Evaluating the shading and sunlit performance of the courtyards of traditional houses in hot-dry climate of Yazd city(Iran)

Courtyard, as a domestic pattern and a passive cooling system, affects thermal comfort of traditional courtyard houses in hot- dry and hot- humid regions. The aim of this research is to investigate the climate compatibility of courtyards of traditional houses based on shading and sunlit use in hot-dry climate of Yazd city; for this purpose, ten traditional courtyard houses were selected and modeled by Ecotect Analysis software. Afterwards, the average amount of shading and received sunlit by surrounding surfaces of the courtyards were calculated for all months of the year and the amount of shading-sunlit index was extracted for hot, cold and annual periods and therefore the degree of climate compatibility of the courtyards and the relationship between the geometric proportions of surrounding surfaces and shading-sunlit index were investigated. The results show that the annual average of the shading-sunlit index of the walls, floor and all surfaces of studied courtyards are 56%, 44% and 51%, respectively. Accordingly the walls, floor and the whole surfaces of the studied courtyards have an average amount of compatibility with the climate of Yazd city. The correlation between aspect ratios and the deviation angle of the courtyards and the shading-sunlit index, shows that by increasing the ratios of L/W and H/W and decreasing the deviation angle, the amount of walls shading-sunlit index decreases, an on the contrary, the amount of the courtyard floor index and the whole surfaces index increase. Furthermore, as the ratio of H/L increases and the deviation angle decreases, the amount of shading-sunlit index of the walls and the whole surfaces decrease and the courtyard floor index increases.