International Journal of

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Nowadays, with the development of the economy, the demand for energy is increasing rapidly while the energy supply is growing shorter and shorter. Researches indicate that energy consumption in the residential sector counts for the main parts of the total energy consumption. This paper evaluates the effect of building orientation on exposure to the solar radiation in a NESW orientated case of urban residence in semi-arid climate. SW envelope, with an annual exposure of 13.52 percent, only improves the thermal comfort of the house because of its annual climatic radiation trend. For vertical NE surface with insufficient winter radiation exposure of (0 %) and cool summer radiation exposure of (3.38 %), it could be concluded that the NE elevation is suitable and in demand in the summer but not in the winter. Total annual horizontal solar radiation exposure percentage of (83.04%) indicates that huge non- climatic roof radiation is inappropriate and should be omitted. Finally, the effects of solar radiation envelopes on electricity and natural gas consumption were thoroughly discussed.

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The physical-geometric characteristics of buildings have a very important role in the regulation of microclimate conditions and the thermal situation of interior and exterior spaces of buildings. This research aims to investigate the amount of received direct radiation energy of vertical surfaces in buildings and determine the appropriate form, aspect ratio, and orientation of buildings in the cities of Ardabil, Tabriz, Sanandaj, and Hamedan in the Northwest of Iran with cold climate. For this purpose, six polygonal forms (with the same floor area and height) including square, rectangle, hexagon, octagon, hexadecagon (16-sided), and triacontadigon (32-sided) were selected to be examined. Afterward, the specified optimal form(rectangle) was surveyed with the aspect ratios of 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2 and in the orientations of 180º, 165º, 150º, 135º, 120º, 105º SE and SW. Using the “Law of Cosines” computational method, the amount of received direct energy on vertical surfaces has been calculated and processed, for different months and during the cold and hot periods of the year. The results of the research show that the appropriate form of the buildings in the studied cities is a rectangle with an east-west orientation. The most suitable aspect ratio for the rectangular form with east-west orientation in the cities of Ardabil, Tabriz, Sanandaj, and Hamedan is 1:1.2. The appropriate orientation for the determined aspect ratio in the studied cities is 165° Southeast.