Roghaiyeh Mehmani - Department Of Architecture, Bostan Abad Branch, Islamic Azad University, Bostan Abad, Iran

Natural ventilation is one of the most effective factors is the creation of thermal comfort. This factor leads to comfort conditions in hot and humid climates through the implementation of wind current, a decrease in the relative humidity and an increase in surface evaporation. In order to modifying climate condition concerning buildings, some construction builders have made an effort to build a structure under the ground with a depth of 5 to 12 meters in Dezful which is considered to be one of the hot and semihumid cities. This sustainable cool underground structure also called Shawadoun -consists of a room or some rooms with an annual average temperature of 2in whi h n in r s in th depth and the volume of Shawadoun causes cooler and more sustainable air –is one of the suitable approaches which is in accordance with the environment and creation of thermal comfort conditions through the stability of th rth’s annual temperature and natural ventilation. This structure was used in the summer for daily resting and also storing food stuff and in general to fit cooling requirements. Among the Shawadoun of the adjacent houses whose residents are often a family member or relatives, they used to dig some channels to connect Shawadoun to each other so that air ventilation inside Shawadoun would be performed properly. The cool air was directed into the rooms through the holes which extended from Shawadoun to the rooms of the house. Shawadouns consisted of vertical channels to provide day light and also the light catching channel was located under the surface of the yard. Some Shawadouns fulfilled the ventilation process by using wind catchers which sometimes functioned as air conditioner. In the summer, the unglazed clay pots were placed on the mouth of these channels, and since the air current was always flowing inside the channels and the surface of the clay pot was wet due to water inside, the evaporation of the water over the pot caused the coolness of the water inside the pot. It must be mentioned that the level of underground waters in this region is very low, and since digging the ground, especially in Dezful, is fairly easy, these two problems have helpedestablish and expand Shawadoun

Shawadoun, natural ventilation, thermal comfort, sustainable architecture