Climatic effects on school buildings : methods of optimising the energy performance of school buildings in the different climatic regions of Iran
Since the 1970s, over a thirty-year period, awareness of the limitation in fossil fuel reserves has been increased steadily and international attention has been given to an energy conservative way of life. Like many developing countries, today Iran is beset with serious energy supply difficulties. The main issues are the rapid increase in energy demand/cost, air pollution caused by over use of fossil fuels (usually used in buildings for heating purposes), the limitation of fossil fuel resources and the difficulties in the transportation and distribution of fossil fuel especially in winter around the country. Therefore, it is crucial to adopt a new strategy for sustainable energy use and to consider the application of renewable energy technologies in the design of buildings. Solar energy is one of the most significant and technically exploitable renewable energy resources available in Iran. This needs to be taken into account seriously, regarding both economical and environmental problems in that country. Since school buildings in Iran are one of the major consumes of energy for heating, cooling and lighting purposes and according to their inappropriate current design from the energy efficiency point of view, this study has been performed with the aim of developing methods of optimising the energy performance of school buildings in Iran and promoting low energy architecture in the design of these buildings in different climatic regions of Iran. For this purpose, first the Iranian climatic has been reviewed and appropriate classification was presented. Since solar radiation data have not been calculated in Iran so far, there was a need for a precise calculation of solar radiation for each and every city in order to better exploit the benefits of solar energy for the future of this country. Therefore, the method of calculation of solar radiation in different cities of Iran based on European Solar Atlas and Islamic Republic of Iran Meteorological Organisation's statistics was presented and a spreadsheet excel program was developed for the calculation of solar radiation data of 152 cities of Iran. A comparison has been made between the excel program and Meteonorm. The result showed that the excel program data were more useful in that they were more precise and much more reliable compared to Meteonorm data for Iran. Also, based on solar radiation data another excel program (based on the admittance method) was developed for the calculation of heating, cooling and lighting energy use of buildings in Iran. By using this program the effect of window design on the thermal performance of school buildings and the response of walls and roofs to solar radiation was investigated in hot climates. Substantial saving in the annual running cost of school buildings as much as 14% was achieved under appropriate window arrangement. In order to explore the problems of existing design, a case study has been performed on current schools design in Iran and the energy use of these schools was analysed.