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Harvesting energy with solar panels and adaptive shading for building skins: A case study of an office building in Saudi Arabia

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Harvesting energy with solar panels and adaptive shading for building skins: A case study of an office building in Saudi Arabia

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Content HARVESTING ENERGY WITH SOLAR PANELS AND ADAPTIVE SHADING FOR BUILDING SKINS: A CASE STUDY OF AN OFFICE BUILDING IN SAUDI ARABIA by Hamad Abdullah Al Olayan A Thesis Presented to the FACULTY OF THE USC SCHOOL OF ARCHITECTURE UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree MASTER OF BUILDING SCIENCE May 2011 Copyright 2011 Hamad Abdullah Al Olayan ii Dedication I want to write something… Beyond the description… Does not know the customs… Sweeter than sweetness… More sublime than imagination… To… Whom taught me kindness and tolerance… whom taught me honesty and patience… whom taught me hope… whom taught me love and the honesty of senses… whom taught me life… My mother… I dedicate you my thesis iii Table of Contents Dedication ............................................................................................................................ii List of Tables ...................................................................................................................... vii List of igures ........................................................................................................................ ix Abstract ............................................................................................................................ xvii CHAPTER 1: INTRODUCTION ............................................................................................................. 1 1-1. Preface ..................................................................................................................... 1 1-2. The Site of the Saudi Solar Village project ............................................................... 2 1-2-1. Location ............................................................................................................. 2 1-2-2. Geography ......................................................................................................... 3 1-3. Riyadh Climate ......................................................................................................... 3 1-4. The Benefits of Solar Radiation ................................................................................ 4 1-5. The Disadvantages of Solar Radiation...................................................................... 4 1-6. How could the people in the past cope with the heat of the sun ........................... 5 1-7. Life in the Villages: ................................................................................................... 6 1-8. Life in the Desert ...................................................................................................... 6 1-9. Day lighting in Riyadh ............................................................................................... 7 1-10. Latitude 24° 41'N Sun Path ..................................................................................... 8 1-11. Guidelines to Design for Riyadh Climate (Design Guidelines, 2011) ................... 10 1-12. The Saudi Solar Village ......................................................................................... 13 1-12-1. Geographical location ................................................................................... 14 1-12-2. The Solar Village currently consists of the following facilities ...................... 15 1-13. The Saudi Solar Village Project ............................................................................. 16 1-15. Building Description ............................................................................................. 18 1-16. The main factors of the research statement ....................................................... 20 1-16-1. The Shape ...................................................................................................... 20 1-16-2. Generate solar energy ................................................................................... 22 1-16-3. Reduce the annual energy consumption ...................................................... 22 1-16-4. The quality of lighting ................................................................................... 23 1-16-5. Improve the flow of air ................................................................................. 24 CHAPTER 2: PROBLEMS .................................................................................................................... 26 2-1. Introduction ........................................................................................................... 26 2-2. Is using a sun tracking system important? ............................................................. 29 2-2-1. Disadvantages of the system .......................................................................... 30 iv 2-2-2. Advantages of the system ............................................................................... 31 2-3. Preventing Self-Shading on the PV Panels ............................................................. 32 2-4. Shape and configuration ........................................................................................ 33 2-5. Will the solar panel pay for itself? ......................................................................... 35 2-6. Software Studies .................................................................................................... 36 2-7. The Sun Angles Studies .......................................................................................... 37 2-7-1. ArchiCAD Analysis ........................................................................................... 37 2-7-2. Revit- Solar Radiation ...................................................................................... 38 2-8. Solar Energy Generation ........................................................................................ 39 2-8-1. Photovoltaic Geographical Information System (PGIS) .................................. 39 2-8-2. PVCDROM ........................................................................................................ 40 2-9. The Studies for Reducing Energy Consumption ..................................................... 41 2-9-1. EcoDesigner ..................................................................................................... 41 2-9-2. DesignBuilder .................................................................................................. 41 CHAPTER 3: BACKGROUND.............................................................................................................. 43 3-1. Preface ................................................................................................................... 43 3-2. Photovoltaic cells ................................................................................................... 43 3-3. Solar radiation ........................................................................................................ 45 3-4. Angles of inclination ............................................................................................... 46 3-5. The Solar Unit and characteristics ......................................................................... 48 3-6. The position of units in the site or building envelope ........................................... 49 3-7. Case Study 1 ........................................................................................................... 50 3-8. Sun breakers........................................................................................................... 53 3-8-1. Natural breakers.............................................................................................. 53 3-8-2. Environmental function .................................................................................. 53 3-8-3. Structural Functions ........................................................................................ 54 3-8-4. Coordinating of Aesthetic ............................................................................... 54 3-8-5. Phenomenon of Desertification ...................................................................... 55 3-9. Elements of shading in an earlier time in the region ............................................. 55 3-10. Architectural elements of shading ....................................................................... 57 3-10-1. Means of Shading .......................................................................................... 57 3-11. How can sun breakers manipulate airflow? ........................................................ 60 3-12. Case Study ............................................................................................................ 61 CHAPTER 4: DATA ................................................................................................................................ 63 4-1. Introduction ........................................................................................................... 63 4-2. Solar Radiation at specified positions .................................................................... 65 4-2-1. Comparison of the solar radiation between the flat shape and the pyramid with 25cm depth:....................................................................................................... 65 v 4-2-2. Comparison of the solar radiation between the flat shape and the two-faced pyramid with 25cm depth ......................................................................................... 67 4-2-3. Comparison of the solar radiation between the flat shape and the pyramid with 35cm depth ........................................................................................................ 69 4-2-4. Comparison of the solar radiation between the flat shape and the two-faced pyramid with 35cm depth ......................................................................................... 71 4-2-5. Comparison of the solar radiation between the flat shape and the pyramid with 45cm depth ........................................................................................................ 73 4-2-6. Comparison of the solar radiation between the flat shape and the two-faced pyramid with 45cm depth ......................................................................................... 75 4-3. Calculating the solar radiation using Photovoltaic Geographical Information System PGIS ................................................................................................................... 77 4-3-1. Calculating the solar radiation for the flat surface using PGIS ....................... 78 4-3-2. Calculating the solar radiation for the 25cm pyramid at 24: using PGIS ....... 80 CHAPTER 5: THE MODULE AND THE ARRAY ........................................................................... 83 5-1. Introduction ........................................................................................................... 83 5-2. Maximize sun exposure on surface area and how this will reflect in the projection area .............................................................................................................. 83 5-2-1. Using the four faces of the pyramid for photovoltaics on the southern façade ........................................................................................................................ 83 5-2-2. Using two top faces of the pyramid for photovoltaics on the southern façade ................................................................................................................................... 86 5-2-3. Solar Radiation on panels rotated toward the west at different angles ..... 87 5-2-4. Solar Radiation on four-faced panels rotated at different angles to west ..... 88 5-2-5. Solar Radiation on two-faced panels rotated at different angles to west: . 89 5-3. Determination of the final form ............................................................................ 90 CHAPTER 6: THE EFFECTS OF THE SHADING SYSTEM ON THE BUILDING AND THE USERS ........................................................................................................................................................ 92 6-1. Reducing the annual energy consumption ............................................................ 92 6-2. Does not cause shading on neighboring modules ................................................. 94 6-3. To fit the panels to the façade ............................................................................... 95 6-4. Avoid blocking the view ......................................................................................... 97 6-5. To create a shape that is easy to implement; not to require a custom shape from the photovoltaic manufacturers ................................................................................. 101 6-5-1. The form of the structural support system is able to support the installation of photovoltaic panels ............................................................................................. 101 6-5-2. The exterior environmental space shaped by the system ............................ 102 CHAPTER 7: CONCLUSION ............................................................................................................. 104 7-1. Summary .............................................................................................................. 107 vi CHAPTER 8: SUGGESTED FUTURE WORK ............................................................................... 109 BIBLIOGRAPHY ................................................................................................................................... 111 APPENDIX ............................................................................................................................................. 113 Appendix A. ................................................................................................................. 113 Appendix B. ................................................................................................................. 115 Appendix C. ................................................................................................................. 117 vii List of Tables Table. 1.1 Chart showing average climate data for Riyadh through various months. (Saudi Arabia Travel Guide, 2011) ...................................................................................... 3 Table. 1.2 Chart showing the altitude angles of the sun throughout the different seasons in Riyadh .............................................................................................................................. 9 Table. 1.3 Table describing the structural properties and materials for the building...... 19 Table 3.1 showing the optimal angle of inclination for harvesting solar energy according to a region’s latitude. (Landay Charler R., 2010). ................................................................................................. 46 Table.3.2 showing the amount of energy that can be harvested using different types of PV panels, SunPower panels have the highest energy efficiency. ................................... 49 Table.4-1. Total Yearly Radiation on 25 cm pyramid ........................................................ 66 Table.4-2. Total Amount of Radiation Obtained .............................................................. 66 Table.4-3Total Yearly Radiation on 25 cm pyramid .......................................................... 68 Table.4-4. Total Amount of Radiation Obtained .............................................................. 68 Table.4-5. Total Yearly Radiation on 35 cm pyramid ........................................................ 70 Table.4-6. Total Amount of Radiation Obtained .............................................................. 70 Table.4-7. Total Yearly Radiation on 35cm pyramid. ........................................................ 72 Table.4-8. Total Amount of Radiation Obtained .............................................................. 72 Table.4-9. Total Yearly Radiation on 45 cm pyramid ........................................................ 74 Table.4-10. Total Amount of Radiation Obtained ............................................................ 74 Table.4-11. Total Yearly Radiation on 45 cm pyramid ...................................................... 76 Table.4-12. Total Amount of Radiation Obtained ............................................................ 76 viii Table.4-13. Table shows the angles of inclination and azimuth of each pyramid ........... 78 Table.4-14. Total Amount of Radiation Obtained at different tilt angles; Left at 0° Right at 90° ................................................................................................................................. 79 Table.4-15. Total Amount of Radiation Obtained at different tilt angles; Left at 24° Right at 47° . ................................................................................................................................ 79 Table.4-16. Total Amount of radiation Obtained at different tilt angles; Left at 16° inclination and 8° azimuth (face1); Right at 16° inclination and -8° azimuth (face2). ..... 81 Table.4-17. Total Amount of radiation Obtainedat different tilt angles; Left at 32° inclination and 8° azimuth (face 3); Right at 32° inclination and -8° azimuth (face 4) ..... 81 Table 5-1. Describing the differences in surface area between the flat surface and three pyramids with different depths. ....................................................................................... 83 Table5-2. Total Yearly Radiation on flat, 25 cm, 35cm and 45cm pyramids at various tilt angles ................................................................................................................................ 84 Table5-3. Total Yearly Radiation received on two sides of flat, 25 cm, 35cm and 45cm pyramids for various tilt angles ........................................................................................ 86 Table5-4. Total Yearly Radiation of flat and 25 cm pyramids tilt to the west .................. 88 Table5-5. Total Yearly Radiation of two faces of flat and 25 cm pyramids rotated toward the west ............................................................................................................................ 89 Table.5-6. Total Yearly Radiation just the two top faces of the 25cm Pyramid at 24: .... 90 Table.A-1. Table shows the angles of inclination and azimuth of each pyramid. .......... 118 ix List of Figures Fig. 1.1 Left: Map showing various providences of Saudi Arabia. Right: World map showing the location of Saudi Arabia in green. .................................................................. 2 Fig. 1.2 Topographic Map of Saudi Arabia, mountainous regions dark brown, deserts beige, hills and flatlands shown in green. ........................................................................... 3 Fig. 1.3 Diagram showing the mechanism of a traditional Saudi solar cooking oven. ....... 4 Fig. 1.4 Ice Sculpture at Gendarmenmarkt Berlin to demonstrate the dangers of global Warming. ............................................................................................................................. 5 Fig. 1.5 picture shows the slots on the wall of the Bedouin tents ..................................... 7 Fig. 1.6 Diagram showing the average amounts of daylight in Riyadh throughout the different months of the year. ............................................................................................. 8 Fig. 1.7. Sun path chart for Riyadh city. .............................................................................. 8 Fig. 1.8 Diagram showing the effectiveness of overhangs in providing protection from the sun (Source: ClimateConsultant). ............................................................................... 11 Fig. 1.9 Diagram showing fountain within an internal courtyard structure. (Source: ClimateConsultant) ........................................................................................................... 11 Fig. 1.10 Diagram showing the effectiveness of ceiling fans in providing air circulation. (Source:ClimateConsultant) .............................................................................................. 11 Fig. 1.11 Diagram showing a structure, which uses earth massing for cooling and protection from the sun. (Source: ClimateConsultant). ................................................... 12 Fig. 1.12 Diagram showing the effectiveness of using fountains in a courtyard in order to humidify and cool incoming air. (Source: ClimateConsultant). ........................................ 12 Fig. 1.13 Diagram showing the use of trees and overhangs in order to provide shade from the sun on glazed facades. (Source: ClimateConsultant). ....................................... 12 Fig. 1.14 Diagram showing the techniques to orient broad surfaces away from direct western sun exposure. ...................................................................................................... 13 x Fig. 1.15 Diagram showing how solar heat gain can be mitigated by using reflective materials. (Source: ClimateConsultant). ........................................................................... 13 Fig. 1.16 Location map of the Solar Village (Red) in context of Riyadh city to the south. 14 Fig. 1.17 Arial images of Al-Uyayna the site of the Saudi Solar Village. ........................... 14 Fig. 1.18 Solar panel farm in Solar Village at Al-Uyana ..................................................... 15 Fig. 1.19 Site plan of Saudi Solar Village project ............................................................... 16 Fig. 1.20 Solar Village project, South Elevation. ............................................................... 17 Fig. 1.21 Solar Village Project, West Elevation ................................................................. 18 Fig. 1.22 Solar Village project perspective looking to northeast. ..................................... 18 Fig. 1.23 Perspective showing the building’s glass façade. .............................................. 19 Fig. 1.24 Diagram showing the process from which solar energy is harvested through panels, and distributed into the battery and transformer in order to convert solar energy into electrical. ................................................................................................................... 22 Fig. 1.25 Graph showing possible total energy savings per month, if passive methods are encompassed into the building design. (Source: Ecodesigner for Archicad). .................. 23 Fig. 1.26 Diagram showing how the pyramid panels will help to protect the interior spaces from unwanted heat gain from the direct exposure to the sun, while allowing indirect natural daylight to enter the offices. ................................................................... 24 Fig. 1.27 Diagram showing air flow patterns through a tube. As the size of the opening decreases, air pressure increases as well as air velocity. ................................................. 25 Fig. 2.1 Vernacular clay structures in Riyadh. The thick walls help to provide insulation from solar heat gain keeping the interior spaces cooler. ................................................. 27 Fig. 2.2 Qasr al-Farid, a Nabatean Tomb in Saudi Arabia combines Classical Greek elements with vernacular building practices. ................................................................... 28 Fig. 2.3 Contemporary high rise towers are designed to be completely dependent on mechanical cooling systems.............................................................................................. 28 xi Fig. 2.4 The Arab World Institute’s façade is designed to adapt itself to the changing positions of the sun........................................................................................................... 31 Fig. 2.5 Facade projection studies by Holder Mader & Alexander Stublic. The building grid is distorted according to a series of modifying parameters. ..................................... 32 Fig. 2.6 Diagram showing panels rotated at 90 degrees in order to block the perpendicular afternoon summer sun. ............................................................................. 33 Fig. 2.7 Results of shadow studies on various shapes, pyramid, cube, and flat (Source: Archicad) ........................................................................................................................... 34 Fig. 2.8 Diagram showing the solar exposure on panels throughout different times of the day for a spherical shaped panel. ..................................................................................... 35 Fig. 2.9 Diagram illustrating the purpose of the software programs used in the research ........................................................................................................................................... 37 Fig. 2.10 Proposed pyramid panel façade modeled in Archicad. ..................................... 38 Fig. 2.11 Total yearly cumulative radiation cast on a single pyramid shaped panel, modeled and tested using Solar Radiation for Revit Architecture2011. .......................... 39 Fig. 2.12 PGIS plot showing the amount of solar radiation according in different region 40 Fig. 2.13 Screenshot of PVCDROM showing the calculations for the optimal angle of inclination in solar panels to harvest the maximum amount of energy. ......................... 40 Fig. 2.14 Screenshot of EcoDesigner for Archicad showing the carbon footprint for the proposed building design of the Solar Village. ................................................................. 41 Fig. 2.15 Screenshot from DesignBuilder software showing the relationships between interior and exterior temperatures. ................................................................................. 42 Fig. 3.1 Map showing the amount of solar radiation throughout the world, highest amounts show in dark brown smallest in white. Note Saudi Arabia receives the largest amount of solar radiation in the earth. ............................................................................ 45 Fig. 3.2 Diagram showing the amount of solar radiation that is absorbed and reflected within the earth’s surface. ................................................................................................ 46 xii Fig. 3.3 Picture showing the relationship between the elevation angle of sun & angle of panel ................................................................................................................................. 47 Fig. 3.4 Chart showing the total solar radiation on the flat surface over one year for various angles of tilt. ......................................................................................................... 47 Fig. 3.5 Photograph of a typical photovoltaic panel. ........................................................ 48 Fig. 3.6 Diagram showing conventional methods which can be used to provide protection and insulation from solar heat gain. ............................................................... 49 Fig. 3.7 SIEEB Building exterior perspective. .................................................................... 50 Fig. 3.8 Sketch showing the concept for the photovoltaic terraces in the SIEBB building. ........................................................................................................................................... 51 Fig. 3.9 SIEEB Building exterior perspective. .................................................................... 51 Fig. 3.10 Exterior view of PV shaded terracing at SIEEB .................................................. 52 Fig. 3.11 SIEEB Building Section ........................................................................................ 52 Fig. 3.12 Photograph of residential building showing how trees can be used to provide protection from the sun. ................................................................................................... 54 Fig. 3.13 Date palms in the desert of Saudi Arabia. .......................................................... 55 Fig. 3.14 Photograph of traditional Marshrabia screens in Riyadh. ................................. 56 Fig. 3.15 Photograph of fixed horizontal louvers applied to a building façade in order to provide protection from the sun. ..................................................................................... 58 Fig. 3.16 Photograph showing vertical fins applied to a buildings western façade to provide protection from solar heat gain. ......................................................................... 59 Fig. 3.17 Metal horizontal louvers at Burj Khalifah.......................................................... 61 Fig. 3.18 Photograph showing photovoltaic panels applied to the horizontal louvers at Burj Khalifah. ..................................................................................................................... 62 xiii Fig.3-19 Section detail of horizontal overhangs at Burj Khalifah..................................... 62 Fig.4-1. Shadow studies on panel arrays for June 21, September 21, and December 21. (Source: Ecotect) ............................................................................................................... 65 Fig.4-2. 3D model of panels modeled in Revit Architecture. ............................................ 65 Fig.4-3. Diagram showing pyramid shaped panel divided into four equal faces. ............ 66 Fig.4-4. Chart Comparing Radiation obtained in flat panels versus 25cm pyramid panel. ........................................................................................................................................... 67 Fig.4-5. 3D model of panels top sides only modeled in Revit Architecture. .................... 67 Fig.4-6. Diagram showing pyramid shaped panel divided into two equal faces. ............. 68 Fig.4-7. Chart Comparing Radiation obtained in flat panels versus 25cm pyramid panel. ........................................................................................................................................... 69 Fig.4-8. 3D model of panels modeled in Revit Architecture. ............................................ 69 Fig.4-9. Diagram showing pyramid shaped panel divided into four equal faces. ............ 70 Fig.4-10. Chart Comparing Radiation obtained in flat panels versus 35cm pyramid panel. ........................................................................................................................................... 71 Fig.4-11. 3D model of panels modeled in Revit Architecture. .......................................... 71 Fig.4-12. Diagram showing pyramid shaped panel divided into two equal faces. ........... 72 Fig.4-13. Chart Comparing Radiation obtained in flat panels versus 35cm pyramid panel. ........................................................................................................................................... 73 Fig.4-14. 3D model of panels modeled in Revit Architecture. .......................................... 73 Fig.4-15. Diagram showing pyramid shaped panel divided into four equal faces. .......... 74 Fig.4-16. Chart Comparing Radiation obtained in flat panels versus 45cm pyramid panel. ........................................................................................................................................... 75 Fig.4-17. 3D model of panels modeled in Revit Architecture. .......................................... 75 xiv Fig.4-18. Diagram showing pyramid shaped panel divided into two equal faces. ........... 76 Fig.4-19. Chart Comparing Radiation obtained in flat panels versus 45cm pyramid panel. ........................................................................................................................................... 77 Fig.4-20. Picture shows the division that has made for the 25cm pyramid panel to be able to study in PGIS. ........................................................................................................ 78 Fig.5-1. 3D model of panels modeled in Revit Architecture. ............................................ 84 Fig.5-2. Total Yearly Radiation on arrays of flat, 25 cm, 35cm and 45cm pyramids for various tilt angles .............................................................................................................. 84 Fig.5-3. Picture shows the difference of projection area between the four different shapes. .............................................................................................................................. 85 Fig.5-4. 3D model of panels modeled in Revit Architecture. ............................................ 86 Fig.5-5. Total Yearly Radiation received on two sides of flat, 25 cm, 35cm and 45cm pyramids for various tilt angles ........................................................................................ 86 Fig.5-6. Total Yearly Radiation rotated at different angles to west ................................. 88 Fig.5-7. Rotating the panels with four faces from the south toward the west (from the left: 0 o , 12 o , 24 o , 36 o , 44 o ). ............................................................................................. 89 Fig.5-8. Total Yearly Radiation received by two-faces rotated at different angles toward the west ............................................................................................................................ 89 Fig.5-9. Rotating the two top faces of the panels from the south toward the west (from the left: 0 o , 12 o , 24 o , 36 o , 44 o ) ........................................................................................ 89 Fig.5-10. Total Yearly Radiation just the two top faces of the 25cm Pyramid at 24: tilt angle .................................................................................................................................. 90 Fig.5-11. The final form of the unit with description of each part. .................................. 91 Fig.6-2. Examine shade and shadow on the panels for June 21 (Ecotect) ....................... 94 Fig.6-3. Study shade and shadow on the panels for September 21 (Ecotect) ................. 94 xv Fig.6-4. Observe the shade and shadow on the panels for December 21 (Ecotect). ....... 95 Fig.6-5. Picture shows the fitting into the façade in three different forms. .................... 95 Fig.6-6. Picture shows the fitting into the façade in three different forms by the side surface area (cross sectional) ........................................................................................... 96 Fig.6-7. shows how the pyramid shape will gain the solar radiation even from shallow angles ................................................................................................................................ 97 Fig.6-8. The perspective from the inside to outside of the building 21 June ................... 98 Fig.6-9. Looking from the interior to exterior of the building 21 September .................. 98 Fig.6-10. Looking from the interior to exterior of the building 21 December ................. 98 Fig.6-11. The final form of the shading system and shows the relative amounts pf photovoltaic and glass. ..................................................................................................... 99 Fig.6-12. Defending the exterior of the building from the sun 21 June ......................... 100 Fig.6-13. Protecting the southern façade of the building from the solar heat gain 21 September ....................................................................................................................... 100 Fig.6-14. Protecting the building from the solar heat gain on 21 December ................. 100 Fig.6-15. Truss and Panel Assembly. ............................................................................... 102 Fig.6-16. The space between the building and shading system has helped to fill the space with trees and palms which created an intimate space. ............................... 103 Fig.7-1. Divide the pyramid into pieces as it is shown to give the ease of building a relatively asymptotically to the pyramid. .................................................. 106 Fig.7-2. The main objectives of the research. ................................................................. 107 Fig.A-1. Total Amount of Radiation Obtained at 0: Left; flat panel, Right; pyramid. ..... 113 Fig.A-2. Total Amount of Radiation Obtained at 24: Left; flat panel, Right; pyramid. ... 113 xvi Fig.A-3. Total Amount of Radiation Obtained at 47: Left; flat panel, Right; pyramid. ... 113 Fig.A-4. Total Amount of Radiation Obtained at 90: Left; flat panel, Right; pyramid. ... 114 Fig.A-5. Total Amount of Radiation Obtained at 0: Left; flat panel, Right; pyramid. ..... 115 Fig.A-6. Total Amount of Radiation Obtained at 24: Left; flat panel, Right; pyramid. ... 115 Fig.A-7. Total Amount of Radiation Obtained at 47: Left; flat panel, Right; pyramid. ... 115 Fig.A-8. Total Amount of Radiation Obtained at 90: Left; flat panel, Right; pyramid. ... 116 Fig.A-9. Total Amount of Radiation Obtained at 0: Left; flat panel, Right; pyramid. ..... 117 Fig.A-10. Total Amount of Radiation Obtained at 24: Left; flat panel, Right; pyramid. . 117 Fig.A-11. Total Amount of Radiation Obtained at 90: Left; flat panel, Right; pyramid. . 117 Fig.A-12. Total Amount of Radiation Obtained at 90: Left; flat panel, Right; pyramid. . 118 Fig.A-13. Chart shows the angles of inclination and azimuth of each pyramid. ............ 119 Fig.A-14. All angles that was potential in the study. ...................................................... 119 Fig.A-15. The annual energy consumption of the building as designed. ........................ 120 Fig.A-16. The annual energy consumption of the building by adding the shading elements in the south façade. ........................................................................................ 121 xvii Abstract Problems with air conditioning and temperature control in the central region of Saudi Arabia are one of the biggest challenges facing architects today. This is what has driven scholars to find a number of ways to resolve this crisis. As a result, researchers have considered the use of adaptive façade shading systems as a possible solution to control and reduce solar heat gain in office buildings. It is well known that in the central region of Saudi Arabia the temperatures can reach up to 125 degrees Fahrenheit (51:C). This is the reason why researchers are trying to develop a new building skin system using solar panels in the surfaces of the façade as a source of solar energy for the building as well as to reduce the amount of solar heat gain inside the space. The use of these systems will help to drastically reduce energy costs because of their ability to convert thermal energy into electrical energy. The use of solar panels as skin for building facades is studied in two aspects. First, the use of panels is studied as a shading system in order to protect the building from solar heat gain. This involves studying the different angles of the sun throughout the day and creating a shading system, which may be dynamic and adaptive. Second, the use of solar panel façade systems is studied for their ability to harvest solar energy and turn it into electric energy in order to power building functions. This is a very important aspect since it allows the users of the structure to decrease external energy usage and save on costs. The idea of an adaptive building façade system incorporates the possibility of making the panels move automatically in response to the position of xviii the sun. Such kinetic façade systems also give the building a new form at every moment and on every surface. In short, the principal intentions of this effort are to reduce reliance on external electric power sources to reduce the penetration of the sun's rays into internal spaces of the building, and to mitigate the amount of solar heat gain. Additionally, this project will study ways to take advantage of the huge amount of sun exposure in the region to convert solar energy into electric energy. The use of a pyramid shape for the panels was arrived at a series compilation of studies in order to optimize the amount of solar power. The purpose of this shape is to provide more surface area, and also to restrict and simplify the panels’ movement to the vertical direction only rather than both vertical and horizontal movements. The movement of the panels on the façade will provide the ability to adjust the passage and quality of light, adjust the flow of air, and finally to block the sun, and reduce the temperature of air stream. In this thesis, the researcher will try to address the effectiveness of the elements that were invented to reduce air conditioning loads significantly. Additionally, this project will study ways in which to assemble elements into a second surface (building skin) to help reduce electrical loads of the building. The façade will also serve as a shading device and insulation element for the building. By increasing the depth of the pyramid elements, the total surface area is also increased, potentially allowing more solar energy to be harvested. However, the pyramid depth must be designed to minimize shadowing xix between elements. The goal of the design is to maximize the amount of radiation falling on the surface panels thus increasing the amount of electricity generated through solar energy. The use of adaptive façade systems can help to drastically reduce cooling energy loads by preventing solar overheating while simultaneously harvesting the sun's energy in order to produce clean electrical power, ultimately helping to reduce pollution in the environment. 1 Chapter 1: Introduction 1-1. Preface Energy technologies occupy a prominent place for the Kingdom of Saudi Arabia. The energy sector is the main engine of the country's development and economic renaissance. The electricity sector faces challenges in Saudi Arabia in order to meet the demands for the growing consumption of electricity, which is the basis of economic and social development. The estimated annual growth rate of electricity consumption in the Kingdom is 6.4%. In order to meet this need, the Kingdom needs to construct more power plants and distribution systems. “The estimated capacity needed for electricity generation in the year 2023 is about 59,000 megawatts, compared to generation capacity existing in the year 2001, which was around 25,000 megawatts”. (Institute of Energy research, 2009) In order to find scientific solutions to provide to this growing demand, the Kingdom is currently trying to improve the systems of electricity generation, transmission and distribution and use. Renewable sources of energy will be the prevalent source of power for the Kingdom of Saudi Arabia in the future. However, due to the current availability of oil as the primary energy source, there is little incentive to develop the technology to harvest renewable energy. Oil is a non-renewable source of energy; the problem arises as to what sources of power the country can use when it runs out of oil. The renewable energy sector needs to provide a significant share of the energy production in the future. This involves 2 creating affordable renewable energy sources easily available to the urban public as well as to those in remote areas. The need is to develop techniques of high efficiency, economical in fuel consumption, with limited impact on the environment. The energy production plan to be developed will be based on input and feedback from users of energy technologies and the relevant authorities in this sector in the Kingdom, including government institutions, universities, and industries. It is currently being drafted based on the opinions from relevant authorities through small workshops; in addition to a comprehensive workshop, which received the participation of more than forty participants. 1-2. The Site of the Saudi Solar Village project 1-2-1. Location The Kingdom of Saudi Arabia, is an Arab state located in the Arabian Peninsula latitude 24° 41'N, Longitude 46° 42'E. It accounts for three-fifths of the total area of the Arabian Peninsula. It is bounded to the north by Iraq, Jordan, and Kuwait, to the east by UAE, Qatar, Bahrain and the Persian Gulf, to the south by the Sultanate of Oman and Yemen, and to the west by the Red Sea. (Saudi Arabia, Wikipedia, 2011) Fig. 1.1 Left: Map showing various providences of Saudi Arabia. Right: World map showing the location of Saudi Arabia in green. 3 1-2-2. Geography Saudi Arabia's geography is varied. From the humid western coastal region (Tehamah) on the Red Sea, the land raises from sea level to a peninsula-long mountain range (al-Hejaz) beyond which lies the plateau of Nejd in the center. The southwestern region has mountains as high as 3,000 m (9,800 ft) and is known for having the greenest and freshest climate in all of the country; this attracts many Saudis to resorts such as Abha in the summer months. The east is primarily rocky or sandy lowland continuing to the shores of the Persian Gulf. The geographically hostile Rub' al Khali ("Empty Quarter") desert along the country's imprecisely defined southern borders contains almost no life. (Saudi Geological Survey, 2011) Fig. 1.2 Topographic Map of Saudi Arabia, mountainous regions dark brown, deserts beige, hills and flatlands shown in green. 1-3. Riyadh Climate In general, conditions in Riyadh are dry and hot, but the city does receive about four inches (102mm) of rain a year, most of it falling between January and May. In the summer, hot winds can send temperatures soaring up to 126° F (52° C). In winter, it can be surprisingly chilly, however, particularly at night when the thermometer can plunge below freezing. The best months in Riyadh, when days are pleasantly tolerable and nights are cool, are between October and May. (World Climate Zones, 2007) Table. 1.1 Chart showing average climate data for Riyadh through various months. (Saudi Arabia Travel Guide, 2011) Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average Max Temp 31.5 (89) 34.8 (95) 38.0 (100) 42.0 (108) 45.1 (113) 49.0 (120) 52.0 (126) 49.8 (122) 44.5 (112) 41.0 (106) 36.0 (97) 31.0 (88) 48.0 (118) Average High Temp 20.2 (68) 23.0 (73) 27.3 (81) 33.3 (92) 39.1 (102) 42.4 (108) 43.5 (110) 43.2 (110) 40.3 (105) 35.0 (95) 27.7 (82) 22.0 (72) 43.5 (110) Average Low Temp 9.0 (48) 11.0 (52) 15.0 (59) 20.3 (69) 25.7 (78) 27.6 (82) 29.1 (84) 28.8 (84) 25.7 (78) 20.9 (70) 15.4 (60) 10.6 (51) 9.0 (48) Rainfall Inches (0.46) (0.33) (0.97) (0.88) (0.18) (0) (0) (0.01) (0) (0.07) (0.31) (0.51) (0.31) Humidity 47 38 34 28 17 11 10 12 14 21 36 47 26 4 Temperatures are characterized as continental climate desert: generally hot in summer and cold in winter, with an average maximum temperature of 45 degrees Celsius and a minimum of 8 degrees Celsius, while the average rainfall rate is 43 mm with around 30% humidity. 1-4. The Benefits of Solar Radiation The Kingdom of Saudi Arabia is largely affected by its hot desert climate. It has experienced extreme heat and water shortages for hundreds of years. Historically, this led the Saudi society to form clans and societies, which centered around oases. The requirement to eco-exist with the harshness of the sun found a number of ways to take advantage of these rays. For example: the creation of solar ovens for cooking temperatures of up to 218 ° F, by using some simple techniques and to create a degree of heat sufficient to cook certain types of food. Fig. 1.3 Diagram showing the mechanism of a traditional Saudi solar cooking oven. 1-5. The Disadvantages of Solar Radiation Solar radiation makes a strong impact on the buildings and items exposed to the sun directly, often causing damage and destruction. In this sense, it is essential to provide 5 protection from the elements by shading of the building in order to mitigate heat gain by solar radiation. Providing protection from solar heat gain can reduce up to 10% of a building’s total energy consumption according to studies conducted on software simulation programs. It is notable that the vernacular architectural elements that were modeled and tested in the software existed in previous eras in architecture Arabia. Fig. 1.4 Ice Sculpture at Gendarmenmarkt Berlin to demonstrate the dangers of global Warming. 1-6. How could the people in the past cope with the heat of the sun People have lived in the Arabian Peninsula for thousands of years without air conditioning and refrigeration. These people were typically villagers who worked in agriculture and livestock. Farmers and herders created lifestyles that were compatible with the desert environment of the peninsula. Originally, people in the Arabian Peninsula were divided by their occupations into two groups: city or village dwellers and the residents of the desert. 6 1-7. Life in the Villages: The environmental benefits of courtyards are characterized by the ability to modify temperature, allowing the movement of air through the building and providing a breeze and using pre-cooled thermal mass that helps to mitigate air temperatures. However, the courtyard does not play this role alone in traditional building, since there are other elements such as the organization of spatial uses that play a role in the system. This often results in the construction of multi-story courtyard structures. For example, the space located on the ground floor loft oversees the courtyard, for example, the Iwan resides here in particular in public buildings such as mosques, schools, and some agencies. 1-8. Life in the Desert In Bedouin tents, the residents were able to construct dwellings from local materials such as wooden poles and wool in order to provide shelter for their families. In these tents, we find that the Bedouin created a way to adapt to the hot desert climate using wool as natural insulation on the roof to create a barrier. This concept is similar to the way in which contemporary architects insulate buildings at the present time. Additionally, the Bedouin tent allowed air to enter by leaving a space between ceiling and the walls of the tent in order to ventilate and cool the interior space. The Bedouin has viewed their homes as umbrellas to shield them from direct sunlight and allow air to enter through the tiny openings. 7 Fig. 1.5 picture shows the slots on the wall of the Bedouin tents 1-9. Day lighting in Riyadh In a city with a desert climate such as Riyadh, clouds are almost miracles: typically from sunrise until sunset you find clear sky and high solar radiation. Most of the day provides broad daylight (shown in the yellow zone on Fig. 1.6. The timescale is shown on both sides of this Figure). The amount of daylight received throughout the day varies depending on the yearly seasons. During the spring and summer months the sun rises as early as four in the morning and sets around 6pm. Due to the small amount of cloud coverage that occurs year round, there is good opportunity to take advantage of natural day lighting in the interior spaces of Riyadh. However, when using daylight special consideration must be taken to prevent direct light and unwanted solar heat gain. 8 Fig. 1.6 Diagram showing the average amounts of daylight in Riyadh throughout the different months of the year. 1-10. Latitude 24° 41'N Sun Path The sun path refers to the seasonal changes, determined by the location of a region in relationship to the manner in which the Earth rotates, and revolves around the sun. The relative position of the sun is a major factor influencing heat load in buildings and determining the performance of solar energy systems. Accurate knowledge of site- specific path of the sun and the weather conditions is necessary in order to make decisions regarding the position and orientation of solar collectors, landscaping, shading for summer months, and the use of cost-effective solar trackers. Fig. 1.7. Sun path chart for Riyadh city. 9 Table. 1.2 Chart showing the altitude angles of the sun throughout the different seasons in Riyadh Riyadh is located at latitude 24 north and longitude 46 east. The movement of the sun changes gradually from sunrise the morning, reaching the highest position in the middle of the day and descending gradually to the west. These factors must be taken into account in the design of the building skin and shading devices in order to create a building’s character and provide protection from the sun. Time Winter Solstice Equinox Solstice Summer Solstice The Position in the sky 9:00 AM 3:00 PM 25 o 39 o 50 o 10:00 AM 2:00 PM 35 o 52 o 62 o 11:00 AM 1:00 PM 40 o 61 o 75 o 12:00 PM Noon 43 o 66 o 89 o 10 At 24 degrees latitude, designers are dealing with a difficult situation when it comes to protecting buildings from solar radiation. In the summer, the sun angle rises from nine in the morning until the middle of the day from 50 degrees to 89 degrees. This is a factor, which influences the design of environmentally responsive facades. However, a sharp increase in the angle of altitude of the sun is also present at the winter solstice and at the equinoxes. 1-11. Guidelines to Design for Riyadh Climate (Design Guidelines, 2011) The main issue concerning sustainable design is to design buildings which are responsive to the local climate. What is the appropriate way in which to design buildings for an arid desert climate such as Riyadh? Many techniques have been developed in order to create sustainable buildings for hot desert climates such as Riyadh. Professor Murray Milne states “avoid sunlight as much as possible”. In keeping with the previous statement, Climate Consultant provides the following, eight design guidelines: 1- Provide window overhangs (designed for this latitude) or operable sunshades (extend in summer, retract in winter) in order to reduce or eliminate air conditioning. 11 Fig. 1.8 Diagram showing the effectiveness of overhangs in providing protection from the sun (Source: ClimateConsultant). 2- Traditional homes in hot windy dry climates use enclosed well shaded courtyards, with a small fountain to provide wind-protected microclimates. Fig. 1.9 Diagram showing fountain within an internal courtyard structure. (Source: ClimateConsultant) 3- On hot days ceiling fans or indoor air motion can make it seem cooler by at least 5 degrees F (2.8C) thus less air conditioning is needed. Fig. 1.10 Diagram showing the effectiveness of ceiling fans in providing air circulation. (Source:ClimateConsultant) 4- In very hot dry climates earth sheltering or occupied basements benefit from earth cooling in summer (the earth stays near average annual temperature). 12 Fig. 1.11 Diagram showing a structure, which uses earth massing for cooling and protection from the sun. (Source: ClimateConsultant). 5- Humidify hot dry air before it enters the building from enclosed outdoor spaces with spray-like fountains, misters, wet pavement, or cooling towers. Fig. 1.12 Diagram showing the effectiveness of using fountains in a courtyard in order to humidify and cool incoming air. (Source: ClimateConsultant). 6- Minimize or eliminate west facing glazing to reduce summer and fall afternoon heat gain. Fig. 1.13 Diagram showing the use of trees and overhangs in order to provide shade from the sun on glazed facades. (Source: ClimateConsultant). 7- For passive solar heating face most of the glass area south to maximize winter sun exposure, but design overhangs to fully shade in summer. 13 Fig. 1.14 Diagram showing the techniques to orient broad surfaces away from direct western sun exposure. Northern exposures provide good daylight, and southern exposures can be easily shaded with balconies and overhangs. (Source: ClimateConsultant). 8- Use light colored building materials and cool roofs (with high reflectivity and emissivity) to minimize conducted heat gain. Fig. 1.15 Diagram showing how solar heat gain can be mitigated by using reflective materials. (Source: ClimateConsultant). 1-12. The Saudi Solar Village The Saudi Solar Village Project, as it is called, is one of several solar experiments being sponsored by the Saudi Arabian National Center for Science and Technology and the United States Department of Energy as part of a joint cooperation agreement signed in 1977. Under the five-year agreement, each country was to provide $50 million for specific technical projects. The agreement was extended last year for three more years to enable all of the $100 million to be committed. The solar village, which has cost about $26 million, is the largest project to date. (JUDITH MILLER, 1983) The project is located specifically in Al-'Uyayna, a small village in central Saudi Arabia, located some 30 km northwest of the capital Riyadh. Al-'Uyayna is an ancient town dating back to the age of pre-Islamic history. Currently it is a suburb of Wadi Hanifa, located northwest of the city of Riyadh. Al-'Uyayna became one of the largest 14 settlements due to the fertile soil and abundant water of the large valleys, this allowed active trade and scientific movements to flourish. Fig. 1.16 Location map of the Solar Village (Red) in context of Riyadh city to the south. 1-12-1. Geographical location The Solar Village is located in Al-'Uyayna at the Hanifa valley northwest of Riyadh province, close to Dir'iya. The distance between them and the capital Riyadh about (30) kilometers and an estimated total area of (4930) hectare. ('Uyayna, Wikipedia, 2011) Fig. 1.17 Arial images of Al-Uyayna the site of the Saudi Solar Village. The facility was created in 1977 under the name of “The Village Project” in order to provide an electricity capacity of 350kW to some of the villages around the city of Riyadh, Al-'Uyayna Jubaila. The project then evolved to represent the first marker in 15 research for the implementation of solar energy projects at the local and regional scale. This evolution reflects the remarkable achievement of the King Abdulaziz City for Science and Technology in the field of applied research. The Solar Village is also the first fruit of a successful US-Saudi Arabian Technical Cooperation for the exploitation of solar energy in remote areas. Fig. 1.18 Solar panel farm in Solar Village at Al-Uyana 1-12-2. The Solar Village currently consists of the following facilities A - Engineering Workshop: Contains the workshop with engineering machinery and equipment for mechanical and electrical use in metal turning and the maintenance and calibration of some equipment. It is also a workshop provided for training of the cadres of local technicians and workers. The workshop also implements other activities of art to serve some sections and departments in the city. B - Computer Labs These feature the latest personal computers, machinery and essential accessories. Additionally they include some devices directly implementing laboratory tests, and also 16 provide laboratory services and analysis of simulation and processing of data resulting from laboratory experiments and research projects. C - The Warehouse This facility is available in the solar village to secure raw materials for the implementation of ongoing projects at the Institute. It also includes a database of the inventory of all materials consumed annually and the number of devices and equipment available at the Institute. 1-13. The Saudi Solar Village Project Location: Al-'Uyayna a village in central Saudi Arabia, located some 30 km northwest of the Saudi capital Riyadh. Area: 22,000 m2. Owner: King Abdul-Aziz City of Science and Technology Consultant: Zohair Faiz & Partner. Floors: 4 floors. Number of users: 180 persons. Fig. 1.19 Site plan of Saudi Solar Village project 17 The project is located in the south-west of the village on a hillside at the entrance of the village and overlooking surrounding farms of different areas. It is connected to the solar village’s services and infrastructure. 1-14. Architectural Description The project is a research center hosted by the King Abdul-Aziz City for Science and Technology for various technical fields such as energy research, telecommunications, space research and advanced electronics. The projects location at the foothills in combination with the modern selection of materials and external cladding of buildings create an impressive and unique building compound. The general project reflects an architectural style that attempts to influence the public’s attitudes toward sustainability through the building’s image. The project compound consists of four buildings, which are currently being used as research offices and laboratories. Each building is four stories in height. The main lobby has a unique glass roof, which provides a special gathering space for art exhibitions and conferences dedicated to the fields of science and technology. Fig. 1.20 Solar Village project, South Elevation. 18 Fig. 1.21 Solar Village Project, West Elevation Fig. 1.22 Solar Village project perspective looking to northeast. 1-15. Building Description The structure is an office building, with research laboratories based in the ground and first floor, and offices on the second and third floor. The building is 70 meters long and 25 meters wide, with a height of 18 meters. The building’s basic facade element is glass curtain wall unit 1.12 meters wide and four meters high. The exterior walls of the building are a precast concrete with a thickness of 20 cm. The roof is a pre-cast concrete, 35 cm thick. Air-conditioning is provided through a centralized system which cools the building using chilled water from a district cooling system which is part of the city services. 19 Walls Roof Windows Floors HVAC 8 cm insulation +Air gap 4 cm+ 20 cm Concrete Block +Plaster + painting. Concrete slab + insulation 18 cm + 5 cm Gravel. Low E Double U=0.35 SHGC=0.15 Slab on Grade. Heating and cooling are electric systems. Table. 1.3 Table describing the structural properties and materials for the building. We know that glass offices allows for occupants to have a pleasant view to the outside improving the mood of the employee. However, the extensive use of glass, especially in offices, has created a series of problems for those working in the spaces due to high temperatures caused by solar radiation through the glass and brightness of glare in the eyes of occupants. Fig. 1.23 Perspective showing the building’s glass façade. In order to minimize solar heat gain building facades should be designed depending on their orientation to the sun. Glass curtain walls are placed on the north side in order to take advantage of indirect sunlight, while panels and shading devices are used on the 20 south, east, and western facades in order to avoid unwanted heat gain. However, this is not a complete solution to the problem, especially when considering the amount of energy a building will consume during its lifetime. Shading systems for glass curtain walls provide the opportunity for exploration and experimentation in the city of Riyadh. The creation of a responsive facade that uses solar panels to provide shade and harvest the sun’s energy provides the opportunity to create a self-sustaining building that does not cause pollution to the environment. 1-16. The main factors of the research statement This research addresses several issues in sustainability for adaptive building façade. The four factors driving the design for the façade are: 1-16-1. The Shape Designing the façade for the KACST building requires studying the best ways to provide shade in order to prevent overheating by solar radiation, particularly in the southern façade. The present research began by studying all existing buildings with a similar function. The results showed that the best means to provide shading while allowing daylight is to prevent direct sunlight from entering the space while allowing soft diffused daylight. The client desired for both shading and solar energy to be provided at a specific area (the southern façade of the building). Therefore, the target is to collect the largest possible amount of energy from sunlight and convert it into electrical energy in order to assist in the operational process of the building. Due to the amount of area that 21 was available for generation of solar energy, the research requires creating a shape that will maximize the amount of photovoltaic surface area that is exposed to solar radiation. The existing southern façade is only 70 meters in length and 18 meters in height; this provides only 1260 square meters from which to generate energy. Although the existing area is enough to harvest solar energy, the present research explores the design of a three dimensional shape in order to obtain additional surface area in order to collect additional power. The research consists of a various strategies in order prevent direct sunlight from entering the space while simultaneously harvesting solar energy. 1 – To obtain the largest surface area exposed to direct sunlight possible. 2 – To create a shape that is easy to implement. 3 – The form is not allowed to shade the neighboring units. 4 - The structural system should be simple and uncomplicated. 5 – The form is able to support the installation of photovoltaic panels on it. 6 - Not to request a custom shape from the photovoltaic manufacturers. The challenge was how to devise a three-dimensional form that would take advantage of the path of the sun from morning until sunset. Additionally, the strategy for the design of the shape was influenced by other factors such as construction budget and manufacturing capabilities. These two elements helped to simplify the design choices. The shape design was based on the principle of generating the highest output of energy 22 by obtaining the largest amount of projected surface area of photovoltaic without shading adjacent elements. 1-16-2. Generate solar energy Solar energy will be harvested by photovoltaic panels installed in the shading system in order to provide part of the power needed to operate the building. The goal is to take advantage of the huge amount of sun exposure in the region. Solar energy is emitted light and heat from the Sun. Fig. 1.24 Diagram showing the process from which solar energy is harvested through panels, and distributed into the battery and transformer in order to convert solar energy into electrical. Photovoltaic technology is the use of active solar photovoltaic panels to convert sunlight directly into electrical energy. Application of this solar technology includes the process of selecting suitable sites in order to maximize the panels’ direct exposure to the sun. Solar energy technologies are already producing abundant amounts of energy in many parts of the world. 1-16-3. Reduce the annual energy consumption Annual electric energy consumption will be reduced by adding elements of shading to reduce the cooling load of the building by passive means without changing the 23 mechanical systems of the building. The present research involves working to design the elements of shade in the southern facade of the building in order to reduce incoming sunlight inside offices. Shading elements will be built on the existing structure, which is composed of a steel frame. The shading devices will be installed at an angle; this is done in order to create a space between the building and the shading screens. This results in the creation of a ventilated void space that may additionally help to reduce internal heat gain. The transitional layers helps to cool the air (by providing shading) before it enters the interior office spaces. If large enough the shaded open space between the building and shading system can be used as a recreational area for workers in their leisure time. Fig. 1.25 Graph showing possible total energy savings per month, if passive methods are encompassed into the building design. (Source: Ecodesigner for Archicad). 1-16-4. The quality of lighting Diffused natural daylight will be provided in the internal spaces for the offices and laboratories. The shading systems will help to allow the spaces to achieve the required amount of daylight per square meter while blocking a large amount of direct solar radiation from entering the spaces. The issue becomes the quality of the general atmosphere in the interior spaces and the manner in which lighting is controlled will 24 become a crucial part of the methodologies that must be studied. In this situation the use of three-dimensional shading elements instead of flat surfaces will affect the quality of natural lighting within the offices. Research will investigate how this will be influenced by the shape of the pyramidal elements. One of the primary goals would be to allow diffuse light, while blocking direct solar gain. The secondary strategy would be to reflect a limited amount of direct solar into the building for lighting in the rear of the spaces. Fig. 1.26 Diagram showing how the pyramid panels will help to protect the interior spaces from unwanted heat gain from the direct exposure to the sun, while allowing indirect natural daylight to enter the offices. 1-16-5. Improve the flow of air The façade will work by providing natural ventilation inside the office spaces when such ventilation is desirable. One of the factors influencing the design of the building skin involves studying the amount of air flowing into the space and under what seasonal 25 conditions incoming airflow will help the users of the building to take advantage of natural ventilation. In addition to providing natural lighting, the research takes into consideration the possibility that there will be a significant change in the course of the flow of air through small openings between the panels. Natural airflow will be studied for its potential impact on cooling the outer surfaces of the building. Additionally airflow through the narrow spaces of the building facades will create an increased pressure and speed in incoming air flow which may help to increase the effectiveness of natural ventilation and reduce ambient temperatures in the interior spaces. However, the limited amount of research time was of the main reasons that prevented the completion of the research. Fig. 1.27 Diagram showing air flow patterns through a tube. As the size of the opening decreases, air pressure increases as well as air velocity . 26 Chapter 2: Problems 2-1. Introduction The research began by studying the existing conditions for the King Abdul Aziz City for Science and Technology. The goal is to create a façade system, which works with the existing conditions and provides a building with high efficiency, a building for the future that responds to the difficulties of climate and weather in an environmentally sensitive manner. The study involves the development of an innovative responsive façade system that is based on a series of existing sustainable practices from vernacular building types for hot arid climates. The responsive façade system will explore the aspect of sustainability in two ways: how to reduce cooling loads by providing shade, and how to harvest renewable energy from the sun. In the various uses of buildings in the Kingdom of Saudi Arabia, whether commercial, office, administrative, or educational, there exists a common problem that all architects face. This involves overcoming the difficulties posed by the extreme solar radiation and high temperatures. In the buildings of Riyadh, we find that the cooling of buildings plays a key role in total amount of energy consumption. This can be observed with the beginning of the era of modernity when designers became dependent on mechanical environmental control systems and moved away from the study of methodologies for energy conservation and experiences learned from the vernacular building typologies. There are two common sense strategies available but generally absent from 27 contemporary architectural practice: 1. to cover and protect the building by providing elements of shading, 2.to provide the use of alternative energy resources such as harvesting solar energy. For example: in hot arid environment such as Riyadh it is difficult to design a building without the use of thermal insulation in roofs and walls. This is noticeable in the thick masonry walls of early vernacular structures. Traditional buildings were often constructed of the material clay; we find that the wall is never less than 45 cm. This indicates the crucial need for the creation of a substantial insulation layer or thermal mass between the hot outside temperatures and the interior of the building. Fig. 2.1 Vernacular clay structures in Riyadh. The thick walls help to provide insulation from solar heat gain keeping the interior spaces cooler. Another example shows how the Nabateans used Greek forms and sculpted mountains in order to provide protection from the hot sun and try to adapt to the hot arid climate when they occupied the western region of the Arabian Peninsula. The resulting structures are a combination of the classical Greek architectural language with vernacular Arabic building practices. 28 Fig. 2.2 Qasr al-Farid, a Nabatean Tomb in Saudi Arabia combines Classical Greek elements with vernacular building practices. However, today we are seeing large numbers of openings or windows in buildings. Currently, most of the buildings that are designed do not take into account the proportion of openings to the proportion of the wall, or orientation towards the sun. Commercial buildings in Riyadh are designed without paying attention to the elements of shading or providing protection from the sun. Large amounts of glazing currently used results in high cooling energy loads. Additionally, glass facades are designed without taking into account sustainable practices such as using low-E glass or double glazing. Fig. 2.3 Contemporary high rise towers are designed to be completely dependent on mechanical cooling systems. The last point that must be noted is the high consumption of energy. We rely on feeding buildings in Saudi Arabia on one element only that is the electrical power produced by 29 oil. Cheap oil prices and state subsidies for oil in the uses of internal facilities and activities are the primary cause for the lack of initiative to explore alternative sources of energy. In Riyadh the amount of electrical energy used in a four-story building is the same as that of an eight story building (designed in the same manner) in a city with cooler temperatures as demonstrated in analyses run on EcoDesigner. Access to renewable forms of energy is very important as demonstrated in several research studies. All parts of the world have shown deep concern for the dependence on oil and an interest in the development of solar energy technology. The development of uses of renewable energy sources and how to make them economically feasible and available to all people is crucial when studying sustainable energy technology. In this regard, it is appropriate to study solar energy and its potential in the city of Riyadh and the surrounding villages, where electricity supply often experiences problems. How can these cells become the readily available to millions of people in this world in the event of scarcity of petroleum products? 2-2. Is using a sun tracking system important? One of the most important issues that have been studied is whether the photovoltaic system should follow the movement of the sun continuously. This is one of the most important strategic points pursued in this research. A compilation of studies was conducted in order to make sure that the system will work as proposed. One of the main issues targeted was to prevent the photovoltaic panels from shading their 30 neighbors in the southern façade of the building. The research consists of a series of studies concerning the pros and cons for the implementation of this system. “Will using a sun tracking system generates enough additional energy in order to compensate for the cost of the installation and operation of the system? (Perez Richard, 2004) 2-2-1. Disadvantages of the system Using a tracking systems will create a higher cost of installation, operation and maintenance. The primary reason for not using a tracking system is because of the project’s limited budget. To run the tracking system will consume large amounts of electric power in order to move the panels, and to change their orientation with different degrees of tilt as the path of the sun changes throughout the day. The additional energy that will be harvested from the tracking system will be used mostly to move and re-orient the panels. This appears to be the principal problem for implementation of the solar tracker. Through research studies it was found that most of the buildings that are designed based on animated elements have experienced repeated mechanical failures and are now non operational. For example, the Arab World Institute, Paris, France, built in 1980, a work of architect Jean Nouvel. The purpose of this system was to control the sun entering through the circular openings designed in the windows of the building in order to reduce glare inside the space. This is related to the unique use of the building, which contains a number of artifacts and exhibits that may be damaged from receiving direct sunlight. The system has been shut down after a period of experiencing problems with maintenance, cost, and the energy used to run 31 the sun sensors. From an environmental and economic viewpoint, many possible architectural solutions exist that may help to filter the individual rays of the sun without the use of mechanical systems. Fig. 2.4 The Arab World Institute’s façade is designed to adapt itself to the changing positions of the sun. 2-2-2. Advantages of the system Energy produced from elements tracking the sun was simulated using the program Photovoltaic Geographical Information System Orbiter. The results showed that the tracking system produces more energy than the fixed system by an increase of 29%. Using a tracking system can mean that the sun will remain blocked from the internal space of the building permanently. Implementing a tracking system in a responsive façade will continuously change the shape of the building, create a different shape at every moment and every surface, and give the building a very special architectural character. This creates a series of dynamic building forms that will change the appearance of the building throughout the year. The tracking system will cause the panels in the façade to rise in the summer to provide shading and to take advantage of the solar radiation. The 32 panels will eventually descend gradually to fit the movement of the sun in the fall and spring seasons and reach their lowest pitch is during the winter season in order to maximize the harvest of the sun’s rays into electrical energy. Fig. 2.5 Facade projection studies by Holder Mader & Alexander Stublic. The building grid is distorted according to a series of modifying parameters. 2-3. Preventing Self-Shading on the PV Panels The possibility of the panels casting shadows in each other creates a problem. A series of studies and simulations were conducted in order to generate a shape that would provide the maximum amount of projected surface area while preventing the photovoltaic panels from shading their neighbors. At latitude, 24 degrees North the sun lies directly above the earth's surface at noon on the summer solstice. This is the reason that using a horizontal design for the photovoltaic façade system will create shading on the bottom tiers of the panel, thus, lowering the amount of energy harvested. This creates a problem as shown in the image below; the louvers on the bottom portion are shaded, leaving only the upper row of louvers exposed to the sun. This is one of the issues that must be taken into account in order to create a scenario that will harvest the largest possible amount of solar energy for regions at 24 degree North Latitude. 33 Fig. 2.6 Diagram showing panels rotated at 90 degrees in order to block the perpendicular afternoon summer sun. In this case, in order to solve the problem, one has to thoroughly consider the degree of tilt and the distance between surfaces to allow this distance to have direct exposure to the sun. In the figure above, the louvers on the lower portion have no access to the sun. Installing solar panels on the bottom Louvers that are not exposed to the sun makes these panels useless and causes the owner or beneficiary high potential energy losses. 2-4. Shape and configuration The creation of the shape for the photovoltaic elements was a very arduous task. The purpose of the studies and simulations conducted was to access to a number of key points: First: maximizing the area of projection. Creating a large amount of projection area is of one of the biggest tasks for the researcher. The goal is to obtain the largest possible area without any shading on adjacent panels. Different shapes, while maintaining the 34 same length and width may contribute effectively to get more energy if we know that these forms of energy receive radiation from early hours of the morning until sunset. Second: generating the appropriate forms for the photovoltaic panels in order to respond to the movement of the sun. One of the challenges was to find three- dimensional forms responsive to the movement of the sun from sunrise until sunset. The final shape arrived at is one that takes advantage of the sun's rays on all sides east, west and south as well. The presence of larger areas exposed to sunlight gives a greater opportunity to benefit from the sun's energy and convert it to electrical energy. Fig. 2.7 Results of shadow studies on various shapes, pyramid, cube, and flat (Source: Archicad) For example, a spherical shape exposed to the sun throughout the entire day from the emergence of the sun until sundown results in the creation of shade on adjacent photovoltaic shapes. In these studies, the goal is to create a shape, which results in the largest amount of surface area without shading adjacent shapes in order to maximize the amount of solar energy being harvested. 35 Fig. 2.8 Diagram showing the solar exposure on panels throughout different times of the day for a spherical shaped panel. 2-5. Will the solar panel pay for itself? Solar energy is free and does not cost anything. However, the costs of equipment and installation are very expensive when compared to conventional electricity that is provided from local power plants. The estimated cost for installing a solar powered electric system can cost up to several million dollars. Due to high installation costs, the use of solar cells to generate electricity is most effectively used in places away from the local electricity grids, such as remote villages or spacecraft. (Crosby Kip, 2001) So far, the goal of a solar cell is to alleviate the energy burden on the building. Solar panels currently do not generally provide sufficient efficiency to fully operate all mechanical systems within a building. However, they can help to reduce energy consumption for cooling loads, space heating, or water heaters, and can greatly help to reduce the electrical load of the building. Although the scientific research conducted for the development of solar cells cannot produce electricity at a cost competitive with what is available from conventional sources of energy, the environmental advantages resulting from the using these sources of energy are pushing strongly in the direction of the use of solar cells. A rise in awareness for the environment has made solar energy one of the leading sources of innovative energy systems. 36 In the KACST project, one of the main concerns is that the energy gained would not be sufficient to provide for the high power demands that are necessary to run the building. In order to comply with the energy requirements of the building (to fully meet the energy demands or reduce the consumption of energy as much as possible), a series of questions were studied:  What are the best tilt angles in both vertical and horizontal planes?  How can shade elements be manipulated in order to not block the view?  Does the high heat of the sun affect the performance of photovoltaic panels? 2-6. Software Studies In various studies the use of a number of software for analysis and knowledge output is necessary. Studies so far have compared more than a dozen different programs in terms of use, purpose, and the information input and outputs. The multiplicity of different elements and functions in this research such as a study of energy produced the reduction of energy consumption in addition to natural lighting inside spaces and airflow when there is need for natural ventilation makes use of multiple programs a necessity. 37 Fig. 2.9 Diagram illustrating the purpose of the software programs used in the research 2-7. The Sun Angles Studies 2-7-1. ArchiCAD Analysis ArchiCAD is one of the early BIM programs, which has been highly developed in recent years. The advantage of this software is that it allows the user to easily create designs in 3d. The ArchiCAD program is produced in Germany by Graphicsoft. ArchiCAD is a well- known and popular in Europe. ArchiCAD is distinct in the analysis of the sun in different places and times in giving many choices for the position of the sun in different seasons 38 and in different regions. This program was chosen for two main goals: First, the studies of the shape, angles, and dimensions and, second, the study of energy using the Ecodesigner plug in. Fig. 2.10 Proposed pyramid panel façade modeled in Archicad. 2-7-2. Revit- Solar Radiation This program is similar to ArchiCAD in its command structure but differs in its graphics and icons. The main objective of entering this program is to plug in the solar radiation. The advantages of this program are the ease and speed in issuing the results compared to Ecotect. This program examines the solar radiation falling on surfaces (unit kW per square meter per year). However, when comparing the results of different programs we find a large difference in numerical results. 39 Fig. 2.11 Total yearly cumulative radiation cast on a single pyramid shaped panel, modeled and tested using Solar Radiation for Revit Architecture2011. 2-8. Solar Energy Generation 2-8-1. Photovoltaic Geographical Information System (PGIS) This program is a very important program for the prediction of the amount of energy that will be produced by solar panels. PGIS is a program with different characteristics and options. In this program location is selected via Google map identifying the longitude and latitude. In addition, the degree of tilt in both horizontal and vertical directions can be specified. This program also allows selection of the type of solar cell such as crystalline silicon, CIS or CdTe. The results appear in the form of a web page or PDF results including graphics and diagrams of energy production. 40 Fig. 2.12 PGIS plot showing the amount of solar radiation according in different region, the largest amount of radiation is shown in dark red, the least in light green. 2-8-2. PVCDROM This program is used to study the optimal angles for harvesting solar energy. The program has three parts; each is quite different in the idea and method of work. The advantage of this program is that it is easy to extract data. All of the studies were produced very quickly by simply moving the mouse to a certain degree of inclination or latitude chosen by the designer. The units for calculating the energy produced in this program are kilowatts per square meter per day. Fig. 2.13 Screenshot of PVCDROM showing the calculations for the optimal angle of inclination in solar panels to harvest the maximum amount of energy. 41 2-9. The Studies for Reducing Energy Consumption 2-9-1. EcoDesigner The program that I felt is accurate and simple to use is EcoDesigner. It calculates the impact of the surrounding buildings and trees. It also allows input of data generated during the drawing phase using Archicad. The program was developed so that you do not need to import an “epw” file into the program to select the region. In my opinion, it is a very helpful program to study energy optimization options in building design. This makes it much easier, if slightly less flexible. Fig. 2.14 Screenshot of EcoDesigner for Archicad showing the carbon footprint for the proposed building design of the Solar Village. 2-9-2. DesignBuilder The program was helpful in analyzing the energy consumption of the building, and allowing one to create an optimal design for energy efficiency. However, I found the program to be rather confusing. The program contains many details, many of which made little or no difference in the total results. For example, the details such as clothing type for summer and winter, and computer usage. The total energy consumption results 42 that I obtained from DesignBuilder seemed to fall in the middle of all the results that I obtained from other software. Fig. 2.15 Screenshot from DesignBuilder software showing the relationships between interior and exterior temperatures. 43 Chapter 3: Background 3-1. Preface This chapter focuses on the uses, components, and methods of installation that have been used in similar projects and can be applied to the KACST façade. The following strategies will be explored and applied in the creation of an environmentally sensitive façade: the use of photovoltaic cells to general solar power and the use of the photovoltaic system to act as sun breaker (louvers). 3-2. Photovoltaic cells Photovoltaic cells can produce electricity directly from sunlight in a clean way without creating negative impacts on the environment. Solar panels can be easily installed in non-intrusive manner without occupying any interior space within the building. Another advantage of photovoltaic cells is that they need little maintenance. A fixed PV system contains no moving parts, and can be installed and used without difficulty. Solar cells are made mainly of the material silicon (sand). The material is available on a large scale, and does not cause damage to the environment. The cells are grouped into larger aggregations and are quick to install. When grouped into modules PV systems can be quickly applied to cover an entire façade. The PV modules generate electricity at the point of use so there is no significant loss in electrical conductivity to and from a central plant. 44 Photovoltaic cells can be manufactured in various shapes, colors, and different specifications to suit special applications in buildings without affecting the character of architecture. Photovoltaic cells can also be manufactured in different levels of transparencies, ranging from transparent to opaque. This allows them to be used instead of ordinary window glass while allowing the partial penetration of natural daylight. Additionally, they can be manufactured in different colors, such as gray, brown, black, and green or in mixed colors. Some types of cells act as flexible wrap to fit into curved and circular surfaces. Solar cells can harvest direct sunlight in addition to the light reflected from surrounding surfaces to generate electricity. This allows the panels to work even if the sky is cloudy, contrary to the common misconception that these cells work only when the sun is shining and the sky is clear. During the night when the sun has set, the photovoltaic cells stop working; therefore electricity generated during the day must be stored in batteries or the grid if it is needed during nighttime hours. PV systems can be installed in buildings in various ways, such as on the roof or exterior walls of the building. In addition, they can also function as shading devices or rain breakers. A number of fundamentals are of direct relevance in determining the success or failure of PV installations. These include: The basics are arranged on the following form: 1 - solar radiation. 2 - Installation of units and angles of inclination. 45 3 - Solar unit and their characteristics. 4 – The position of units in the site or building envelope. 3-3. Solar radiation Solar radiation is a general term for the electromagnetic radiation emitted by the sun. We can capture and convert solar radiation into useful forms of energy, such as heat and electricity, using a variety of technologies. The technical feasibility and economical operation of these technologies at a specific location depends on the available solar radiation or solar resource. (Solar Radiation Basics, 2011) Fig. 3.1 Map showing the amount of solar radiation throughout the world, highest amounts show in dark brown smallest in white. Note Saudi Arabia receives the largest amount of solar radiation in the earth. The Earth receives 174 petawatts (PW) of incoming solar radiation (insolation) at the upper atmosphere. Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans, and landmasses. The spectrum of solar light at the Earth's surface is mostly spread across the visible and near-infrared ranges with a small part in the near ultraviolet. Earth's land surface, oceans and atmosphere absorb solar radiation, and this raises their temperature. (Solar Energy, Wikipedia, 2001) 46 Fig. 3.2 Diagram showing the amount of solar radiation that is absorbed and reflected within the earth’s surface. 3-4. Angles of inclination Degree of tilt for harvesting solar power using panels is one of the most important variables in the collection of solar energy. Each region of latitude requires a different degree of inclination. Latitude Spring/Autumn angle Insolation on panel % of optimum Summer angle Insolation on panel % of optimum 25° 22.5 6.5 75% -1 7.3 75% 30° 27.5 6.4 75% 3.5 7.3 74% 35° 32.5 6.2 76% 8.0 7.3 73% 40° 37.5 6 76% 12.5 7.3 72% 45° 42.5 5.8 76% 17 7.2 71% 50° 47.5 5.5 76% 21.5 7.1 70% Table 3.1 showing the optimal angle of inclination for harvesting solar energy according to a region’s latitude. (Landay Charler R., 2010). Incident radiation on the PV module depends not only on the energy in the sunlight, but also on the angle between the unit and the sun. When the sun is perpendicular to the surface, energy produced is a maximum. This is one of the questions that have been 47 studied using a program that gives PVCDROM at the top of its potential energy is working to find the optimal angle of the units by subtracting the angle 90 of the fall of the sun, the tilt of the surfaces is the output of the process is the subtraction. For example: if the sun sets at 37 degrees in the sky, the best angle of inclination of the panel to get the highest amount of radiation is 90:-37:= 53: Fig. 3.3 Picture showing the relationship between the elevation angle of sun & angle of panel In other words, the power density will always be at its maximum when the PV module is perpendicular to the sun. However, as the angle between the sun and a fixed surface is continually changing, the power density on a fixed PV module is less than that of the incident sunlight. (S. Bowden and C.B, 2011) Fig. 3.4 Chart showing the total solar radiation on the flat surface over one year for various angles of tilt. 48 3-5. The Solar Unit and characteristics Photovoltaic cells convert sunlight directly into electricity by using semiconductor materials such as silicon. In general, the material constituents of these cells are thick crystalline materials such as silicon crystal. The function of these cells is to provide a form of renewable and clean energy, because they do not produce operational waste and contamination, they do not produce noise and they do not depend on non- renewable fuel sources. However, the primary installation cost is high when compared to other energy sources. One of the advantages of solar cells is that they can generate electricity continuously and directly. They are particularly useful in systems where they are linked to the capacity to store energy harvested during the day in batteries or in the grid. Fig. 3.5 Photograph of a typical photovoltaic panel. These cells differ in resource cost of production as in well as the efficiency of the photovoltaic cell itself to convert solar energy into electric energy. Some cells have efficiency of 20%, while others 17% depending on the type of cell, method of manufacturing, and installation. Depending on the method of connection these solar cells can produce hundreds of Watts of electricity. 49 Table.3.2 showing the amount of energy that can be harvested using different types of PV panels, SunPower panels have the highest energy efficiency. Batteries range from 12 volts (20 amp \ h) to 16 850 AMP \ hours (2 volts) and are designed to last from 8-15 - 18 - 20 years. These batteries work to store energy after transformation via voltage regulator, and then send the power to the inverter to be transformed from DC to AC. 3-6. The position of units in the site or building envelope The position and placement of the solar panels in the building requires a series of studies in order to determine the amount of energy that can be obtained. The different location (Latitude) of these units means that a different degree of inclination will result in a different amount of energy that will be obtained. These may be described in seven forms, namely: shading systems, rain screen systems, stick systems, unitized curtain walls, double skin façades, atria or canopies. Fig. 3.6 Diagram showing conventional methods which can be used to provide protection and insulation from solar heat gain. 50 The use of photovoltaic energy in the outer parts of the building is functional in buildings of different uses such as public buildings: office complexes, production buildings, shopping centers, schools, or private buildings and private buildings such as houses or gardens in the residential units (including balconies). These units replace traditional materials in new buildings and can help to provide a moderate year-round interior climate. Fig. 3.7 SIEEB Building exterior perspective. 3-7. Case Study 1 SIEEB Solar Energy-Efficient Building Year: 2006 Architect: Mario Cucinella Location: Beijing, China Building Type: Educational Size: 20,000 sq.meters. 51 Fig. 3.8 Sketch showing the concept for the photovoltaic terraces in the SIEBB building. Static is not a word that describes the Sino-Italian Ecological and Energy-Efficient Building (SIEEB) at Tsinghua University in Beijing. Designed to maximize passive solar capabilities and fitted with state-of-the-art active solar elements, the SIEEB is a dynamic energy-efficient oasis that optimizes its urban location with ecological considerations. Architect Mario Cucinella and the Milan Polytechnic conceptualized the structure to educate and showcase possibilities for energy- efficient building, particularly in regard to CO2 emissions. (Ali Kriscenski, 2007) Fig. 3.9 SIEEB Building exterior perspective. The project is collaboration between the Ministry for Environment and Territory of the Republic of Italy and the Ministry of Science and Technology of the People’s Republic of China. The SIEEB takes on a symmetric layout that opens towards the south with stepped exposures and a central courtyard. Integrated photovoltaic arrays shade terraces while capturing solar energy. Double glass 52 façades with horizontal sunshades create the building’s exposed exterior on the east and west. Pivoting glass louvers with reflective coating cover the exterior walls of the courtyard to regulate daylight and solar gain. The northern exposure is heavily insulated and mostly opaque to shield against cold winter winds. (Ali Kriscenski, 2007) Fig. 3.10 Exterior view of PV shaded terracing at SIEEB Over 1000 square meters of photovoltaic panels supply primary energy needs. With a focus on minimum CO2 emissions, the architects opted for gas engines with electric generators for supplemental energy. Recaptured heat is used for hot water, winter heating and combined with absorption chillers for cooling in summer. Conditioned air is dispersed via displacement ventilation and a radiant ceiling system enhances thermal comfort. Room temperatures and lighting are sensor-controlled to minimize energy use when rooms are vacant. (Ali Kriscenski, 2007) Fig. 3.11 SIEEB Building Section 53 3-8. Sun breakers UV rays can cause multiple damages, which are being accelerated by the erosion of the ozone layer. This has resulted in newly leaked massive amounts of ultraviolet radiation that are at noticeably higher levels than 40 years ago. The impact of ultraviolet radiation on the skin is now much stronger resulting in higher levels of skin cancer. Additionally, solar radiation can have a negative an impact on the eye. However, the sun’s rays provide many benefits to the human body throughout one’s daily life needs, for example: prevention of cancer, strengthening of bones, fighting depression, and in reducing blood pressure. (Heather Brannon, MD, 2007) 3-8-1. Natural breakers In earlier eras, we find that the trees have played a major role in the shading of buildings and breaking up direct sunlight inside the building. Certain species of trees can allow light to enter in a positive pass through trunks and leaves, which function in filtering sunlight before it reaches us. “Trees can serve a variety of functions ranging from environmental, structural, or aesthetic”. (Liisa Tyrväinen, 2005) 3-8-2. Environmental function Plants provide a significant contribution to the environmental development of cities. The non-existence or lack of numbers of plants in any area leads to a failure of ecological balance in that region and; role can be summarized in the following points:  Reducing pollution, where the plant is working to increase the proportion of oxygen in the atmosphere through the process of photosynthesis.  Improving the atmosphere through transpiration and improving the climate, plants lead to lowering the temperature, especially during the summer. 54  Contributing to absorb the sounds and provide noise reduction, especially in crowded places in cities and succession.  Reducing the phenomenon of desertification.  Providing protection of soil and reduce the problem of soil erosion.  protecting from strong winds. Fig. 3.12 Photograph of residential building showing how trees can be used to provide protection from the sun. 3-8-3. Structural Functions Some plants can provide structural functional, for example; planting a group of plants close together to form walls or fences. Using plant fences can help to provide sound insulation in parks or create division or separation within parts of garden from each other, or to block out unwanted views. In addition to identifying walkers and roads in the cultivation of plants, garden fences can be used to guide the visitor towards a specific point. 3-8-4. Coordinating of Aesthetic Properly designing trees and other plants is one of the most essential elements in creating beautiful cities, landscapes, public gardens, and parks. 55 3-8-5. Phenomenon of Desertification Trees are an important component in providing natural insulation to buildings by protecting them from direct sun exposure. However, in a desert climate such as Saudi Arabia designers have avoided the use of trees due to the lack of water. In hot desert climates, finding fresh drinking water has always been a great challenge. For decades, the Saudi state has been providing clean water by converting millions of gallons of seawater via desalination plants that remove salts and minerals from the ocean water. Affected areas of the desert experience great poverty in the natural resources of water, these areas lack the rivers and lakes, and this makes the process of planting trees big problem facing the residents in the formation of a normal life. Fig. 3.13 Date palms in the desert of Saudi Arabia. 3-9. Elements of shading in an earlier time in the region Mashrabia are the well-known building element in traditional architecture, fabricated from wood or gypsum with small holes. The surface is perforated so as to allow the passage of a proportion of the solar radiation and block the rest. The rate of blocking depends on the percentage of holes in this surface, and on the angle of incidence of the sun. Mashrabia can be very useful if properly designed, both for climate control and for other aspects of architectural design as lighting, architectural configuration, privacy, protection from intrusion and 56 theft, and protection from insects. Mashrabia are not mobile in most cases, but must be designed to have a selective effect without relying on an operator to open and close, so as to allow vision horizontally or at an angle towards the landscape. An important point is to allow entry of air when you open the glass, as well as to prevent direct rays penetrating during periods of hot summer. (Mashrabiya, Wikipedia, 2011) Fig. 3.14 Photograph of traditional Marshrabia screens in Riyadh. Differences and features of shading used at the present time compared to Mashrabia: First, the use of lightweight materials, with different thermal characteristics, such as aluminum or plastic. Secondly, flexibility of design, Louvers may be horizontal, vertical, perpendicular, or on the sides of the window parallel to the window. In addition, “angles of inclination may be selected in order to get an effective blocking of radiation or to get an effective view”. (Feeney John, 1974) Important aspects are ease of manufacturing, installation and maintenance, easy removal and installation of these elements at the site, in addition to the ease of cleaning and maintenance when needed. 57 3-10. Architectural elements of shading Openings are a major source of heat gain into the building, so one must study the factors that control the amount of access through the thermal vents. The sun’s angles are constantly changing from sunrise throughout the daylight hours. This movement in combination with the various changes in the sun’s relative inclination to the earth in different season raises an urgent question. During what times of the year should solar radiation be blocked via means or shading, and is there a time when solar radiation can be beneficial? 3-10-1. Means of Shading 1) The means of shading of exterior surfaces, which can be provided through the following methods: • Horizontal sun breakers: are most effective in north and south facing facades. • Vertical sun breakers are most effective in the eastern and western facades, usually in combination with horizontal elements. 2) The means of shading the interior. In some cases, the means of external shading are not enough to provide the desired protection from the sun. In such case, additional means of shading need to be added to the interior. Interior shading includes the following types: • Sliding systems • Folding systems 58 Exterior systems are preferable, since they stop heat gain outside the building, unlike interior shading, which absorbs some heat which remains inside the space. The building must be designed in a manner that reduces the need for fuel and electric power and pursues a greater reliance on natural energies. Ancient societies understood this principle and achieved it in many cases. In addition, many cities in ancient civilizations have taken into account the southern interfaces of the buildings. One of the most important principles in ancient civilization is the strategy of providing shade in both private space and public urban fabric. Shadow is one of the most important factors contributing to reduction of total energy consumption in addition to providing aesthetic qualities. The difference between sunny and shaded areas can be responsible for providing visual beauty to buildings as a result of refraction or surface visibility. The presence and prevalence of shadow elements can add to the architectural character of a city. Architectural elements, such as fixed or portable shading devices or building openings, are used to control the passage of light into the man-made environment. These elements can be made of different materials such as aluminum, wood, fiberglass, and concrete. Fig. 3.15 Photograph of fixed horizontal louvers applied to a building façade in order to provide protection from the sun. 59 The west façade is the most difficult interface for thermal treatment and solar protection. This is because western facades are exposed to direct sunlight coming at low angles at the hottest time of the day. The angles of the sun create a difficult situation in designing shading devices which allow a view to the exterior while simultaneously providing protection from the sun. At this interface it is possible to increase the thickness of the wall or use of double walls, between which there is an insulation layer; however, the use of solid walls does not allow for views outside. The best way to provide solar protection for the western façade is to use architectural sun breakers programmed to move with the sun angles. Protection from the rays of the sun in the western facades can be achieved by the following methods: using vertical fins, which extend from floor to ceiling or provision of operable sun breakers that can be re-positioned so to provide shade in relation to the different sun angles throughout the day. Fig. 3.16 Photograph showing vertical fins applied to a buildings western façade to provide protection from solar heat gain. 60 Exposed southern facades receive direct sunlight in the middle of the day during the hot summer months. The best means to address this interface is through the use of horizontal fixed or mobile sun breakers, or balconies and terraces. Protection from the rays of the sun in the southern facades can be achieved in the following ways:  Provide protection of the southern facade through horizontal overhangs.  Protection can be provided though horizontal louvers which may be fixed or mobile. 3-11. How can sun breakers manipulate airflow? Airflow inside a space can be manipulated through the design of the louvers on the exterior skin though variations in the tilt angles, size, and distances between the panels. These elements can be designed to allow the entry of light and heat in the winter and prevent the sun from entering in the summer. Additionally, they can help to reduce energy consumption in other ways, such as allowing for natural day lighting, flow of air inside the space and natural ventilation. Breath is life, and if the process of breathing itself is the basic process of the survival of organisms. The quality of the air we breathe is as important as the process itself, breathing air that contains contaminants has caused major problems even for otherwise healthy people. The problem of indoor air pollution has been exacerbated during the last decades of the twentieth century with the increased use of harmful building materials, finishes, and chemicals. Harmful materials in combination with the fact that modern buildings are sealed so as not to 61 allow any leakage of air to control the operations of heating or cooling and to increase efficiency has resulted in very poor indoor air quality. Providing good ventilation in buildings is considered one of the most important factors to overcome the concentration of pollutants. In order to provide good ventilation, the designer must take special care in directing building openings to the prevailing wind direction of each region. Multiple openings as well as openings on the opposing façade must be created in each room in order to create the proper airflow (cross ventilation). Fig. 3.17 Metal horizontal louvers at Burj Khalifah 3-12. Case Study Burj Khalifah, Dubai. Burj Khalifah is located in Dubai, United Arab Emirates. The Tower is the tallest tower in the world at height of 828 meters. Construction began in the September 21, 2004 and finished in October 2009. The building formally opened on January 4, 2010, to become the world's tallest building. This building contains different uses: residential, commercial, and entertainment; all of which use architectural design strategies in order to control the climate in sustainable ways. The designer Adrian Smith considered all environmental design solutions 62 that may help in reducing the enormous energy consumption in the building. (Smith Adrian Devaun, 2007) In this project, the louvers on the lower floor are designed to protect interior space from the sun. This was done by studying the depth of the panels in relationship to the latitude of the city of Dubai. The configuration and size of louvers vary from one location and/or use to another, and this is shows the care used by the designer in dealing with these elements. The louvers in the offices floors are designed to work in two main ways: first, to prevent the sun’s rays from directly entering the interior spaces, second by harvesting the sun’s energy through the PV panels placed on the louvers. Fig. 3.18 Photograph showing photovoltaic panels applied to the horizontal louvers at Burj Khalifah . Fig.3-19 Section detail of horizontal overhangs at Burj Khalifah 63 Chapter 4: Data 4-1. Introduction Data was collected from two separate studies conducted using the software program Solar Radiation for Revit Architecture. The first study consists of a series of simulations and documentation the results for flat shape and pyramid panels (25cm, 35cm, and 45 cm) based on the amount of solar radiation that is received per square meter. Due to the varying projection angles in the flat and pyramid shapes, the amount of radiation received was different at each instance. When compared to the flat shape panel, the pyramid panel received a larger amount of yearly solar radiation.  Flat shape: (1390 KWh at 0:, 510 KWh at 90 0 , 970 KWh at 24 0 , 1300 KWh at 47 0 )  25 cm pyramid: (1234 KWh at 0:, 780 KWh at 90 0 , 1406 KWh at 24 0 , 1354 KWh at 47 0 )  35 cm pyramid: (1180 KWh at 0:, 830 KWh at 90 0 , 1382 KWh at 24 0 , 1380 KWh at 47 0 )  45 cm pyramid: (1062 KWh at 0:, 930 KWh at 90 0 , 1302 KWh at 24 0 , 1344 KWh at 47 0 ) In the second phase of the study, the total projection area was calculated for each unit. The results demonstrate that by using a pyramid shape a larger projection area is achieved within the same perimeter, 2m 2 . For the flat shape, the total projection area was 2m 2 , for a 25cm pyramid 2.13m 2 , for a 35cm pyramid 2.26 m 2 , and for a 45cm 64 pyramid 2.39 cm 2 . The greater the depth of the pyramid the larger the amount of projection area obtained. Thusly, the largest amount of radiation was achieved by using a 45cm deep pyramid at an inclination of 47 0 . The results for the total radiation obtained per unit were as follows:  Flat shape (2m 2 ) : (1390 KWh at 0:, 510 KWh at 90 0 , 970 KWh at 24 0 , 1300 KWh at 47 0 )  25 cm pyramid (2.13m 2 ): (1314.21 KWh at 0:, 830.7 KWh at 90 0 , 1497.39 KWh at 24 0 , 1442.01 KWh at 47 0 )  35 cm pyramid (2.26m 2 ): (1256.7 KWh at 0:, 883.95 KWh at 90 0 , 1471.83 KWh at 24 0 , 1469 KWh at 47 0 )  45 cm pyramid (2.39m 2 ): (1274.4 KWh at 0:, 1116 KWh at 90 0 , 1562.4 KWh at 24 0 , 1612.8 KWh at 47 0 ) However, when the panels are arrayed along the building façade, the 45 cm shape will cast shadows on neighboring units. This prevents the panels from receiving the optimal amount of radiation. A series of studies was conducted using Ecotect software in order to determine the optimal depth at which the panels did not shade adjacent units. The results showed that the 35cm pyramid provides the largest amount of possible surface area without blocking sunlight on neighbors. Therefore, the 35 cm pyramid at a tilt angle of 24 0 was chosen as the optimal shape for the solar panels that will compose the new adaptive building skin. 65 Fig.4-1. Shadow studies on panel arrays for June 21, September 21, and December 21. (Source: Ecotect) 4-2. Solar Radiation at specified positions Fig.4-2. 3D model of panels modeled in Revit Architecture. 4-2-1. Comparison of the solar radiation between the flat shape and the pyramid with 25cm depth: A series of calculations were performed testing two different shapes of the same length and width (flat shape and pyramid at 25 cm depth). The shapes were divided into four equal faces. The shapes were tested at four different degrees of tilt; the total amount of solar radiation projected on each face was recorded. The degrees of tilt were chosen for the following reasons: 0 ● ° : The optimal degree for summer solstice at a latitude of 24° . ● 90° : The degree that will receive the least amount of solar energy. ● 24° : The optimal degree for receiving solar energy throughout the year. ● 47° : The optimal degree for winter solstice at latitude of 24 ° 66 The results showed that the pyramid shape received a larger amount of solar energy versus the flat shape.  At 0° the pyramid will receive energy 2815 KWh/2 m 2 /year , the flat shape will receive 2780 KWh/2 m 2 /year.  At 90° the pyramid will receive energy 1156 KWh/2 m 2 /year , the flat shape will receive 1020 KWh/2 m 2 /year.  At 24° the pyramid will receive energy 2899 KWh/2 m 2 /year , the flat shape will receive 2860 KWh/2 m 2 /year.  At 47° the pyramid will receive energy 2543 KWh/2 m 2 /year , the flat shape will receive 2600 KWh/2 m 2 /year  Solar Radiation KWh/Unit/year Table.4-1. Total Yearly Radiation on 25 cm pyramid Fig.4-3. Diagram showing pyramid shaped panel divided into four equal faces. Table.4-2. Total Amount of Radiation Obtained Energy 0 Degree 90 Degree 24 Degree 47 Degree Flat Panel Total 0 8 7 0 0 0 0 0 0 7 8 0 0 8 0 0 Pyramid Panel Total 0 7 0 5 1 7 8 0 0 5 8 1 5 1 0 7 1 7 1 1 2 0 5 . 2 1 0 0 67 Fig.4-4. Chart Comparing Radiation obtained in flat panels versus 25cm pyramid panel. 4-2-2. Comparison of the solar radiation between the flat shape and the two-faced pyramid with 25cm depth Fig.4-5. 3D model of panels top sides only modeled in Revit Architecture. A second series of calculations were performed in which the bottom faces were removed in order to allow for light and air to flow into the interior spaces of the buildings. Faces 1 and 2 of the pyramid and flat shapes were tested under the same degrees of tilt; the total amount of solar radiation on each face was recorded. The results showed that the pyramid shape received a larger amount of solar energy versus the flat shape. 68  At 0° the pyramid will receive energy 1314 KWh/m 2 /year , the flat shape will receive 1390 KWh/m 2 /year.  At 90° the pyramid will receive energy 830 KWh/m 2 /year , the flat shape will receive 510 KWh/m 2 /year.  At 24° the pyramid will receive energy 1497 KWh/m 2 /year , the flat shape will receive 1430 KWh/m 2 /year.  At 47° the pyramid will receive energy 1442 KWh/m 2 /year , the flat shape will receive 1300 KWh/m 2 /year. Solar Radiation KWh/Unit/year Table.4-3Total Yearly Radiation on 25 cm pyramid Fig.4-6. Diagram showing pyramid shaped panel divided into two equal faces. Table.4-4. Total Amount of Radiation Obtained ygrenE 0 Degree 90 Degree 24 Degree 47 Degree Flat Panel Total 0 2 1 0 5 0 0 0 . 2 0 0 2 0 0 Pyramid Panel Total 0 2 0 . 1 0 0 7 2 0 18 0 . 1 8 1 2 1 0 . . 0 1 0 0 69 Fig.4-7. Chart Comparing Radiation obtained in flat panels versus 25cm pyramid panel. 4-2-3. Comparison of the solar radiation between the flat shape and the pyramid with 35cm depth Fig.4-8. 3D model of panels modeled in Revit Architecture. A third series of calculations were performed testing two different shapes of the same length and width (flat shape and pyramid at 35 cm depth). The shapes were divided into four equal faces. The shapes were tested at four different degrees of tilt; the total amount of solar radiation projected on each face was recorded. The degrees of tilt were chosen for the following reasons: 70 The results showed that the pyramid shape received a larger amount of solar energy versus the flat shape.  At 0° the pyramid will receive energy 2915 KWh/2 m 2 /year , the flat shape will receive 2780 KWh/2 m 2 /year.  At 90° the pyramid will receive energy 1254 KWh/2 m 2 /year , the flat shape will receive 1020 KWh/2 m 2 /year.  At 24° the pyramid will receive energy 3010 KWh/2 m 2 /year , the flat shape will receive 2860 KWh/2 m 2 /year.  At 47° the pyramid will receive energy 2734 KWh/2 m 2 /year , the flat shape will receive 2600 KWh/2 m 2 /year. Solar Radiation KWh/Unit/year Table.4-5. Total Yearly Radiation on 35 cm pyramid Fig.4-9. Diagram showing pyramid shaped panel divided into four equal faces. Table.4-6. Total Amount of Radiation Obtained Energy 0 Degree 90 Degree 24 Degree 47 Degree Flat Panel Total 0 8 7 0 0 0 0 0 0 7 8 0 0 8 0 0 Pyramid Panel Total 0 1 0 5 1 . 0 0 5 . 1 2 2 0 0 0 1 2 0 0 8 2 . 1 8 71 Fig.4-10. Chart Comparing Radiation obtained in flat panels versus 35cm pyramid panel. 4-2-4. Comparison of the solar radiation between the flat shape and the two-faced pyramid with 35cm depth Fig.4-11. 3D model of panels modeled in Revit Architecture. A fourth series of calculations were performed in which the bottom faces were removed for the flat shape and pyramid at 35 cm depth. Faces 1 and 2 of the pyramid and flat shapes were tested under the same degrees of tilt; the total amount of solar radiation projected on each face was recorded. The results showed that the pyramid shape received a larger amount of solar energy versus the flat shape. 72  At 0° the pyramid will receive energy 1256 KWh/m 2 /year , the flat shape will receive 1390 KWh/m 2 /year.  At 90° the pyramid will receive energy 883 KWh/m 2 /year , the flat shape will receive 510 KWh/m 2 /year.  At 24° the pyramid will receive energy 1471 KWh/m 2 /year , the flat shape will receive 1430 KWh/m 2 /year.  At 47° the pyramid will receive energy 1469 KWh/m 2 /year , the flat shape will receive 1300 KWh/m 2 /year. Solar Radiation KWh/Unit/year Table.4-7. Total Yearly Radiation on 35cm pyramid. Fig.4-12. Diagram showing pyramid shaped panel divided into two equal faces. ygrenE 0 Degree 90 Degree 24 Degree 47 Degree Flat Panel Total 0 2 1 0 5 0 0 0 . 2 0 0 2 0 0 Pyramid Panel Total 0 0 5 8 1 8 7 7 2 11 5 0 . 8 0 1 7 2 0 . 8 1 1 8 Table.4-8. Total Amount of Radiation Obtained 73 Fig.4-13. Chart Comparing Radiation obtained in flat panels versus 35cm pyramid panel. 4-2-5. Comparison of the solar radiation between the flat shape and the pyramid with 45cm depth Fig.4-14. 3D model of panels modeled in Revit Architecture. A fifth series of calculations were performed testing two different shapes of the same length and width (flat shape and pyramid at 45 cm depth). The shapes were divided into four equal faces. The shapes were tested at four different degrees of tilt; the total amount of solar radiation projected on each face was recorded. The degrees of tilt were chosen for the following reasons: 74 The results showed that the pyramid shape received a larger amount of solar energy versus the flat shape.  At 0° the pyramid will receive energy 0 7 7 .KWh/m 2 /year , the flat shape will receive 1390 KWh/m 2 /year.  At 90° the pyramid will receive energy 0 2 8 7KWh/m 2 /year , the flat shape will receive 510 KWh/m 2 /year.  At 24° the pyramid will receive energy 0 1 8 . KWh/m 2 /year , the flat shape will receive 1430 KWh/m 2 /year.  At 47° the pyramid will receive energy 0 8 0 7KWh/m 2 /year , the flat shape will receive 1300 KWh/m 2 /year Solar Radiation KWh/Unit/year Table.4-9. Total Yearly Radiation on 45 cm pyramid Fig.4-15. Diagram showing pyramid shaped panel divided into four equal faces. Energy 0 Degree 90 Degree 24 Degree 47 Degree Flat Panel Total 0 8 7 0 0 0 0 0 0 7 8 0 0 8 0 0 Pyramid Panel Total 0 7 7 . 1 7 0 2 8 7 0 1 8 . 0 8 0 7 Table.4-10. Total Amount of Radiation Obtained 75 Fig.4-16. Chart Comparing Radiation obtained in flat panels versus 45cm pyramid panel. 4-2-6. Comparison of the solar radiation between the flat shape and the two-faced pyramid with 45cm depth Fig.4-17. 3D model of panels modeled in Revit Architecture. A sixth series of calculations were performed in which the bottom faces were removed in order to allow for light and air to flow into the interior spaces of the buildings. Faces 1 and 2 of the pyramid and flat shapes were tested under the same degrees of tilt; the 76 total amount of solar radiation on each face was recorded. The results showed that the pyramid shape received a larger amount of solar energy versus the flat shape.  At 0° the pyramid will receive energy 0 0 8 .KWh/m 2 /year , the flat shape will receive 1390 KWh/m 2 /year.  At 90° the pyramid will receive energy 0 0 0 8 KWh/m 2 /year , the flat shape will receive 510 KWh/m 2 /year.  At 24° the pyramid will receive energy 0 5 8 0KWh/m 2 /year , the flat shape will receive 1430 KWh/m 2 /year.  At 47 the pyramid will receive energy 0 8 0 0KWh/m 2 /year , the flat shape will receive 1300 KWh/m 2 /year. Solar Radiation KWh/Unit/year Table.4-11. Total Yearly Radiation on 45 cm pyramid Fig.4-18. Diagram showing pyramid shaped panel divided into two equal faces. 0 Degree 90 Degree 24 Degree 47 Degree Flat Panel Total 0 2 1 0 5 0 0 0 . 2 0 0 2 0 0 Pyramid Panel Total 0 0 8 . 1 . 0 0 0 8 0 5 8 0 1 . 0 8 0 0 1 7 Table.4-12. Total Amount of Radiation Obtained 77 Fig.4-19. Chart Comparing Radiation obtained in flat panels versus 45cm pyramid panel. 4-3. Calculating the solar radiation using Photovoltaic Geographical Information System PGIS One of the web-sites that were most useful in this study phase is PGIS. This site allows researchers multiple options in terms of site selection, inclination angles and slope in addition to examining tracking of the sun. This site is intended to support physics research; unfortunately, it is not possible to insert or include any particular form except for flat surfaces. For that reason it was necessary to divide the pyramid shapes into four equal flat faces in order to calculate the radiation received on each face and to allow for variation in the angle of tilt by tilting the four individual faces. After devising this solution we attempted to calculate two forms to compare the PGIS numbers with those that were calculated by Revit Solar Radiation and to test whether results were consistent. 78 Flat 0 Degree All sides Side 1 Side 2 Side 3 Side 4 Side 1 Side 2 Side 3 Side 4 Side 1 Side 2 Side 3 Side 4 Tilt 0 352 352 8 8 346 346 14 14 340 340 20 20 Azimuth 0 8 -8 8 -8 14 -14 14 -14 20 -20 20 -20 90 Degree Tilt 90 82 82 98 98 76 76 104 104 70 70 110 110 Azimuth 0 8 -8 8 -8 14 -14 14 -14 20 -20 20 -20 24 Degree Tilt 24 16 16 32 32 10 10 38 38 4 4 44 44 Azimuth 0 8 -8 8 -8 14 -14 14 -14 20 -20 20 -20 47 Degree Tilt 47 39 39 55 55 33 33 61 61 27 27 67 67 Azimuth 0 8 -8 8 -8 14 -14 14 -14 20 -20 20 -20 35cm 45cm 25cm Fig.4-20. Picture shows the division that has made for the 25cm pyramid panel to be able to study in PGIS. Table.4-13. Table shows the angles of inclination and azimuth of each pyramid 4-3-1. Calculating the solar radiation for the flat surface using PGIS This phase was complex, because the large number of numeric analyses that were required to make sure of inclination and azimuth angles because each shape has four different faces and every face has its own angles of inclination and azimuth. Flat surfaces were easier to examine since all faces had the same tilt angle. 79 Table.4-14. Total Amount of Radiation Obtained at different tilt angles; Left at 0° Right at 90° Table.4-15. Total Amount of Radiation Obtained at different tilt angles; Left at 24° Right at 47° . Amounts of energy received were different with different tilt angles; with the largest amounts received at the tilt angle of 24 degrees (which is the optimal angle for latitude 80 24° .) Outcomes were uneven and differed from the Revit Solar Radiation results in a number of cases. For example: using this web site we find that the results at angle of tilt zero are equal to to at 47° , which is quite different from the output of Revit Solar Radiation.  At 0° the flat surface will receive energy 1350 KWh/m 2 /year.  At 90° the flat shape will receive 535 KWh/m 2 /year.  At 24° the flat shape will receive 1450 KWh/m 2 /year.  At 47° the flat shape will receive 1350 KWh/m 2 /year. 4-3-2. Calculating the solar radiation for the 25cm pyramid at 24⁰ using PGIS In this section the focus was on the optimum angle for Riyadh city which is 24 degrees. Because the purpose of this calculation was only to compare results we chose a single case which was taken to be the 25 cm depth pyramid with a 24˚ angle of tilt. This case will be taken as representative; other pyramids and tilt angles will be detailed in the Appendix. 81 Table.4-16. Total Amount of radiation Obtained at different tilt angles; Left at 16° inclination and 8° azimuth (face1); Right at 16° inclination and -8° azimuth (face2). Table.4-17. Total Amount of radiation Obtained at different tilt angles; Left at 32° inclination and 8° azimuth (face 3); Right at 32° inclination and -8° azimuth (face 4)  Face 1 At 16° tilt and 8° azimuth the surface will receive energy 1470 KWh/m 2 /year. 82  Face 2 At 16° tilt and -8° azimuth the surface will receive energy 1470 KWh/m 2 /year.  Face 3 At 32° tilt and 8° azimuth the surface will receive energy 1390 KWh/m 2 /year.  Face 4 At 32° tilt and -8° azimuth the surface will receive energy 1390 KWh/m 2 /year. Table Keys Ed: Average daily electricity production from the given system (KWh). Em: Average monthly electricity production from the given system (KWh). Hd: Average daily sum of global irradiation per square meter received by the modules of the given system (KWh/m2). Hm: Average sum of global irradiation per square meter received by the modules of the given system (KWh/m2). 83 Chapter 5: The Module and the Array 5-1. Introduction This chapter addresses the process through which the individual pyramidal module and the array of modules were developed and refined. 5-2. Maximize sun exposure on surface area and how this will reflect in the projection area One clear target of the development is to provide the largest possible area exposed to the sun in view of the limited surface area of the façade. Table 5-1. Describing the differences in surface area between the flat surface and three pyramids with different depths. 5-2-1. Using the four faces of the pyramid for photovoltaics on the southern faç ade The module’s surface area is directly correlated with energy production; the greater the area exposed to sunlight the greater will be the electrical power produced by photovoltaic, and the converse is true. The existing southern façade is only 70 meters in 84 length and 18 meters in height; this provides only 1260 square meters from which to generate energy. Fig.5-1. 3D model of panels modeled in Revit Architecture. Total energy received by the south Façade (KWh/yr) 0 Degree 90 Degree 24 Degree 47 Degree Flat panle 1041511 256211 1011011 1200111 Pyramid 25cm Depth 1000541 060601 1064051 1216161 Pyramid 35cm Depth 1002016 061616 1062416 1066060 Pyramid 45cm Depth 1010565 021051 1020061 1244251 Table5-2. Total Yearly Radiation on flat, 25 cm, 35cm and 45cm pyramids at various tilt angles Fig.5-2. Total Yearly Radiation on arrays of flat, 25 cm, 35cm and 45cm pyramids for various tilt angles  At 0° the pyramid with 35 cm depth will receive the highest amount of energy in comparison with the other geometries. 85  At 90° the 45 cm depth pyramid will receive the highest amount of energy (021051 KWh/year.)  At 24° the 35cm pyramid will receive the highest amount of energy (1062416 KWh/ year.)  At 47° also the 35 cm pyramid will receive the highest amount of energy. In this phase of the research we discovered that the shape of the pyramid with depth of 35 cm receives the highest amount of energy, by comparing this with the rest of the other geometries. This analysis has been carried out for several different tilt angles as mentioned in chapter four. The 45 cm depth pyramid receives the highest amount of energy only for an inclination of 90 degree, but this is of little importance since at that angle very little solar radiation reaches the panels. It is notable that the amount of energy received by the array is large. King Abdul-Aziz City for Science and Technology will not rely on renewable energy at this time as main energy source, but this renewable energy will play an important part in reducing demand for external electric power. Fig.5-3. Picture shows the difference of projection area between the four different shapes. 86 5-2-2. Using two top faces of the pyramid for photovoltaics on the southern faç ade In this case, the existing southern façade (70 meters in length and 18 meters in height) provides only 630 square meters from which to generate energy; solar panels cover only 50% of the façade. Fig.5-4. 3D model of panels modeled in Revit Architecture. Total energy received by the south Façade (half surface area) (KWh/year) 0 Degree 90 Degree 24 Degree 47 Degree Flat Panels 004011 061011 211111 016111 Pyramid 25cm Depth 060646.0 460051 650111 610521 Pyramid 35cm Depth 061061 442000.4 660646.6 664611 Pyramid 45cm Depth 016006 010101 605016 1112125 Table5-3. Total Yearly Radiation received on two sides of flat, 25 cm, 35cm and 45cm pyramids for various tilt angles Fig.5-5. Total Yearly Radiation received on two sides of flat, 25 cm, 35cm and 45cm pyramids for various tilt angles 87  At 0° the flat panel will receive the highest amount of energy.  At 90° the 45 cm depth pyramid will receive the highest amount of energy (010101KWh/year.)  At 24° the 45cm pyramid will receive the highest amount of energy (605016KWh/ year.)  At 47° also the 45 cm pyramid will receive the highest amount of energy. 5-2-3. Solar Radiation on panels rotated toward the west at different angles To maximize the amount of solar exposure on the surface of the panels a study was conducted in which the panels were rotated toward the west. By providing increased western exposure, the photovoltaic cells are be able to receive more direct radiation as the sun angles move diagonally. Both flat and pyramid shapes were calculated using Solar Radiation for Revit at four different degrees of rotation: 12 o W, 24 o W, 36 o W , and 44 o W . The results were as following:  Flat Panel (4 Sides): 14.24 KWh/unit at 0 o , 28.72 KWh/unit at 12 o , 29.76 KWh/unit at 24 o , 30.72 KWh/unit at 36 o , and 31.21 KWh/unit at 44 o  Pyramid (4 Sides): 15.16 KWh/unit at 0 o , 30.08 KWh/unit at 12 o , 31.38 KWh/unit at 24 o , 32.45 KWh/unit at 36 o , 33.82 KWh/unit at 44 o .  Flat Panel (2 Sides): 7.12 KWh/unit at 0 o , 14.36 KWh/unit at 12 o , 14.88 KWh/unit at 24 o , 15.36 KWh/unit at 36 o , 15.76 KWh/unit at 44 o . 88  Pyramid (2 Sides): 8.93 KWh/unit at 0 o , 17.44 KWh/unit at 12 o , 17.84 KWh/unit at 24 o , 18.26 KWh/unit at 36 o , 18.75 KWh/unit at 44 o . These simulations show that as the panels are increasingly rotated towards the west, the amount of energy received becomes greater. In comparison to the south facing position when the photovoltaic panels are rotated at 36˚ West the amount of solar radiation that they receive more than doubles. Rotating the panels towards the west provides the opportunity to harvest twice the amount of energy. In addition this rotation will also help to increase shade in the interior office spaces during the afternoon hours, reducing the energy needed for air conditioning. 5-2-4. Solar Radiation on four-faced panels rotated at different angles to west South 12o to West 24o to West 36o to West 44o to West The Pyramid 15.1646 30.0806 31.3801 32.4536 33.82 The Flat 14.24 28.72 29.76 30.72 2 0 10 0 Table5-4. Total Yearly Radiation of flat and 25 cm pyramids tilt to the west Fig.5-6. Total Yearly Radiation rotated at different angles to west 89 Fig.5-7. Rotating the panels with four faces from the south toward the west (from the left: 0 o , 12 o , 24 o , 36 o , 44 o ). 5-2-5. Solar Radiation on two-faced panels rotated at different angles to west: South 12o to West 24o to West 36o to West 44o to West The Pyramid 8.93985 17.441 17.8476 18.2649 18.7532 The Flat 7.12 14.36 14.88 15.36 15.76 Table5-5. Total Yearly Radiation of two faces of flat and 25 cm pyramids rotated toward the west Fig.5-8. Total Yearly Radiation received by two-faces rotated at different angles toward the west Fig.5-9. Rotating the two top faces of the panels from the south toward the west (from the left: 0 o , 12 o , 24 o , 36 o , 44 o ) 90 5-3. Determination of the final form An optimal form had to be decided upon in order to reach the main objective of this research. In view of all the alternatives studied the shape of pyramid was chosen with a 25cm depth and an inclination angle of 24:. The 25cm pyramid will be somewhat less expensive than steeper pyramids because its surface area is smaller. Although the 45 cm pyramid receives somewhat more energy per module it was found to have disadvantages in terms of shading neighboring modules. In term in numbers the 25cm pyramid will give more energy by 35% with when compared with the flat surface, 2% more when compared with the 35cm pyramid, and 4% less by comparison with 45cm pyramid, as shown in the following table; Total Energy 42 Degree Flat Two Faces only KWh/year 800000 Pyramid 25cm Depth Two Faces only KWh/year 1.2000 Pyramid 25 cm Depth Two Faces only KWh/year 1080 501 1 Pyramid .5 cm Depth Two Faces only KWh/year 17.200 Table.5-6. Total Yearly Radiation just the two top faces of the 25cm Pyramid at 24⁰ Fig.5-10. Total Yearly Radiation just the two top faces of the 25cm Pyramid at 24⁰ tilt angle 91 Fig.5-11. The final form of the unit with description of each part. 92 Chapter 6: The effects of the shading system on the building and the users 6-1. Reducing the annual energy consumption The goal of the King Abdul-Aziz City for Science is to provide an optimal model for the development of the country, and to keep current with and participate in developments in every scientific filed; to recruit all the findings of the human mind to raise the quality of life. The Kingdom of Saudi Arabia as a developing country is working to keep up with progress and development that serves its people. It is making use of current intellectual and scientific developments and intending to actively participate in findings conducted in other countries, scientific research centers, and universities. On this basis, the government of the Kingdom of Saudi Arabia aims to provide buildings for research as well as to simultaneously create a built environment that is sensitive to local climatic conditions and concurrent with advanced building practices. It is important to create an architecture and urban environment suited to the desert climate in order to help to reduce construction and maintenance costs. Therefore the primary topic of this study: “to reduce energy loads and reduce the annual cost of electric power.” In this research, the most important goal was to reduce the power consumption of the building. This dilemma is faced by all people in Saudi society, whether designers or client. In this building, the energy reduction that has been achieved is not very great, but this is partly due to the limitation of adding solar 93 screening elements only to the southern facade of the building. The building as designed consumes 808547KWh/year. This number is not very large because the building is used only for a limited time per day and by limited staff. Adding the screening system to the South façade of the building has reduced energy consumption to758500 KWh/year, a reduction of approximately 6.19% of the actual consumption of the building. Reducing the annual consumption of electrical energy produces many benefits: the most important is the reduction of the carbon production of the building, which was reduced from 392 tons to 366 tons per year as is shown in the following figure: Fig.6-1. The annual energy consumption of the building; Left is building as designed, Right is the energy by adding the shading elements in the south façade. 94 6-2. Does not cause shading on neighboring modules One of the important issues in this research was whether the modules in these panels will shade each other? We made a number of studies which investigate whether the modules shade each other. One study examined three days : June 21, September 21 and December 21 (these days are the beginning of seasons.) This study was made using Ecotect, which was very convenient for determining shadow angles. That was not quite enough to provide convincing validity so a second study was undertaken by making a cardboard physical model and testing it. Fig.6-2. Examine shade and shadow on the panels for June 21 (Ecotect) Fig.6-3. Study shade and shadow on the panels for September 21 (Ecotect) 95 Fig.6-4. Observe the shade and shadow on the panels for December 21 (Ecotect). 6-3. To fit the panels to the faç ade Fitting the shape in the façade took a large effort in the course of the study; partly because of the commitment of the client to a particular form. In the study for approval of the shape several different types of geometries were explored such as circular and polygons. The number of geometric shapes available to be investigated is limitless; these forms differ in the angles as well as in the number of ribs and surfaces. Examining alternate geometric shapes requires a full understanding and comprehension of angles and surfaces, as well as the relations between neighboring shapes. We limited our investigation to three different forms: the pyramid, polygon and oval, in this study it was important to fit into the rectangular shape of the façade and also to minimize wasted, shaded areas. Fig.6-5. Picture shows the fitting into the façade in three different forms. 96 The first step of the analysis investigated the status of all three forms in an area equal 32.7 square meters. We found that both the pyramid and the polygon will be commensurate with the overall shape of façade, but for the oval there was a loss about 7 square meters, which is equivalent to 24% of of the total area of the façade. The second study was the side surface area of the shapes. This question is fundamental, because of shallow angles of the sun early in the morning hours and after midday. Shallow angles of the sun are important issues in this research especially that the pyramidal shape is exposed to the sun shallow angles, and this helps to increase the total energy produced by photovoltaic panels in the early or late hours of the day time. Fig.6-6. Picture shows the fitting into the façade in three different forms by the side surface area (cross sectional) In this study, the pyramid shape will yield the largest cross-sectional area. The oval shape will yield a cross-sectional area close to the pyramid shape, but slightly less. The cross-sectional area of the polygon shape will yield less than 33% of the area of the pyramid. The figure also shows that there is some mutual shading from one pyramid to the other, which Revit Solar Radiation, considers. 97 Fig.6-7. shows how the pyramid shape will gain the solar radiation even from shallow angles 6-4. Avoid blocking the view The beauty of the building seen from the exterior is one of the issues which have direct relevance to the users of the building. The next most important issue is the view from the interior to outside of the building, and how these panels may give a special character to the building in several ways: such as reducing the sunlight entering into the space and controlling it as much as possible, reducing head load and glare inside the space. In addition, these panels will greatly help in breaking up sunlight in the space. It should not be forgotten that these panels will give a special character to the interior of the building, as well as this will help staff in creating a suitable and comfortable working environment. 98 Fig.6-8. The perspective from the inside to outside of the building 21 June Fig.6-9. Looking from the interior to exterior of the building 21 September Fig.6-10. Looking from the interior to exterior of the building 21 December 99 Fig.6-11. The final form of the shading system and shows the relative amounts pf photovoltaic and glass. Various studies have been done to investigate the overall shape of the screen for the building. This façade screen will give a special environment in each season: in summer the sun altitude will be much different from in the autumn and spring. In the summer sunlight will not be obstructed by the screening system and will not be able to enter the space. In winter the sun will be lower; in this case the sun's rays are nearer perpendicular to the human eyes; this has been studied in order to ovoid sunlight entering the space which will cause glare. Seasonal effects are shown in the following figures. 100 Fig.6-12. Defending the exterior of the building from the sun 21 June Fig.6-13. Protecting the southern façade of the building from the solar heat gain 21 September Fig.6-14. Protecting the building from the solar heat gain on 21 December 101 6-5. To create a shape that is easy to implement; not to require a custom shape from the photovoltaic manufacturers Many geometric shapes do not accept efficient installation of solar panels. From this point of view it was necessary to make the shape easy to use in a number of ways, including:  The shape should not require a special manufacturer.  The panels should be able to be installed on the construction system of the façade.  Site installation and maintenance should be facilitated.  The system should be clear and not complicated.  The system must be structurally stable. The study considered a number of factors: the sizes of units, the ability to be installed per floor, and how these units will work in one integrated system. These considerations helped us to arrive at the final form of the shading system of the building. 6-5-1. The form of the structural support system is able to support the installation of photovoltaic panels The proposed structural system is very simple and does not require a great effort to install. The system uses light steel trusses as the primary structure of the façade system. These trusses gave the façade a sense of lightness, softness in architectural perspective, and also structural strength and rigidity in addition to the luster and brilliance that gives the building a unique architectural style. 102 These trusses will be installed on 45 degree angle to give the solar panels the required angle to receive the radiation. In addition a shaded architectural space is created which will help to reduce heat reaching the building. The electrical wiring is connected through the pipes of the trusses in order to neaten the appearance of the overall façade system. Fig.6-15. Truss and Panel Assembly. Panels are attached to the top of the structure system by steel frames which are installed in the bottom of the panels. This avoids shading of the panels by the construction system. These panels were designed to harvest the greatest possible energy. 6-5-2. The exterior environmental space shaped by the system Green buildings are buildings designed, implemented and managed in a manner which keeps the environment in mind, reducing the impact of building on the environment by reducing the resource costs of its establishment and operation. Previous modern buildings often ignored the climate and its requirements. Glass surfaces 103 dominated modern architecture opened buildings to the outside rather than inside, leaving the facades of buildings exposed to direct sunlight Excessive direct sunlight and the associated heat gain constitute a burden on the electrical system for cooling loads. By contrast the shaded space between the building and the new shading system will help to create an intimate space filled with trees, palms and smaller plants to provide a thermal buffer and to further reduce the sun rays penetrating the building. In addition this space will make a place for the staff to take a break from work stress. Buildings need to be adapted to their climates. At the moment when a building is able to mitigate climate problems and, at the same time, use all the natural and technical resources available in order to achieve human comfort; at that moment the building can be called climate balanced. Fig.6-16. The space between the building and shading system has helped to fill the space with trees and palms which created an intimate space. 104 Chapter 7: Conclusion Creating an environment that is free from elements of pollution and contains an architectural language with a unique vocabulary has always been the main goal professionally and academically for the researcher. Experiencing a life that is not dependent on artificial systems, the fact that our ancestors were able to survive without electricity, using only what the earth provided them, has instilled a deep respect for the world we inhabit. This has inspiring the researcher to study ways in which we can create innovative building systems that are completely reliant on renewable sources of energy such as solar, wind, and gravity. Unfortunately, most buildings in Saudi Arabia are currently concerned with form and visual aesthetics and pay little attention to energy usage, operation and life cycle costs, and their impact on their environment and on neighboring buildings. Experiencing firsthand the negative impacts of these buildings on the environment prompted the researcher to pursue a study on sustainable design. Excelling at several sustainable design and environmental control courses initiated the research in various energy modeling and sustainable design software. However, exploring ways to the reduce energy consumption in the building while simultaneously employing clean, renewable sources of energy became the main area of focus for directed research in the Master of Building Science. A series of studies were conducted using various energy modeling programs such as Ecotect, Solar Radiation for Revit, and PGIS in order to determine the optimal angle for harvesting solar radiation at latitude of 105 24 degrees. Additionally, the use of a pyramid shape was also investigated in order to obtain the maximum amount of surface area without shading neighboring panels. Studies showed the optimal pyramid tested proved to be a .25m high x 1.41m (.17 ratios) wide form. The benefit of the pyramid came primarily from those pyramids on the edges where there was minimal mutual shading. The most enthralling part of the research was being able to build a piece of the façade system at the Saudi Solar Village in Riyadh. Testing the project under real life conditions showed results very similar to those obtained in the software simulations. Being able to touch the actual materials and experience the course in which a building is created from a series blueprints into a structure became a phenomenal story. The project involves the study of a dynamic photovoltaic building skin that works to reduce energy costs in two areas: First, by studying the optimal movement and angle placement of photovoltaic panels as a shading system in order to protect the building from solar heat gain. Secondly, the façade system was studied for its ability to harvest solar energy and turn it into electric energy in order to power building functions. Difficulties in building the pyramid shape in a short time was the major obstacle in the process of analysis and measurements, but thinking in the division of panels into sides equals in the area helped in finding all the great technical solution to this problem. 106 Fig.7-1. Divide the pyramid into pieces as it is shown to give the ease of building a relatively asymptotically to the pyramid. The government of the Kingdom of Saudi Arabia aims provides buildings for research as well as to simultaneously create a built environment that is sensitive to local climatic conditions and concurrent with advanced building practices. It is helpful to seek access to observations and opinions when creating an architecture and urban environment suited to the desert climate in order to help to reduce the construction and maintenance costs. This is the main topic of the study, to reduce energy loads and reduce the annual cost of electric power. On this basis, have been working closely to find help and technical system is to reduce the power consumed by the building and find a natural source of energy that feeds the building of indispensable energy. 107 Fig.7-2. The main objectives of the research. The objectives of this research have been achieved after the examination of several technical aspects, after it was contrary to all expectations the basis for this research. The test panels were able to harvest up to 943110 KWh/year. This is one of the most important discoveries in the research. The building currently consumes 758500 KWh/year of energy. Thusly, the photovoltaic façade will provide an additional 184610 KWh/year of energy that could be used to power neighboring buildings. 7-1. Summary Due to the fact that most office buildings in Saudi Arabia are currently designed to be completely dependent on mechanical systems, there is a large amount of pollution being produced every day. The large amount of radiation that is present in the region 108 prompted the research to explore ways in which photovoltaic panels could be applied to office buildings. A double skin façade was studied for two main aspects: to reduce the total cooling load by providing protection from overheating, and for its ability to harvest the maximum amount of solar energy. A series of simulations were performed using various software programs in order to optimize the shape and orientation of the panels. Finally, a series of test pieces were built and tested on site. The site calculations were similar to the results obtained in the software simulations. Additionally, the photovoltaic façade was able to harvest a greater amount of energy than is required to power the building, in this case. The extra energy can be stored and used to power other structures. Future research can include an on-site test which measures the total amount of radiation that is obtained yearly. These results should then be compared to those obtained from Solar Radiation software. 109 Chapter 8: Suggested future work In the field of research, we discover many of the problems that are related to research in advanced stages. These problems may be connected or not connected to research at all, and this is the nature of any kind of research. Generally, each one of the points that were found may one day become the subject of a great research topic. These points concerning the number of main themes are as follows:  Fabrication these panels as designed: This may be a topic for future research. The issue of using pre-fabricated panels versus custom made has been considered as mentioned in Chapter 4. Due to the fact that the building skin called for custom fabricated panels, the test pieces required a great amount of labor time, and financial resources in order to achieve the desired form.  On site calculations of the energy produced by the panels for an entire year: The limited amount of research time was of the main reasons that prevented the completion of the research. In the future a new research investigation might consist of the measurements of the yearly amount of solar energy harvested by the panels and compare these results to the numbers obtained from the software simulations.  Calculate the changes in the speed of air before the implementation of the panel facade and after: One of the intentions of using a double skin façade was to generate natural ventilation by providing an increase in the flow of air. The small openings created by the panels will 110 help to augment the amount of wind pressure thusly increasing the amount of wind speed.  Applying the panels in the west faç ade of the building: In the research the test models were only built on the southern façade of the building. However, when the panels were rotated towards the west they produced a greater amount of energy than when oriented south. Future studies should calculate the amount of energy produced on the western façade and compare these results to those of the southern façade.  Examine the benefits and financial variables: A financial study of the subject would be very beneficial when considering economic incentives. Will the energy generated by the panels help to pay back the initial cost of constructing the building façade? If this is possible, what is the time period it would take for the façade to pay for itself? 111 Bibliography Brannon Heather, 2007. "Effects of Sun on the Skin, Cellular Skin Changes Caused by UV Radiation", <http://dermatology.about.com/cs/beauty/a/suneffect.htm> Bowden Stuart and Honsberg C.B. "Photovoltaics CDROM", National Science Foundation, 2011, <http://pvcdrom.pveducation.org/SUNLIGHT/MODTILT.HTM > Crosby Kip, 2001. Future Tech, Solar Power Gets New Respect, Forbes.com <http://www.forbes.com/2001/05/31/0531solar.html> Design Guidelines (for the full year), 2011. Climate Consultant 5, Software. Feeney John, 1974. “The Magic of The Mashrabiyas, ' … in its beauty is the reason why the magic. . . has outlived the reality'.", Saudi Aramco World Volume 25, Number 4 July/August 1974. Institute of Energy Research, King Abdulaziz City for Science and Technology, 2009, <http://www.kacst.edu.sa/en/about/institutes/Pages/default.aspx > JUDITH MILLER. "IN SAUDI ARABIA, THE SUN SHINES BRIGHT ON SOLAR POWER". Published: November 1983, The New York Times. Kriscenski Ali , SIEEB Solar Energy-Efficient Building in Beijing, 2007, <http://inhabitat.com/sino-italian-ecological-and-energy-efficient-building-sieeb/> Landay Charler R. Optimum Orientation of Solar Panels. Macs Lab Incorporated Analytical and Environmental Services, 2010.http://www.macslab.com/optsolar.html Mashrabiya, from Wikipedia, the free encyclopedia, 2011, <http://en.wikipedia.org/wiki/Mashrabiya> Tyrväinen Liisa, Stephan Pauleit, Klaus Seeland, Sjerp de Vrie, Urban Forests and Trees. “Chapter 4, Benefits and Uses of Urban Forests and Trees. Springer 2005. Perez Richard. "To Track or Not to Track."Home Power 101, June/July 2004, (#101) pp. 60-63 < http://zomeworks.com/files/pv-trackers/copy_of_Homepower_june2004.pdf> 112 Saudi Arabia, from Wikipedia, the free encyclopedia, 2011, <http://en.wikipedia.org/wiki/Saudi_Arabia> Saudi Arabia Travel Guide, 2007. I Explore, <http://www.iexplore.com/world_travel/Saudi+Arabia/Destinations > Saudi Geological Survey, 2011, <http://www.sgs.org.sa/english/Pages/default.aspx> Solar Energy, from Wikipedia, 2011. The free encyclopedia, <http://en.wikipedia.org/wiki/Solar_energy> Smith Adrian Devaun, Skidmore, Owings, & Merrill. The Architecture of Adrian Smith, SOM: Towards a Sustainable Future. Images Publishing 2007. (Burj Dubai). Solar Radiation Basics, US Department of Energy, 10/20/2010, <http://www.energysavers.gov/renewable_energy/solar/index.cfm/mytopic=50012 'Uyayna, from Wikipedia, the free encyclopedia, 2011, <http://en.wikipedia.org/wiki/'Uyayna> World Climate Zones, 2011 <http://www.blueplanetbiomes.org/climate.htm > 113 Appendix Appendix A. Comparison of the solar radiation between the flat shape and the pyramid with 25cm depth Fig.A-1. Total Amount of Radiation Obtained at 0⁰ Left; flat panel, Right; pyramid. Fig.A-2. Total Amount of Radiation Obtained at 24⁰ Left; flat panel, Right; pyramid. Fig.A-3. Total Amount of Radiation Obtained at 47⁰ Left; flat panel, Right; pyramid. 114 Fig.A-4. Total Amount of Radiation Obtained at 90⁰ Left; flat panel, Right; pyramid. 115 Appendix B. Comparison of the solar radiation between the flat shape and the pyramid with 35cm depth Fig.A-5. Total Amount of Radiation Obtained at 0⁰ Left; flat panel, Right; pyramid. Fig.A-6. Total Amount of Radiation Obtained at 24⁰ Left; flat panel, Right; pyramid. Fig.A-7. Total Amount of Radiation Obtained at 47⁰ Left; flat panel, Right; pyramid. 116 Fig.A-8. Total Amount of Radiation Obtained at 90⁰ Left; flat panel, Right; pyramid. 117 Appendix C. Comparison of the solar radiation between the flat shape and the pyramid with 45cm depth Fig.A-9. Total Amount of Radiation Obtained at 0⁰ Left; flat panel, Right; pyramid. Fig.A-10. Total Amount of Radiation Obtained at 24⁰ Left; flat panel, Right; pyramid. Fig.A-11. Total Amount of Radiation Obtained at 90⁰ Left; flat panel, Right; pyramid. 118 Flat 0 Degree All Faces Face 1 Face 2 Face 3 Face 4 Face 1 Face 2 Face 3 Face 4 Face 1 Face 2 Face 3 Face 4 Tilt 0 352 352 8 8 346 346 14 14 340 340 20 20 Azimuth 0 8 -8 8 -8 14 -14 14 -14 20 -20 20 -20 90 Degree Tilt 90 82 82 98 98 76 76 104 104 70 70 110 110 Azimuth 0 8 -8 8 -8 14 -14 14 -14 20 -20 20 -20 24 Degree Tilt 24 16 16 32 32 10 10 38 38 4 4 44 44 Azimuth 0 8 -8 8 -8 14 -14 14 -14 20 -20 20 -20 47 Degree Tilt 47 39 39 55 55 33 33 61 61 27 27 67 67 Azimuth 0 8 -8 8 -8 14 -14 14 -14 20 -20 20 -20 35cm 45cm 25cm Fig.A-12. Total Amount of Radiation Obtained at 90⁰ Left; flat panel, Right; pyramid. Table.A-1. Table shows the angles of inclination and azimuth of each pyramid. 119 Fig.A-13. Chart shows the angles of inclination and azimuth of each pyramid. Fig.A-14. All angles that was potential in the study. 120 Fig.A-15. The annual energy consumption of the building as designed. 121 Fig.A-16. The annual energy consumption of the building by adding the shading elements in the south façade

Abstract (if available)

Abstract Problems with air conditioning and temperature control in the central region of Saudi Arabia are one of the biggest challenges facing architects today. This is what has driven scholars to find a number of ways to resolve this crisis. As a result, researchers have considered the use of adaptive façade shading systems as a possible solution to control and reduce solar heat gain in office buildings. It is well known that in the central region of Saudi Arabia the temperatures can reach up to 125 degrees Fahrenheit (51⁰C). This is the reason why researchers are trying to develop a new building skin system using solar panels in the surfaces of the façade as a source of solar energy for the building as well as to reduce the amount of solar heat gain inside the space. The use of these systems will help to drastically reduce energy costs because of their ability to convert thermal energy into electrical energy. The use of solar panels as skin for building facades is studied in two aspects. First, the use of panels is studied as a shading system in order to protect the building from solar heat gain. This involves studying the different angles of the sun throughout the day and creating a shading system, which may be dynamic and adaptive. Second, the use of solar panel façade systems is studied for their ability to harvest solar energy and turn it into electric energy in order to power building functions. This is a very important aspect since it allows the users of the structure to decrease external energy usage and save on costs. The idea of an adaptive building façade system incorporates the possibility of making the panels move automatically in response to the position of the sun. Such kinetic façade systems also give the building a new form at every moment and on every surface.

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Asset Metadata

Creator Al Olayan, Hamad Abdullah (author)

Core Title Harvesting energy with solar panels and adaptive shading for building skins: A case study of an office building in Saudi Arabia

School School of Architecture

Degree Master of Building Science

Degree Program Building Science

Publication Date 04/27/2011

Defense Date 03/30/2011

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag Adaptive Skin,harvesting energy,OAI-PMH Harvest,photovoltaic,projection surface,shading system,solar radiation

Place Name Saudi Arabia (countries)

Language English

Contributor Electronically uploaded by the author (provenance)

Advisor Schiler, Marc E. (committee chair), Pisca, Nicholas (committee member), Woll, Edwin (committee member)

Creator Email arch_1@live.com,halolaya@usc.edu

Permanent Link (DOI) https://doi.org/10.25549/usctheses-m3794

Unique identifier UC1463905

Identifier etd-Olayan-4583 (filename),usctheses-m40 (legacy collection record id),usctheses-c127-459807 (legacy record id),usctheses-m3794 (legacy record id)

Legacy Identifier etd-Olayan-4583.pdf

Dmrecord 459807

Document Type Thesis

Rights Al Olayan, Hamad Abdullah

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Repository Name Libraries, University of Southern California

Repository Location Los Angeles, California

Repository Email cisadmin@lib.usc.edu