature. . . . . . . . . . . . . . 15
2.2 Air humidity . . . . . . . . . . . . . . 16 4 Shading Devices . . . . . . . . . . . . . 40
2.3 Wind . . . . . . . . . . . . . . . . 16 4.1 Overhangs . . . . . . . . . . . . . . . 40
4.2 External blinds . . . . . . . . . . . . . . 41
3 Climate Data Analysis. . . . . . . . . . . . 18 4.3 Conclusion . . . . . . . . . . . . . . . 43
3.1 Psychrometric chart analysis . . . . . . . . . . 18
3.2 Temperature timetable plot . . . . . . . . . . 20 III New Generation Office Building . . . . . . . . 44
3.3 Sun chart and sun shading chart . . . . . . . . . 20 1 Goals and Strategies . . . . . . . . . . . . 46
II Architectural Energy Efficiency . . . . . . . . 22 2 Research Method . . . . . . . . . . . . . 47
1 Architectural Energy Efficiency. . . . . . . . . 24
1.1 Optimizing criteria. . . . . . . . . . . . . 24 3 Building Site . . . . . . . . . . . . . . 47
1.2 Conclusion . . . . . . . . . . . . . . . 25 3.1 Efficient use of building site . . . . . . . . . . 48
1.3 Application of Architectural Energy Efficiency in Iran . . . 25
4 Theoretical Inquiry . . . . . . . . . . . . 51
2 Orientation. . . . . . . . . . . . . . . 26
2.1 Heating energy demand . . . . . . . . . . . 26 5 Physical (Spatial) Planning . . . . . . . . . . 52
2.2 Cooling energy demand . . . . . . . . . . . 26 5.1 Room schedule according to German regulations. . . . . 52
2.3 Lighting energy demand . . . . . . . . . . . 27 5.2 Room schedule according to Iranian regulations . . . . . 55
2.4 Comparison between heating, cooling and lighting energy 5.3 Comparison of room schedules. . . . . . . . . . 56
demand . . . . . . . . . . . . . . . . 27
2.6 Total energy demand . . . . . . . . . . . . 28 6 Building Materials. . . . . . . . . . . . . 58
2.7 Primary energy demand . . . . . . . . . . . 28
2.8 Comparison of total energy demand and primary energy demand 29 7 Thermal Comfort . . . . . . . . . . . . . 58
2.9 Conclusion . . . . . . . . . . . . . . . 29
6
8 Optimization of Thermal Resistance . . . . . . . 58 IV Energy-efficient Heating and Cooling Systems. . . . 94
1 Introduction . . . . . . . . . . . . . . 96
9 Architectural Design . . . . . . . . . . . . 60
2 Conventional Heating and Cooling Systems . . . . . 97
10 New Generation Office Building — Concepts . . . . . 61 2.1 Heating . . . . . . . . . . . . . . . . 97
10.1 Optimal urban form . . . . . . . . . . . . 61 2.2 Cooling . . . . . . . . . . . . . . . . 97
10.2 Optimal building form . . . . . . . . . . . . 62
10.3 Innovative fixed shading devices . . . . . . . . . 63 3 Solar Heating and Cooling Systems . . . . . . . . 98
10.4 Natural ventilation . . . . . . . . . . . . . 64 3.1 Solar thermal system . . . . . . . . . . . . 99
10.5 Hybrid solar heating through solar reflectors. . . . . . 64 3.2 The f-chart method. . . . . . . . . . . . . 100
10.6 Mechanical ventilation system with heat recovery . . . . 66 3.3 Application to the New Generation Office Building . . . . 100
10.7 Extensive green roof . . . . . . . . . . . . 67 3.4 Economic assessment . . . . . . . . . . . . 101
10.8 Semi-transparent architecture. . . . . . . . . . 68 3.5 Sensitivity analysis. . . . . . . . . . . . . 102
11 Energy Demands of the New Generation Office Building . . 69 4 Conclusion . . . . . . . . . . . . . . . 103
12 Calculation of CO2 Emissions. . . . . . . . . . 71 V Appendix . . . . . . . . . . . . . . 104
List of References . . . . . . . . . . . . . 105
13 Architectural Plans and Perspectives . . . . . . . 73 List of Figures . . . . . . . . . . . . . . 106
List of Tables . . . . . . . . . . . . . . 110
Young Cities Project Consortium . . . . . . . . 111
About the Author . . . . . . . . . . . . . 112
7
Abstract
Due to the depletion of fossil fuels and their environmental damages, re- As the architectural design affects the heating and cooling as well
duction of global energy consumption is crucial. As the buildings are re- as the lighting energy demands of buildings, the criteria for selecting the
sponsible for about 40% of global energy consumption, introduction and best variant is best based on the total heating, cooling and lighting energy
implementation of energy-efficient buildings can reduces the total ener- demand, or the primary energy demand, the CO emissions, energy costs
2
gy demand. or life cycle costs for all three energy demands.
The first step towards creating an environmental design and identi- Architectural Energy Efficiency, as a method for optimizing the ar-
fying the possibilities for climate responsive architecture should always chitectural design, can be applied to different building types and cli-
be an analysis of the climatic data. A variety of tools are nowadays avail- mates to develop a set of energy saving guidelines for architects and
able to understand the climate conditions and create an energy-efficient building designers.
design. These include graphical means such as the building bio-climatic In this publication, Architectural Energy Efficiency is implemented
chart, the psychrometric chart, wind wheels, sun charts and sun shading in office buildings in the climatic conditions of the Tehran region.
charts, are required. The study has shown that the optimum orientation for a minimum
The first chapter of this publication shows how the climate data total and primary energy demand is the south orientation. The primary
must be analysed and which conclusions can be drawn from these anal- energy demand of north-facing office buildings is also fairly low.
yses for an environmental design. As the research findings presented in According to the results regarding the window area, the cardinal di-
this book are elaborated for Hashtgerd New Town, as the location for the rection can significantly affect the building’s energy demand. For a min-
case study project, the climatic conditions of this particular city are used imum total energy demand, the optimum window-to-wall ratios for the
as a basis. The studies have shown that passive solar heat gains and inter- south, east/west and north-facing facades are 60%, 10 % and 30 % respec-
nal heat gains are very important for heating buildings, but that shading tively. Buildings with external blinds have their lowest total and primary
devices at windows and natural ventilation are also very important mea- energy demands at a window-to-wall ratio of 60%. The proportion of win-
sures for cooling. In Hashtgerd New Town, evaporative cooling suffices dow area for each orientation should differ; the optimum window-to-wall
to meet almost the total cooling requirements. ratios for the south, east/west and north-facing facades are 60%, 10 % and
Due to the fact that energy savings through cost and energy-inten- 30 % respectively.
sive measures can only be achieved with a great consumption of resourc- The results regarding shading devices show that large overhangs and
es and CO emissions for their production, it is first of all necessary to an increase of overhang depth raise the total energy demand of office
2
apply cost and resource-efficient measures to save energy in buildings. buildings. Office buildings with external blinds require less energy than
Architectural Energy Efficiency is a parametric method of energy saving office buildings without any blinds; however, this is only the case if the
which separately studies the effects of various energy-related architec- blinds are controlled effectively.
tural factors on the energy demands of buildings. Dynamic energy sim- The third chapter presents the design process of the New Generation
ulation methods are used to find the optimum value for each of the ar- Office Building as an energy and cost-efficient office building. In compar-
chitectural factors, including orientation, building elongation, building ison to an average office building, the energy-efficient design principles,
form, opening ratio in different orientations, sun shading, natural ven- which resulted from the application of Architectural Energy Efficiency
tilation etc. in this pilot project, led to energy savings of 50%. Some further energy
8
saving concepts have been applied in this green office building for addi-
tional energy savings. These include an optimal urban and building form,
innovative fixed shading devices, a combination of natural ventilation and
evaporative cooling, solar reflectors, a mechanical heat recovery system
and extensive green roofs.
The last part of the book explores the energy and cost efficiency of
heating and cooling systems for energy-efficient office buildings in the
climate conditions of Hashtgerd New Town and, in particular, for the
New Generation Office Building, as a case study building. The research
considers the suitability of solar heating and solar cooling systems in Iran
from an economic point of view and determines the optimum area of the
solar collector, the size of the buffer tank and the slope of the panels for
the New Generation Office Building. The results show that solar energy
systems, in place of conventional systems, are not always feasible, since
the prices of fossil fuels are still relatively low in Iran, even after reduc-
ing the energy subsidies. From an economic point of view, it is therefore
more suitable to install a gas heater for heating and an evaporative cooling
system for cooling in Iran’s current economic conditions. The installation
of a subsoil heat exchanger and/or an air-to-air heat exchanger is always
worthwhile, as it decreases the heating and cooling energy demands as
well as the size of the HVAC system.
Technische Universität Berlin
Building Technology and Architectural Design
Prof. Claus Steffan
9
Forewords
This publication presents the research results in the field of energy ef- The publication also includes the planning process for developing an
ficiency in buildings. It illustrates the required steps towards an energy energy and cost-efficient office building and introduces some further in-
efficient building design, including the analyses of the climate data at the novative energy saving concepts, which are implemented in the scheme.
particular location, the building’s behavior regarding different architec- The author also presents a general concept for the energy-efficient heat-
tural factors, the architectural design process as well as the selection of ing and cooling of office buildings and studies the possibilities of using
a suitable energy-efficient HVAC system. The research was elaborated solar heating and cooling in the climatic and economic situations of the
in the context of the German-Iranian research project „Young Cities— research area.
Developing Energy-Efficient Urban Fabric in the Tehran-Karaj Region“. Even though an example climate is applied in the New Generation
Architectural Energy Efficiency, as an innovative method of energy Office Building to study Architectural Energy Efficiency, the method of
saving, is a parametric method which studies the effects of various archi- energy efficiency as well as the design process can be transferred to other
tectural factors on the energy demand of buildings. The approach uses climatic areas, such as in MENA region.
dynamic energy simulation to identify the optimum value for each archi- The study also shows that the concept of Architectural Energy
tectural factor from an energy efficiency point of view. It is according to Efficiency is a valuable and attractive approach in all situations where the
these factors that the architectural design affects the heating and cooling aim is to decrease the energy demand of buildings and the application of
as well as the lighting energy demands of buildings. Thus, Architectural cost-intensive measures is not economically viable. This book should be-
Energy Efficiency is a way to minimize the consumption of resources as come essential reading for all architects and a standard reference for ev-
well as the building costs. The measures of this approach can contribute erybody in the construction business.
towards cost-neutral energy savings.
The publication focuses mainly on office buildings; and, among the Prof. Dr. Rudolf Schäfer
pilot projects which were conceptualized as the main methodological TU Berlin
approach and tool in the Young Cities project, there is an office build-
ing designed for the local branch of the Iranian New Town Development
Corporation in the emerging new town Hashtgerd.
Prior to every design, the climatic data of the region should be an-
alyzed in order to determine the possibilities for energy savings, in this
case it is the climate of Hashtgerd.
The study then presents a systematic concept of Architectural Energy
Efficiency, detailing the factors affecting the energy demands of build-
ings and elaborating the criteria for selecting the best variant in terms of
the different energy carriers that provide heating, cooling and lighting,
such as the primary energy demand, CO emissions, energy costs, life cy-
2
cle costs and others.This approach is specified in greater detail in the de-
sign of the New Generation Pilot Project Office Building.
10