Investigation of the effects of sunlight on the surface of the domes of mosques in desert areas

The construction of religious buildings in the past would occur by taking into account the comfort and convenience of the building, in the face of harsh climatic conditions of the region. Mosques, as one of the religious buildings of our country, have been built everywhere in various climatic conditions, especially in desert areas with dome roofs of different shapes and sizes. This study seeks to investigate the performance of domes in desert areas in terms of form and dimensions versus the amount of sunlight absorption. For this purpose, some weather file data were obtained from the meteorological stations of Isfahan and Yazd cities. Also, the maps of the domes of the mosques were received through library documents in the field of architecture. In this regard, five examples of domes in desert areas were selected, including the domes of Imam of Isfahan, Mir Chakhmaq, Sheikh Lotfollah, Saro Taghi and Ali Mosque. Then, the domes were modeled with accurate dimensions by the 2017 Revit software. This was done to calculate the absorption of sunlight on the surfaces of the domes on the hottest days of the year at three times including 2, 4, and 6 p.m. in desert areas by the use of the energy Plus Ladybug and Honeybee plugins RADIANCE. The results showed the amount of sunlight absorption on the surfaces of the domes depends on the shape and the dimensions of the domes. At 2 o'clock p.m., domes with a high rise and domes with a low rise were exposed to the sun for 58% and 75% respectively. At 4 o'clock p.m., domes with a low rise and those with a high rise were exposed to the sun by 68% and 51%. Also, at 6 o'clock p.m., the domes with a high rise and those with a low rise had the exposures of 49% 46%. The performance of high domes is, therefore, much more optimal than that of low domes at the hottest times of the day. This is because high domes provide more shade during these hours.