A Study of the Functions of Traditional House Entrance's Depth and Shadow on Outdoor Thermal Comfort in the Historical Context of Shiraz

The thermal comfort achievement was not only for the interior spaces. Outdoor thermal comfort was a main science in urban design in all aspects. One of the main parts of urban planning is entrances, due to having better social interactions. The entrance has different roles as providing gate and administering the entry and exit, infiltration, equivalence, readability and initiation. Due to the research on the traditional building’s entrance, the outdoor thermal comfort of residents has an affective role in entrance characteristics. In this research, the role of traditional house entrance depth and shadow on outdoor thermal comfort was investigated. The case studies were 10 traditional house entrances in the historical context of Shiraz. The entrances of these houses are like a horizontal shading device. The houses were constructed in Qajar period with random selection from 64 houses. The monthly maximum and minimum sun altitude angle was calculated and then for the hottest hour of a day (10-15) the shadow height was calculated. In this research the effect of sun azimuth angle was supposed zero. The monthly average of shadow height was calculated and with the comparison of the monthly and yearly amount of entrance shadow, the winter and summer shadow height and depth were performed. The ratio of shadow height of summer was 11.61. Therefore, the outdoor thermal comfort in winter (with solar heating) and summer (with shadow cooling) (hypothesis) was achieved. The maximum amount of shadow height was 20.8 m (for a house with 2.3 m entrance depth) and the minimum amount was 1.8 m (for a house with 0.2 m entrance depth). In addition, the optimized entrance depth with south direction for Shiraz was 0.2207. It was showed that the entrance depth of about 22 centimeters could achieve the summer shadow and winter solar radiation. So, in the selection of direction, form and position, it could be useful and could help to achieve the best entrance depth and shadow for outdoor thermal comfort. Finally, the formula of the best depth and height was determined and the shadow height, depth, direction and amount in summer and winter could be achieved.