Design with Sun, for an office building in Aurangabad, India


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it is research work giving considerations for Sun for designing an office building for Aurangabad city, India.

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Design with Sun, for an office building in Aurangabad, India

  1. 1. Design with Sun - A Solution for Envelope design (For an office building in Aurangabad) BY SUVIDHA SAGAVEFINAL YEAR M.ARCH ENVIRONMENTAL (2010 (2010-11) DR. B. N. COLLEGE OF A RCHITECTURE, PUNE. SUVIDHA Hewlett-Packard Packard [Pick the date]
  2. 2. ‘Design with Sun’ – A solution for envelope Design ABSTRACT Life existed in sync with natural sources of energy, in prehistoric era. As Napoleon says, Men are moved by two levers only: fear and self interest. Hence, the journey to find alternative for his needs, he started looking towards sun, wind and water and his immediate environment. Sun, became the focal point of all his daily activities, right from stating the time of day or designing his shelter. In every civilization, from Egyptian to Mesopotamian, Sun became an icon and symbolized god, due to its effects of it year around. Indian architecture developed on the principles of Vastu, which indeed considers climatic factors and Sun became a crucial factor for designing. All the traditional techniques strategically implemented use of daylight. But Gradual development and westernization of Indian concepts and architecture, lead to lesser intake of natural elements and increased use of technology. The rat race for globalization has prompted nations, to industrialize and develop. In the long run, nations have compromised with their traditional concepts and have depleted their sources. Quoting napoleon, a man will fight harder for his interests than for his rights. The use of technology for tapping non- conventional sources came in when the conventional sources were depleted. On a global scale, the third world nations were the ones, who had to take steps to pay the price of industrialization of western nations. India, which is one of the developing nations, and can impact global ecology and economics, is being under pressure to adopt clean technology. Favourable location of India in tropical zone, works as an advantage to tap different non – conventional source – with Sun as an abundant source. The geographical variations, and radiations received allows different kinds of technology to be developed for different regions. Architectural practice today evolves designs that ignore the energy performance and comfort parameters of the building during the design stage, leaving aside few exceptions. Buildings are built and then solutions are applied to achieve these parameters. With the growing awareness about climate responsive and energy efficient buildings various passive strategies - like apt orientation, placement and size of windows and optimum use of daylight – are being used. Reduction of energy consumption in conjunction with thermal comfort, health and safety of the occupants thus, helps in achieving energy efficiency. Primary elements of the building envelop affecting the performance of the building are roof, walls, openings and shading devices. All the heat gains or losses from the inside to outside are through this envelop only. Today, these are just designed as elevations, cosmetic in nature and not actively designed in response to climate. It is necessary that this huge mass of the building envelop is given a thoughtful design approach to make the building more energy efficient. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 2
  3. 3. ‘Design with Sun’ – A solution for envelope Design This research aims to put forward how passively designed envelopes with an architectural language developed in response to climate can be active in reducing energy consumption and providing visual and thermal comfort rather than just being mere skins analysing with the help of simulation tool for an office building. The rules of architectural grammar thus, can be set in response to climate and every architect can with the use of this design vocabulary evolve a healthy designed building envelop for an office building. Today the architect can no longer control every detail in its technical entirety – the range of technological developments and product diversity has become too broad. This book will provide an overview of typical solutions, the underlying systems as well as their functionalities. This information will allow the architect to be a competent partner in envelope design. It will enable him or her to understand the suitability of each system in a specific part of the design and to determine its technical and geometrical limits. Starting point of this should be somewhere in India from where it may grow and can be applied to other cities, so I have taken Aurangabad city which is centre point of Maharashtra with booming real estate development. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 3
  4. 4. ‘Design with Sun’ – A solution for envelope Design ACKNOWLEDGMENT In fact it took a lot of people’s help to complete this thesis and I am immensely indebted to each and everyone. I Sought help from the people listed below. They gave it freely and cheerfully. I therefore take this opportunity to thank and appreciate their generosity. I owe my sincere thanks to my external guide Ar. Hemant Mahajan for his regular guidance, valuable suggestions for developing the methodology of research. His wide knowledge helped me a lot in analysis and decision making. His devotion and time inputs from his busy professional commitments have added great value to the study. I would like to express my sincere and heartfelt thanks to my guide Ar. Namarata Dhamankar whose constant, impartial guidance and inspiration and encouragement push me to complete my thesis. I would like to thank the HOD Prof. Poorva Keskar. Her understanding, knowledge vision towards the subject provided conceptual base for this subject. I thank to our thesis co-ordinator Ar. Anshul Gujrathi, her constant encouragement to arrive at a worth full solutions. And to the remaining staff members of the Department, who were all kind enough to help me in my needs. I thank all my jury members who directed me in my subsequent juries. Their suggestions have been of great value in the study. I would like to thank our principal Dr. Anurag Kashyap for providing basic infrastructure and facilities in college itself. I even express my sincere thanks to the library staff for their cooperation in providing respective study books at times. I thank my fellow classmates and friends too for their warmth and support, their love and the pleasure of their company specially Ms. Anupama Chetty whose moral support and love made me to complete this thesis. I feel very lucky to have such loving and caring roommates Ms. Nidhi Dixit and Ms. Dimple Shah, their support and sharing everything with them made me relax and made me back on track really thanks to them. Sincere and special thanks to my parents, sister and brother for their love, support, blessings and above all for believing in me always more that I did and showing me a beautiful future. Last but not the least I thank the Almighty God for showing me the way and always being with me. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 4
  6. 6. ‘Design with Sun’ – A solution for envelope Design 1. INTRODUCTION 1.1 Solar energy 11 1.2 Need of Energy for building 13 1.3 Need of solar Consideration 14 1.4 Global scenario for Solar consideration 16 1.5 Solar considerations in India. 19 1.6 Why Aurangabad city? 22 1.7 Why an Office building? 23 1.8 Aim, Objectives and scope 25 2. LITERATURE REVIEW 2.1 Building Envelope 28 2.2 Solar energy and building 29 2.3 Heat form of solar energy 30 2.4 Light form of solar energy 33 2.4.1 Daylight 33 2.4.2 Solar PV (Active means) 35 3. CLIMATE DATA FOR AURANGABAD 3.1 About Aurangabad 39 3.2 Climatic parameters 41 3.3 Implication of climate on building design SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 6
  7. 7. ‘Design with Sun’ – A solution for envelope Design 4 DESIGN CONSIDERATIONS 4.1 Design Checklist 48 4.2 Sun Path diagram 52 4.3 Orientation of buildings 57 4.4 Building Envelope 58 4.5 Different strategies for Daylight 62 4.6 Different strategies for Thermal comfort 67 4.7 Active strategies 68 4.8 Office building Layout 69 5. BUILDING MATERIAL 5.1 Material consideration 73 6. RELATED STANDARDS 6.1 Related standards 77 7. WHY SIMULATION? 7.1 Why simulation 81 8. HANDBOOK 8.1 Case study Analysis 84 8.2 Design Handbook 84 9. FIXED PARAMETER? 9.1 Fixed Parameters 85 9.2 Parameters to analyse 86 SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 7
  8. 8. ‘Design with Sun’ – A solution for envelope Design LIST OF FIGURES Fig 1. Solar energy on Earth Fig-2. World Map showing Location of India in tropic zone Fig 3. Solar Map of India Fig 4. Energy Consumption Pattern in Buildings Fig.5 Vastu Purush Fig.6 Climatic Parameters affecting Building Fig.7 Solar radiation and building Fig 8. Egyptian city Fig 9. Street Pattern of Harappa Fig 10. Plan of Greek city - as example of ideal solar city Fig 11. Baths in Roman keeping public cool in summer and providing protection in winter Fig 12. Heavenly light in Christian Architecture Fig 13. Islamic Architecture Fig 14. Crystal Palace Fig 15. US downtown office Fig 16. Climate zone of India Fig 17. Diffrent climatic zones in India Fig 18. Envelope design of Jaisalmer Fig 19. Envelope design of Kerala Fig 20. Envelope design of Bangalore Fig 21. Envelope design of Shimla Fig 22. Envelope design of Leh Fig 23.Envelope design of Birbals house, Fathepur sikhri Fig 24. Table shows intensity for considerations of climatic parameters for different climate zone of India Fig.25 Climate zone map of Maharashtra Fig. 26 Map of Maharashtra Fig 27 Changing trends of Office buildings Fig 28. Infosys, Pune SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 8
  9. 9. ‘Design with Sun’ – A solution for envelope Design Fig 29. Two forms of solar energy Fig 30.Solar radiation, convection and conduction Fig 31 Thermal balance of building Fig 32. Heat transfer processes occurring in wall Fig 33 Source – Monthly temperature graph Fig 34 Graph showing Aurangabad’s weekly relative humidity for a Year Fig 35 Graph showing Aurangabad’s weekly average cloud cover for a Year Fig 36 Graph showing Aurangabad’s weekly average direct solar radiation for a Year Fig 37 Graph showing Aurangabad’s weekly average diffuse solar radiation for a Year Fig 38 Annual wind frequency showing prevailing wind direction for Aurangabad city Fig 40 Mean monthly maximum and minimum Psychometric chart Fig 41. Psychometric chart with different design techniques Fig 42. Sun Path Diagram for Aurangabad city fig 43. Vertical Shading Angles (Refer Appendix B) Fig 44. Horizontal Shading Angles (Refer Appendix B) Fig 45. Vertical and horizontal shading devices Fig 46. Orientation for daylight Fig 47 Thermal chimney Fig 48. Shading by vegetation and the use of light-coloured surfaces to reduce solar gains to the envelope SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 9
  10. 10. ‘Design with Sun’ – A solution for envelope Design Chapter -1 Introduction 1.1 Solar energy 11 1.1.1 Solar energy on earth 1.1.2 Solar energy for Indian Climate 1.2 Need of Energy for building 13 1.2.1 In Indian Context 1.3 Need of solar Consideration 14 1.4 Global scenario for Solar consideration 16 1.4.1 The city as accumulator of solar derived resources 1.4.2 Spectacular Architecture 1.4.3 Architecture for an Industrial age 1.5 Solar considerations in India. 19 1.5.1 Hot and dry Climate 1.5.2 Warm and Humid 1.5.3 Moderate 1.5.4 Cold and Cloudy 1.5.5 Cold and Sunny 1.5.6 Composite 1.6 Why Aurangabad city? 22 1.7 Why an Office building? 23 1.8 Aim, Objectives and scope 25 SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 10
  11. 11. ‘Design with Sun’ – A solution for envelope Design 1.1 SOLAR ENERGY Earth was formed 4 billion years ago. And human existence came into being before 200 thousand years ago. But no one knows when Sun was formed and for how much year it is going to last. Sunlight is Earths primary and most readily available source of energy. The light from the Sun heats our planet and makes life possible. Light from the Sun also drives Climate and Weather of our planet. The sunlight, water and the plants work together to supply the energy for us. From showering in the morning till sleeping at night, many of the activities that we engage in need different types of energy. In developing practices this energy generation consumes lot of natural resources. Large quantities of non renewable fossil fuel used to generate this energy. But continues use of this energy and its different application is causing us in different forms like natural disasters, lack of resources etc. it is causing to our ecology and environment, and most importantly this is also going to affect our future. This is high time, therefore to finally adopt a new philosophy and to embark on the road towards sustainable development based on renewable energy resources. These renewable energy resources are Sun, Wind, Water, Biomass and Waste matter etc. In which Sun is largest source of energy. As it is difficult to change our wasteful lifestyle and decrease energy consumption the only possible solution will be to handled our resources carefully and to study how efficiently we can use them. 1.1.1 Solar Energy on Earth In incident radiation of Sun on the earth alone is 3000 times greater than the worldwide demands. 1 Where does all this energy go? About 15 percent of the sun’s energy which hits the earth is reflected back to space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produces rainfall. Solar energy is also absorbed by plants, the land, and the oceans. The remaining could be used to supply our energy needs. 15% Reflected back to space 30% Evaporate Water which produces rainfall Some percentage’s absorbed by Plants, land and oceans. Where does remaining go? Fig-1, Solar energy on Earth 1 Solar Architecture by - Christian Schittich. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 11
  12. 12. ‘Design with Sun’ – A solution for envelope Design 1.1.2 Solar Energy for Indian Climate Fig-2. World Map showing Location of India in tropic zone As Earth rotates on its tilted axis around the sun, Sun rays hit the earths surface at different angles. Depends on the direct and lesser angles different parts of the Earth receive higher and lower levels of radiant energy which tend to be hotter and cooler regions respectively and this also tend to create the seasons.2 The suns rays hit the equator at a direct angle between 23 ° N and 23 ° S latitude. Radiation that reaches the atmosphere here is at its most intense. In all other cases, the rays arrive at an angle to the surface and are less intense. The closer a place is to the poles, the smaller the angle and therefore the less intense the radiation. Favourable location of India in tropical zone, works as an advantage to tap different non – conventional source – with Sun as abundant source. As India lies in sunny regions of the world, most parts of India receive 4-7 kWh of solar radiation per square metre per day with 250-300 sunny days in a year. India has abundant Solar resources, as it receives about 3000 hours of sunshine every year, equivalent to over 5,000 trillion kWh. India can easily utilize the solar energy or Solar Power.3 Fig 3. Solar Map of India As a result of the efforts made during the past quarter century, a number of devices have been developed and have become commercially viable to harness the Sun. These include Solar Cookers, Solar Lanterns, Solar Street Lights, and now a day’s Solar P.V’s, Solar Water Heaters, and Solar Water Pumps. 2 3 SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 12
  13. 13. ‘Design with Sun’ – A solution for envelope Design 1.2 NEED OF ENERGY FOR Building The design of a building has a significant impact on energy requirements during the construction and operation phases. The shape of the building, the land area to volume ratio, the orientation of the building, etc, all contribute to energy requirements when the building is occupied. Designers need to assess the environmental impact and economics of different forms and designs of buildings to arrive at the optimal solution. Implementing energy-efficient building technologies and efficient construction techniques can reduce construction wastage for the same built-up area of the structure, compared to conventional designs. In terms of energy consumption, it would lead to reduction in cooling and lighting requirements inside the building. 1.2.1 In Indian Context Buildings account for an estimated 30 percent of the total energy consumption in India.3 Furthermore, the absolute figure is rising fast due to booming real estate demand and increasingly affluent lifestyle across various sections of society. Estimates indicate that globally buildings are responsible for approximately one-third of energy-related CO2 emissions and three-fifth of halocarbon emissions. In addition, the buildings sector offers the largest potential to reduce greenhouse gas (GHG) emissions at relatively lower cost compared to other sectors. Large reductions can be achieved in buildings energy consumption at a net benefit. 4 In India energy consumption load for building is basically only for cooling and lighting. Our role is how we can reduce energy consumption for both. Fig 4. Energy Consumption Pattern in Buildings (India)5 Office buildings consume large amounts of electrical energy for air-conditioning and lighting than residential buildings. 4 Energy Efficiency in Buildings: Indian Market Landscape (Date Published: 4 Nov 2009) By Vivek Gautam, Sr. Research Analyst - South Asia & Middle East, Environmental & Building Technologies Practice, Frost & Sullivan 5 Frost & Sullivan SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 13
  14. 14. ‘Design with Sun’ – A solution for envelope Design 1.3 NEED OF SOLAR CONSIDERATION As an Architect while designing the structure, we need to take considerations for intense radiation coming to earth whilst reducing energy consumption of building. From centuries on with deep study of climatic parameters, people have achieved some considerations. Our Vastu is one of the strongest solution of this study. It is evolved totally on position of Sun at day time; it gives idea where to place which activity in house which will give comfortable conditions at different times of day at that particular space. Fig.5 Vastu Purush Three basic climate parameters which will affect the building, Sun Wind Rain Fig.6 Climatic Parameters affecting Building The building should response to the three basic climate parameters6 to achieve thermal and visual comfort with energy efficiency, Sun, For Thermal comfort: Let the sun’s heat in when it is cold and keep the sun’s heat out when it’s hot. For Visual comfort: Allow natural light during the day time. For energy efficiency: Through use of photovoltaic and help collect heat i.e., solar hot water, and generate electricity. Wind, For Thermal comfort: Natural ventilation in summer, controlled minimum ventilation in winter. For energy efficiency: Generate electricity. Rain, The façade needs to be weather tight to avoid rain water in and materials chosen should not be soaking. Excess moisture may cause potential rot and fungal growth but humidity of 45% to 60% is necessary for human comfort. Strategies to increase humidity like evaporative cooling may work in hot-dry climates while it needs to be reduced in places where it is more humid. 6 SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 14
  15. 15. ‘Design with Sun’ – A solution for envelope Design But, Sun is the major parameter which is going to affect the building envelope and which will have an effect on the visual and thermal comfort inside the building. Fig.7 Solar radiation and building SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 15
  16. 16. ‘Design with Sun’ – A solution for envelope Design 1.4 GLOBAL SCENARIO FOR SOLAR CONSIDERATION Architecture is that great living creative spirit which from generation to generation, from age to age, proceeds, persists, creates, according to the nature of man, and his circumstances as they change. Frank Lloyd Wright. 1.4.1 The city as accumulator of solar derived resources7 Reason for development of early cities were farming and trade but “ un, wind and water were the “Sun, guiding principles.” The river valleys of the Tigris and Euphates (Mesopotania), Nile (Egypt), Indus (India) and Wei-Huang (China) provided ideal conditions for the early Huang civilizations to establish cities. In Mesopotania, the need to collaborate in building and maintaining irrigation systems provided a catalyst for the creation of solar energy to food energy, but also in time were incorporated into the city structures themselves. Fig 8. Egyptian city Babylon also clearly illustrated the importance of sun orientation in its city rated form. The streets were arranged so that they enabled residents to derive the benefits of the climate such as light, warmth and favorable breezes. Kahun as an example we can say that it was solution for p protection against harsher elements in the ancient Egyptian city. Indus valley supported large settlements example was Harappa and Mohenjo-Daro. They were constructed to a high density bored upon a grid like structure, with the street pattern taking its orientation from the sun. Similar processes of city formation began to take place in the Wei-Huang Fig 9. Street Pattern of Harappa valley of China and forests of the Mayan civilization in central America between 1000 & 2000 B.C. for Greek and Roman cities the grid was aligned according to solar orientation to maximize the benefits of this direct energy source, as well as minimize the benefits of this direct energy source as well l as minimize its detrimental effects by providing ventilation and shade. Based on the principles of solar orientation and ventilation ancient Greek cities represented the ideal solar city for a true democratic society. Every unit was organized around a courtyard. The building to the north was used for living. The main room had a shaded porch facing south. Fig 10. Plan of Greek city - as example of ideal solar city 7 Book on Solar Power – the evolution of Sustainable Architecture by Sophia and Stefan Behling SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010 2010-11) Page 16
  17. 17. ‘Design with Sun’ – A solution for envelope Design 1.4.2 Spectacular Architecture From Greek antiquity to the industrial revolution: Spectacular architecture was predominant in the secular built environments of the ancient world. Markets forums, amphitheaters, & baths were designed to attract the public to gather and so had to after high levels of environmental comfort, keeping the public cool in summer and providing protection in winter. At the same time, the wealthy found that they were able to surround themselves with Fig 11. Baths in Roman keeping luxury within their private places and villas, creating perfect indoor public cool in summer and climate using passive ventilation, sunlight and solar shading. providing protection in winter In the middle ages, solar energy continued to have a strong influence on Christian architecture, inspiring the orientation of churches and being used to create fantastic effects to give worshippers glimpses of heavenly light. The mosques and palaces of the Islamic world were designed with a concern for solar shading rather than a pure expresser of grandeur. Mughal architecture in India had introduced magnificent palaces that were cooled in summer and heated in winter with the use of understanding of materials used for construction of structures. Fig 12. Heavenly light in Christian Architecture The Renaissance brought the light, openness and solar sophistication of classical architecture to European building. 1.4.3 Architecture for an Industrial age: Fig 13. Islamic Architecture New technologies based upon the use of fossil fuels provided the pivotal factors for industrial revolution. This power source enabled the replacement of small workshops by large, mechanized factories. The new technologies of the industrial revolution enabled architects and builders to transcend the limitation of human scale. Example of crystal palace built for the great exhibition of 1851-represented and inspired pieces of technological engineering rather than feats of architecture. Architecture, urban planning and all other arenas of culture aimed to symbolize Fig 14. Crystal Palace this new age. Some favoured a return to nature and disurbanism while other rejected individuality and romanticism and favoured scientific rationality. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 17
  18. 18. ‘Design with Sun’ – A solution for envelope Design Modern architecture was not simply an expression of a new aesthetic image, but the very substance and representation of the new social condition that were to be created. Notion of less being more and form following function as well as a vision of buildings as machines for living “represented the rationality and objectivity structuring the dominant architectural design at the time. “ Following world war two, a similar dichotomisation of solar living arrangements was apparent on the on hand the construction of high density, modernist blocks surrounded by green open spaces gained favour in both inner city regeneration and peripheral city housing estates. On the other hand, population dispersal and movement to suburbs gathered pace.” In the UK lower densities were encouraged through the new towns programme continuing garden city concept. In the US, the productive capacities and innovative technologies could be redirected into creating new living and working patterns-a spatial downtown areas, glass tower constructions were facilitated by continually improving technologies in lift design and operation heating ventilation and cooling systems, internal restructuring for example, open floor planning and novel architectural and engineering techniques. By improving our living environments through lower density living and our working environments through mechanically controlled office and factory spaces, we have increased our energy consumptions and requirements dramatically. So in the industrial age, technological advances have brought about a Fig 15. US downtown office building continually growing dependency upon both their technologies and energy requirements. Furthermore the two world wars demonstrated the potential to use technology for devastation and dehumanisation of killing through increased mechanisation. America produced an international architectural style for the business community. Businesses turned their back on nature and buildings became completely dependent on huge energy supply. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 18
  19. 19. ‘Design with Sun’ – A solution for envelope Design 1.5 SOLAR CONSIDERATIONS IN INDIA. Depends on Sun radiation intensity and Sun’s position different climatic zone has different architectural style. Lot of architects have understood it and implemented it in their designs and they have been successful to attain solar considerations for building which helped them to achieve comfort inside the building. Climatic zone - Regions having similar characteristic features of climate are grouped under one climatic zone. India possesses a large variety of climates ranging from extremely hot desert regions to high altitude locations with severely cold conditions. The six distinct climates of India are, Hot and Dry, Warm and Humid, Moderate, Cold and Cloudy Cold and Sunny, Composite. We can differentiate these zones on the basis of following table,8 Fig 16. Climate zone of India Different climatic zones of India Mean monthly Climate Relative humidity (%) temperature (0C) Hot and Dry > 30 < 55 Warm and Humid > 30 > 55 Moderate 25-30 < 75 Cold and cloudy < 25 > 55 Cold and Sunny < 25 < 55 This applies when six months or more do not Composite Fig 17 fall within any of the above categories Traditional architecture in India has a different design approach in response to the respective climate; it shows outstanding evidence of how the intelligent use of space, building design and material ensures optimal comfort from climatic parameters inside the building and without any mechanical means. 8 National building code, India (2005) SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 19
  20. 20. ‘Design with Sun’ – A solution for envelope Design 1.5.1 Solar considerations for different climatic zones Hot and Dry climate Example - Jaisalmer Jharoka’s with Jalis or smaller windows are provided to cut the intense solar radiations and filter dust storms with use of local material – sandstone. Flat roofs are provided. In such a climate, it is imperative to control solar radiation and movement of hot winds. The design criteria should therefore aim at resisting heat gain by providing shading, reducing exposed area, controlling and scheduling ventilation, and Fig 18. Envelope design of Jaisalmer increasing thermal capacity. Warm and Humid Example - Kerala Covered verandas are provided for shading the walls and to get cool air inside the building. Attics with protected windows provided to draw in maximum daylight. Arched openings are also used as structural elements at some places. Sloping roofs are provided as consideration for rain. Use of local materials – Brick or stone for wall, Fig 19. Envelope design of Kerala Mangalore clay tiles for the roof. Moderate Example - Bangalore Exposed masonry construction is provided to maintain the comfort of building with protected maximum openings for efficient cross ventilation and maximum daylight. Shading devices or projections are designed to protect from sun and rain. Courts are provided to maintained cross ventilation everywhere in house. Fig 20. Envelope design of Bangalore SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 20
  21. 21. ‘Design with Sun’ – A solution for envelope Design Cold and Cloudy Example - Shimla Attics are provided at tops and roofs are designed to store heat and decipiate to lower spaces, it gives characterize appearance to the building envelope. Maximum glass openings are provided to get the heat. Thick stone walls are constructed for thermal mass (to store the heat), wood also used for construction. Fig 21. Envelope design of Shimla Cold and Sunny Example - Leh Generally building plans are slightly trapezoidal, heavy at the bottom with stone foundations and light at the top, generally with battered walls. The walls are thick and the mud is mixed with hay to provide insulation. It helps to insulate and create a heat storage space for the winter months. Cold climate in India has variations at various locations in terms of sky clearance. Hence, examples peculiar to each of these sub-zones are illustrated. Fig 22. Envelope design of Leh Composite Example – Fathepur sikhri Less openings are provided on southern façade, and long eaves with carved brackets to shade the facades. Smaller windows are given to avoid heat coming inside the building. Walls are thick constructed with local stones. Intencity for considerations of Climatic paramters Fig 23.Envelope design of Climatic zones Sun Wind Rain Birbals house, Fathepur sikhri Hot and Dry climate Warm and Humid Moderate Cold and cloudy Cold and Sunny Composite Fig 24. Table shows intensity for considerations of climatic parameters for different climate zone of India SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 21
  22. 22. ‘Design with Sun’ – A solution for envelope Design 1.6 WHY AN AURANGABAD? Aurangabad comes under hot and dry climate zone in India. India is developing like shoot in the world. The needs of Metropolitan cities are increasing day by day, large amount of people are migrating towards cities for employment and because of standard of living. With increase in employment generation commercial and industrial constructions are growing giving opportunities for Aurangabad Architect to prove themselves. Because of globalization new construction techniques have been adopted by the architects and because of changed construction style commercial buildings are increasing loads of electricity consumptions for lighting and cooling. Realizing the fact lot of construction industry and architects are taking considerations but number should increase and there is requirement of proper design strategies with respect to consideration for climate parameters and increasing use of renewable resources. Studying above intensity of considerations for climatic parametrs I have taken Aurangabad Which comes under hot and dry climate zone in India. Moreover in developing cities like Aurangabad there is a lot of scope to implement the strategies as they can be applied right from first stage of construction with proper building performance analysis. And which can be applied to other areas of state. Aurangabad Fig.25 Climate zone map of Maharashtra Fig. 26 Map of Maharashtra SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 22
  23. 23. ‘Design with Sun’ – A solution for envelope Design 1.7 WHY AN OFFICE BUILDIN ? BUILDING Earlier around 20 years ago the only machines found in the Indian offices were mechanical typewriters and duplications. These gave way to electric type writers, photocopying machines and telex machines but there was a revolutionary change in the advent of personal computers around the year 1985. Those machines have not only increased productivity but are able to perform certain e innovative functions, making tasks easier thus enabling the organizations to expand their operations. It can be seen that the new constructions are done in such a way that the envelope looks beautiful whatever may be the situation inside and forgetting totally that the structure is a part of Fig 27 Changing trends of Office buildings environment. This all leads to the loads of energy consumption and it is affecting the visual and thermal comfort of a person inside the building. The office buildings consume energy for lighting air-conditioning and lighting, conditioning ventilation resulting in the major operational costs. As offices function mainly during the daytime the use of naturally available light must b optimum be decreasing usage of artificial light. There is a need to apply certain strategies right from the initial stage of designing a complex as this can reduce the stress on the environment in its future operational stage and also helps to achieve thermal and visual comfort inside the building which will thermal increase human efficiency and avoid ill health effects effects. Commercial buildings use air-conditioning mechanical means for providing thermally comfortable conditioning indoor conditions. This is mainly aimed at promoting productivity among occupants. However, the process is energy intensive and the running costs are generally very high. The monthly electricity bills of a typical commercial building can run into lakhs of rupees. The options for energy conservation are limited once a building is constructed, especially when aspects of optimal energy use have not been taken into account in building design. Considering that many such buildings are being constructed all over India, there is an urgent need to study their thermal behaviour and their explore various means to reduce the AC load. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010 2010-11) Page 23
  24. 24. ‘Design with Sun’ – A solution for envelope Design The evaluation of strategies during the early days or the design intent phase of a project provides the best opportunity to take a broad perspective, from a building as a whole structure rather than individual components. With this approach, design teams are able to evaluate key initial decisions such as the size of the building footprint, the composition of the building envelope, or the building orientation that will affect subsequent decisions. Example The Infosys building, Pune, due to its form is one of the architectural marvels in India. But the user faces discomfort due to the manner in which the openings or the glazing are placed. It causes glare and overheating into the building which leads to dependency on mechanical cooling systems for comfort. Thus, the envelope just serves as a cover but Fig 28. Infosys, Pune instead of protecting and makes internal conditions uncomfortable. If these issues were addressed taking into considering the sun path diagram and the radiations falling over the surface, the building envelop would have been more efficiently designed and evolved as a sustainable design solution. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 24
  25. 25. ‘Design with Sun’ – A solution for envelope Design HYPOTHESIS Designing with Sun for building envelope can help to make physically as well as visually comfortable building there by generating energy for building. AIM Aim of this dissertation is to list out the design consideration for harnessing the Sun through building envelope for an office building in Aurangabad city to get efficient and sensible design which will help to increase the human efficiency at workplace; e This will be with giving consideration for controlled solar shading systems that enable the building to iving react to the sun’s position so as to optimise the flows of heat and light energy through the envelope, and which will help for reducing the heat load, glare and enhances the use of natural daylight thereby reducing the operating costs of the building. OBJECTIVE So objectives are to study considerations for, Sun protection and solar control Excellent daylighting quality Passive gain from solar energy Architecture appeal Solar power generation lar SCOPE Design considerations will be developed considering requirements of only an office building for the city of Aurangabad. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010 2010-11) Page 25
  26. 26. ‘Design with Sun’ – A solution for envelope Design METHODOLOGY Selection of thesis topic Literature Study Various aspects related to the topic Climate data of Aurangabad Consideration for thermal and visual comfort Study of related standards Case study Observations Analysis with simulation Analysis Modelling and Parametric Study of considered Office Segment with help of Ecotect simulation software Findings Generalizing the result-inferences Preparation of considerations which we can apply in future for upcoming office building SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 26
  27. 27. ‘Design with Sun’ – A solution for envelope Design Chapter -2 LITERATURE REVIEW 2.5 Building Envelope 28 2.6 Solar energy and building 29 2.2.1 forms of solar energy 2.7 Heat form of solar energy 30 2.3.1 Type of solar gain to the building 2.3.2 Forms of heat gain 2.3.3 Heat loads 2.8 Light form of solar energy 33 2.4.1 Daylight 33 Daylighting Daylighting for office building 2.4.2 Solar PV (Active means) 35 Solar Photovoltaic’s Architectural Application SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 27
  28. 28. ‘Design with Sun’ – A solution for envelope Design 2.1 Building Envelope Strategies for energy efficiency and thermal comfort of a building have to be incorporated at the design stage. One of these could be passively designed envelops which actively meet the heating and cooling needs of the building. Building envelopes not only provide the thermal divide between the indoor and outdoor environment, but also play an important role in determining how effectively the building can utilise natural lighting. Thus, intelligent configuration and moulding of the built form . and its surroundings can considerably minimise the level of discomfort inside a building, and reduce dings the consumption of energy required to maintain comfortable conditions. As seen before traditional architecture developed envelopes which responded to internal demands raditional combined with external conditions9 and h hence, the envelope developed had their own characters conducive to the respective climate and local materials. Today due to globalization and technological advancement, architectural flexibility has grown with no restrictions to location or climate. The approach is being in the trend and thus, if due to the ictions building envelope the internal comfort is not met; mechanical systems are well available at our disposal. Hence, the challenge today is to design envelope which integrate and apply new technologies with respect to ancient wisdom to innovatively incorporate passive strategies when designing facades and still being in the race for modern contemporary architectural style. A building interacts with the environment through its external façades such as walls, windows, environment projections, and roofs, referred to as the building envelope. The envelope acts as a thermal shell, which if thoughtlessly constructed, would result in energy leaks through every component. Hence, each component needs to be properly chosen to ensure an energy efficient building. ch The nature of a building envelope determines the amount of radiation that will enter the building. It consists of the following elements: Roof Walls Fenestrations External colour and texture Roof Walls Fenestration External colour and textures 9 SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010 2010-11) Page 28
  29. 29. ‘Design with Sun’ – A solution for envelope Design 2.2 SOLAR ENERGY AND BUILDING SUN LIGHTING IS FORMGIVER FOR ARCHITECTURE BY – William M.C.Lan (1902) Process of architectural design is a complex exercise, involving interactive relationships between parameters of diverse nature & varying magnitude. Various ideas have dominated architectural thoughts for centuries, yet the fundamental issue of energy as an embodiment of Sun, Wind, and Light has lost from the design which has been resulted into vast consumption of natural resources. So, architectural design must respond to ecological context, the logical approach based on quantitative assessment leading to qualitative design decisions. Building envelope is affected by three climate parameters Sun, Wind and Rain. But Sun is major factor which will affect the building envelope whilst affecting inside visual and thermal comfort of a building. 2.2.1 Forms of Solar energy Solar energy affects the building in two forms, Heat form Light form Heat form Light form Fig 29 two forms of solar energy Heat form of solar radiation occurs predominantly through the roof and windows but also through walls. Thermal radiation moves from a warmer surface to a cooler one. With controlled light form of solar radiation inside the building we can achieve day lit spaces with required visual comfort of a person. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 29
  30. 30. ‘Design with Sun’ – A solution for envelope Design 2.3 HEAT FORM OF SOLAR ENERGY When we consider Building as unit and Sun as a source of light Solar energy may exchange in form of heat from out-door environment to indoor environment. 2.3.1 Types of Solar gain to the building There are five primary passive solar energy configurations, Direct solar gain Indirect solar gain Isolated solar gain Heat storage Insulation Direct gain attempts to control the amount of direct solar radiation reaching the living space. Indirect solar gain - Heat enters the building through windows and is captured and stored in walls and slowly transmitted indirectly to the building through conduction and convection. Isolated gain involves utilizing solar energy to passively move heat from or to the living space using a fluid, such as water or air by natural convection or forced convection. Examples are sunspace, solarium or solar closet and solar chimneys. The sun doesnt shine all the time. Heat storage or thermal mass keeps the building warm when the sun cant heat it. This included a Trombe wall, a ventilated concrete floor, or roof pond. Thermal insulation reduces unwanted leakage of heat and also it prevents unwanted heat coming inside the building. 2.3.2 Forms of heat gain Heat transfer in buildings occurs through convection, conduction, and thermal radiation through roof, walls, floor and windows. Natural convection causing rising warm air and falling cooler air can result in an uneven stratification of heat, this may cause uncomfortable variations in temperature which will affect the thermal comfort of person. Strategic placement of operable windows or vents can enhance convection. Radiation is the heat transfer from a body by virtue of its temperature; it increases as temperature of the body increases. It does not require any material medium for propagation. Fig 30.Solar radiation, convection and conduction. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 30
  31. 31. ‘Design with Sun’ – A solution for envelope Design 2.3.3 Heat loads For an office building the accurate calculation of heating and cooling loads is essential to provide a sound bridge between fundamental building design decisions and an operating building. Occupants and users will likely be hot or cold, if loads are substantially overestimated; equipment will be oversized avoiding wasting money, reducing efficiency, increasing energy consumption, and often hazardous comfort. Accurate heat load calculations are an important part of the design process. Sensible and latent loads Heat gain through building envelope Heat gain through windows and skylights Internal heat gains Outdoor air flow Loads are sensible (affecting air temperature) or latent (affecting relative humidity) or a combination of sensible and latent. Sensible and latent heating and cooling loads arise from heat transfer through the opaque building envelope; solar heat gain through windows and skylights; infiltration through openings in the building envelope; internal heat gains due to lighting, people, and equipment in the conditioned spaces; and outdoor airflow form ventilation and building pressurization. The thermal balance i.e. the existing thermal condition is maintained if,10 Qi + Qs + Qc + Qv + Qm – Qe = 0 If Sum of this equation is less than zero (negative), the building will be cooling and if it is more than zero, the temperature in the building will increase. Fig 31 Thermal balance of building 10 Manual of tropical housing and building by O.H. Koenigsberger SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 31
  32. 32. ‘Design with Sun’ – A solution for envelope Design Qc - Conduction of heat may occur through the walls either inwards or outwards, the rate of which will be denoted as Qc. Qs - The effects of solar radiation on opaque surfaces can be included in the above by using the sol-air temperature concept, but through transparent surfaces (windows) the solar heat gain must be considered separately. Qv.- Heat exchange in either direction may take place with the movement of air, i.e. ventilation and the rate of this will be denoted as Qv. Qi - An internal gain may result from the heat output of human bodies, lamps, motors and appliances. This may be denoted as Qi Qm. - There may be a deliberate introduction or removal of heat (heating or cooling), using some form of outside energy supply. The heat flow rate of such mechanical controls may be denoted as Qm. Qe. - If evaporation takes place on the surface of the building or within the building and the vapours are removed, this will produce a cooling effect, the rate of which will be denoted as Qe. As an architect, while designing the building envelope with respect to the Sun energy we need to take care for heat through envelope, windows and skylights. Our aim should be to minimise the conduction through walls, windows, skylights and through roofs with proper design strategies like orientation of building with study of sun path, controlled shading devices which will avoid the direct solar radiations on facade, and with strategies for roof and materials should be study with high Fig 32. Heat transfer processes resistance and low U value. occurring in wall The heat gain through each element can be varied by: area of the element orientation and tilt of the element material properties (U-value, time lag, decrement factor, transmissivity, emmissivity, etc) finishes control of incoming solar radiation SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 32
  33. 33. ‘Design with Sun’ – A solution for envelope Design 2.4 LIGHT FORM OF SOLAR ENERGY Architecture is that great living creative spirit which from generation to generation, from age to age, proceeds, persists, creates, according to the nature of man, and his circumstances as they change. - Frank Lloyd Wright. 2.4.1 Daylight (Passive means) Architectural forms, textures, materials, modulation of light and shade, colour all combine to inject a quality of spirit that articulates space. The quality of architecture will be determined by the skill of the designer in using and relating these elements, both in interior spaces and spaces around the buildings. Daylight has always been of major importance like temple design with clearstories for light, cathedral design with glass windows and some commercial spaces, but somehow in 1960’s, we forgot everything we knew about the art and science of daylight. Cheap energy and air conditioning did us in. "Light is not only an amount of energy, it also provides us with the means to reveal spaces and volumes and interact with our environment." - Mr. Andersen,from Building Technology Program. Daylighting Most simply, day lighting is the practice of using natural light to illuminate building spaces. Rather than relying solely on electric lighting during the day, day lighting brings indirect natural light into the building. Daylighting helps create a visually stimulating and productive environment for building occupants, while reducing as much as one-third of total building energy costs. The ultimate source of daylight is the Sun, but the light arriving at the earth from the sun may be partly diffused by the atmosphere and the locally prevailing atmospheric conditions determine how this light reaches the building. Climatic conditions greatly influence both quantity of light and the relative magnitude of all the components of daylight. There are three possible ways that daylight can reach the indoor working plane. Visible light directly from the sky vault (define) Light reflected from exterior surfaces. Light entering the space and reflecting from interior surfaces. All three of these components need to be accounted for to determine the daylight factor. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 33
  34. 34. ‘Design with Sun’ – A solution for envelope Design As explained earlier daylighting has the potential to Benefits of Daylighting significantly improve increase user productivity with reducing energy consumption of building which will Increase aesthetic value of space indirectly helps to reduce carbon emissions and reduce operating costs for building. Increase user productivity Daylight adds sense of speciousness to a room. Reduce energy consumption Daylight is crucial for the natural biorhythm of man. Whether used as a straightforward source of illumination or Reduce carbon emissions modified by judicious effects to arouse the emotions, light is a phenomenon that influences the behavior of people. Reduce operating costs Daylighting for office building A review of peoples’ reactions to indoor environments suggests that daylight is desired because it fulfils two very basic human requirements: to be able to see both a task and the space well, and to experience some environmental inspiration. Working long-term in electric lighting is believed to be deleterious to health; working by daylight is believed to result in less stress and discomfort. All office buildings are provided with windows at least to the minimum extent laid down in the byelaws. Just providing a weather shed commonly provided over the window openings confirms roughly to the requirement of Sun shading on the south facing windows but such windows do not distribute daylight evenly. Poorly designed windows and skylights either cause glare or these may not distribute sufficient light, or this causes office users to drow curtains, pull down ventilation blinds or cut out daylight in other ways and switch on artificial lights. Daylighting involves more than just adding windows or skylights to a space. It is the careful balancing of heat gain and loss, glare control, and variations in daylight availability. For effective daylighting design two factors should be consider - To get effective daylighting controlled daylight should be Factors to be consider for provided as deep as possible into a building interior. The effective daylighting human eye can adjust to high levels of luminance as long as it is evenly distributed. In general, light which reaches a task indirectly will provide better lighting quality than light which Evenly distributed light arrives directly from a natural or artificial source. Control of glare An efficient daylighting design is not only to provide illuminance levels sufficient for good visual performance, but also to maintain a comfortable and pleasing atmosphere. Glare, or excessive brightness contrast within the field of view, is an aspect of lighting that can cause discomfort to occupants. The human eye can function quite well over a wide range of luminous environments, but does not function well if extreme levels of brightness are present in the same field of view. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 34
  35. 35. ‘Design with Sun’ – A solution for envelope Design 2.4.2 Solar PV (Active means) Solar energy, experienced by us as heat and light, can be used through two routes: The thermal route uses the heat for water heating, cooking, drying and other applications; The photovoltaic route converts the light in solar energy into electricity, which can then be used for a number of purposes such as lighting, pumping, and communications. Solar Photovoltaic’s (PV) is a method of generating electrical power by converting solar radiation into direct current e electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels comprised of a number of cells called as solar cells containing a photovoltaic material like silicon. The photovoltaic effect refers t photons of to light knocking electrons into a higher state of energy to create electricity. PV technology is simple and does not need any complex machinery and has no moving parts. It does not use fossil fuel, or needs power stations or electricity pylons o distributed network. or It is silent, unobtrusive and needs less maintenance. As an architect, we don’t need to study its techniques and mechanics but we need to study how mechanics, much space it required and where can we provide space for it? So basically we need to study space requirement to install it. Photovoltaic cells (PV cells) PV cells are the basic building blocks of PV modules that convert the solar energy directly into usable energy by the photovoltaic effect. Approximately 1/2 V is generated by each silicon PV cell. The amount of current produced is directly proportional to the cell’s size, conversion efficiency, and the intensity of light. Assemblies of cells are used to make solar modules, solar panels, or photovoltaic arrays. hotovoltaic As shown in the adjacent figure, groups of 36 series connected PV cells are packaged together into standard modules that provide a nominal 12 volt (0r 18 volts @ peak power). When modules are fixed together in a single mount they are ca called a panel and when two or more panels are used together, they are called an array. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010 2010-11) Page 35
  36. 36. ‘Design with Sun’ – A solution for envelope Design PV cell conversion efficiency PV cell conversion efficiency is calculated as the amount of energy produced by a sqm of cell exposed at 25°C to a standard solar radiation, falling on a square meter of the Earths surface at the equator at noon on a clear day. Conveniently, this is 1000 W, thus a sqm of cell with a conversion efficiency of 15% will produce 150W of peak power. The wattage output of a PV module is rated in terms of peak watt (Wp) units. The peak watt output power from a module is defined as the maximum power output that the module could deliver under standard test conditions (STC). The STC conditions used in a laboratory are 1000 watts per square metre solar radiation intensity. Air-mass 1.5 reference spectral distributions. 25 °C ambient temperature. Architectural application Photovoltaic (PV) modules can be designed as aesthetically integrated building components and as entire structures. Photovoltaic (PV) cells can be integrated into elegant facades without being an eye sore. Building-integrated photovoltaic (BIPV) is sometimes the optimal method of installing renewable energy systems in urban, built-up areas where undeveloped land is both scarce and expensive. BIPV electric power systems not only produce electricity, they also are a part of the building. For example, a BIPV skylight is an integral component of the building envelope as well as a solar electric energy system that generates electricity for the building. These solar systems are thus multifunctional construction materials. The standard element of a BIPV system is the PV module. Individual solar cells are interconnected and encapsulated on various materials to form a module. Modules are strung together in an electrical series with cables and wires to form a PV array. Direct or diffuse light (usually sunlight) shining on the solar cells induces the photovoltaic effect, generating unregulated DC electric power. This DC power can be used, stored in a battery system, or fed into an inverter that transforms and synchronizes the power into AC electricity. The electricity can be used in the building or exported to a utility company through a grid interconnection. A wide variety of BIPV systems are available in todays markets. Most of them can be grouped into two main categories: facade systems and roofing systems. Facade systems include curtain wall products, spandrel panels, and glazings. Roofing systems include tiles, shingles, standing seam products, and skylights. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 36
  37. 37. ‘Design with Sun’ – A solution for envelope Design The fundamental step in any BIPV application is to maximize energy efficiency within the buildings energy demand or load. Holistically designed BIPV systems will reduce a buildings energy demand from the electric utility grid while generating electricity on site and performing as the weathering skin of the building. Windows, skylights, and facade shelves can be designed to increase daylighting opportunities in interior spaces whilst reducing unwanted glare and can provide with required R-value to diminish undesired thermal transference or heat gain. ADVANTAGES The major advantages of using Photovoltaic (PV) systems are as follows. Abundant solar radiation is available in most parts of India. Hence, photovoltaic systems can be used anywhere in the country. PV systems are modular in nature. Hence, they can be expanded as desired and used for small and large applications. Solar electric generation is economically superior where grid connection or fuel transport is difficult, costly or impossible. Grid-connected solar electricity can be used locally thus reducing transmission/distribution losses. There are no running costs associated with PV systems, as solar radiation is free. Electricity is generated by solar cells without noise. PV systems have no moving parts. Hence, they suffer no wear and tear. As most of the components of PV systems are pre-fabricated, these systems can be installed quickly. Hence, PV projects have short development periods. LIMITATIONS Photovoltaics are costly to install. Longer pay back periods. Solar electricity is not available at night and is less available in cloudy weather conditions from conventional photovoltaic technologies. Therefore, a storage or complementary power system is required. Solar cells produce DC which must be converted to AC using a grid tie inverter when used in current existing distribution grids. This incurs an energy loss of 4-12%. Output from PV arrays decline with time. Silicon based cells can be contaminated by iron and oxygen from the atmosphere; materials used for encapsulation can be affected by heat, moisture and UV rays. EXAMPLE 30 kWp Building Integrated Photovoltaic (BIPV) systems are provided at the Samudra Institute of Maritime Studies at Lonavala which is largest BIPV project in India. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 37
  38. 38. ‘Design with Sun’ – A solution for envelope Design Chapter -3 CLIMATE DATA FOR AURANGABAD 3.1 About Aurangabad 39 3.1.1 Location of Aurangabad 3.1.2 Topography 3.1.3 Climate zone of Aurangabad 3.1.4 Climatic seasons 3.2 Climatic parameters 41 3.2.1 Air temperature 3.2.2 Humidity 3.23 Sky conditions 3.2.4 Solar radiation 3.2.5 Wind 3.3 Implications of climate on building design 46 3.3.1 Psychometric chart SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 38
  39. 39. ‘Design with Sun’ – A solution for envelope Design 3.1 ABOUT AURANGABAD Aurangabad city is undisputed fast developed city in Asia with a rich heritage and favourable climate. Aurangabad is named after the Mughal Emperor Aurangzeb. The city is a tourist hub, surrounded with many historical monuments, including the Ajanta Caves and Ellora Caves, which are UNESCO Ellora World Heritage sites. Recently Aurangabad has been declared as Tourism Capital of Maharashtra. 3.1.1 Location of Aurangabad The co-ordinates for Aurangabad are N 19° 53 47" - E 75° 23 54". ordinates Latitude - 19° 53 47" North Longitude - 75° 23 54" East Location of Maharashtra showing Maharashtra showing Maharashtra in India Marathwada region Aurangabad city Aurangabad city is situated in India state of Maharashtra in Marathwada region, at an altitude of , 11 approximately 663 meters above the sea level. 3.1.2 Topography of Aurangabad Aurangabad city is surrounded by the hilly ranges from north, south and west sides. Northern side Municipal limits are flanked by Jathwada hill ranges and on south locally named Satara hills are located. General topography of the city is undulating. Attitude of the city increases towards north side. 11 City development plan for Aurangabad SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010 2010-11) Page 39
  40. 40. ‘Design with Sun’ – A solution for envelope Design 3.1.3 Climate zone of Aurangabad As shown in map Aurangabad city is located in HOT AND DRY climate zone of India. Key features for Hot and Dry - High day temperature and low night temperature. - Low humidity and low precipitation. - Distinct seasonal variations between hot summers and cool Aurangabad winters. - Little air movement. - Sand and dust storms. Climate zones of India 3.1.4 Climatic Seasons of Aurangabad The city experiences favourable climate where neither the summers are extremely hot nor the winters are freezing cold. There is no too big difference between the summer and winter temperatures of the city. The climate of this district is characterised by a hot summer and general dryness throughout the year except during the southwest monsoon season. The year may be divided into four Four Seasons seasons. The cold season from December to February is followed Cold Season December to February by the hot season from March to May. The period from June to Hot Season March to May September constitutes the Southwest monsoon Season June to September southwest monsoon season. October and November form the Post monsoon Season October and November post monsoon season. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 40
  41. 41. ‘Design with Sun’ – A solution for envelope Design 3.2 CLIMATIC PARAMETERS The various climatic parameters that affect human comfort are given below, - Air temperature - Humidity and precipitation - Sky conditions - Solar radiation - Air movement 3.2.1 Air temperature MONTHLY DIURNAL AVERAGES - Aurangabad, IND °C W/ m² 40 1.0k 30 0.8k 20 0.6k 10 0.4k 0 0.2k -10 0.0k Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Above graph shows monthly diurnal averages temperature Fig 33 Source – Autodesk Ecotect range of Aurangabad city. LEGEND In summer the maximum temperature can rise to 40°C while Comfort: Thermal Neutrality the minimum temperature can drop to 15°C. Temperature Rel.Humidity Direct Solar Diffuse Solar In winter the maximum temperature can rise to 30°C and fall Wind Speed Cloud Cover to less than 10°C. And for rainy season maximum points lie in comfort zone and maximum temperature increases to 35°C. Winter Summer Monsoon Post monsoon Months Temp. Jan. Feb. March April May June July August Sep. Oct. Nov. Dec. 0 0 0 0 0 0 0 0 0 0 0 0 Maximum 29 C 30 C 35 C 38 C 39 C 32 C 26 C 27 C 30 C 30 C 27 C 27 C 0 0 0 0 0 0 0 0 0 0 0 0 Minimum 15 C 15 C 20 C 25 C 25 C 23 C 23 C 21 C 22 C 20 C 17 C 13 C Table shows mean daily maximum and minimum temperature for all months May - hottest month of the year. December - coldest month. October - transition period from monsoon to Winter. Critical months for Aurangabad SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 41
  42. 42. ‘Design with Sun’ – A solution for envelope Design From about the beginning of March there is a rapid rise in both day and night temperatures. May is the hottest month of the year with the mean daily maximum temperature at about 400C and mean daily minimum temperature at about 250C. During the hot season the heat is often intense and the day temperatures on individual days may rise above 40oC. With the advance of the southwest monsoon season from mid June there is an appreciable drop in both the day and night temperatures and the weather is pleasant. With the withdrawal of the monsoon by about the end of September the day temperature increases a little and a secondary maximum in day temperature is recorded in October. But night temperatures decreases progressively after the withdrawal of the monsoon. After October both day and night temperatures steadily decrease. The highest maximum temperature ever recorded at Aurangabad was 45.6 0C on 25th May 1905 and the lowest minimum temperature ever recorded was 2.2 0C on 2nd February 1911. 3.2.2 Humidity and precipitation The relative humidity depends as much on the % % 90+ 80 air temperature as on the actual amount of 70 60 100 50 water vapour present in the air. During the day 40 30 20 as the lowest layer of air is being heated by the 10 <0 80 ground surface, its relative humidity is rapidly decreased, whereas at night the situation is 60 reversed.12 40 As shown in graph in summer i.e. March-May 20 relative humidity is low as compare to other Source – Autodesk Ecotect months of the year. It gets increased in 0 Wk monsoon and remains nearly constant for rest 4 8 12 16 20 24 28 32 36 40 44 48 52 Fig 34 Graph showing Aurangabad’s weekly relative humidity for a of the year. Year Except during the southwest monsoon season when the relative Frequency of Annual rainfall for humidity is high, the air is generally dry for Aurangabad. The summer Aurangabad months are the driest when the relative humidity is generally Date 1941 -1990 between 19 and 40% in the afternoons. Range in mm No. of years 301-400 2 From July till September, the monsoon sets in, with the city receiving 401-500 1 moderate rainfall. The annual average rainfall received by it amounts 501-600 7 to somewhere around 725 mm, with most of it being received in the 601-700 15 monsoon season.13 701-800 5 801-900 15 Table shows frequency of annual rainfall observed in 48 years for 901-1000 0 Aurangabad city.3 1001-1100 3 Table showing annual rainfall observed in 48 years 12 Manual of tropical housing and building by O.H. Koenigsberger 13 Climate of Maharashtra by Metrological department, India. SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 42
  43. 43. ‘Design with Sun’ – A solution for envelope Design 3.2.3 Sky conditions During the southwest monsoon season, the % 90+ 80 skies are generally heavily clouded or overcast. % 70 60 50 In the post monsoon season, the sky is 100 40 30 20 moderately clouded with increased amount in 10 <0 80 afternoons. In the rest of the year, the skies are mostly clear or lightly clouded. 60 Nearly half period of the year is clouded and 40 half period is clear. 20 At the May end cloudiness gets increased and in July it shows highest cloud cover. After some 0 Wk 4 8 12 16 20 24 28 32 36 40 44 48 52 drop in September it again increased in October Source – Autodesk Ecotect and November. Fig 35 Graph showing Aurangabad’s weekly average cloud cover for a Year 3.2.4 Solar radiation The amount of solar radiation may be influenced by some local factor. Horizontal plane above the ground is affected by local variations in atmospheric conditions. Atmospheric pollution, smoke, smog or dust and local cloud formations can produce substantial reductions. But both horizontal plane and vertical building surface may influenced by orientation of site, by nearby hills, even trees and existing buildings, which may cast a shadow over the site at certain times of the day.14 14 Manual of tropical housing and building by O.H. Koenigsberger SUVIDHA SAGAVE (M. Arch Environmental Architecture, 2010-11) Page 43