Adaptive behaviors and summer thermal comfort in the indoor environments of the vernacular architecture of Sistan region, Iran

The adaptive behaviors of the residents of buildings operated by natural ventilation (NV) have a special role in providing thermal comfort with minimum amount of dependence on fossil fuels. The "adaptive" idea dates back to the 1960s and 1970s. In addition to analyzing thermal comfort, it helps to improve standards and forecasting models of thermal comfort, as well as developing more accurate algorithms for controlling the indoor environment and is based on in-situ measurement. As a result, research in different regions and lesser known climates is very important. According to this research, Sistan region has special climatic characteristics that are different from other regions in hot and dry climate and thermal comfort in this region can be interpreted based on adaptive method. Therefore, this study investigates these adaptive behaviors and their effect on thermal comfort in NV buildings in Sistan region. To this end, six buildings in six villages of Sistan Region were selected for a longitudinal study that was carried out in July 2019. In addition to measurement of the climatic parameters of the indoor spaces of these buildings, a questionnaire-based field study of thermal comfort was conducted. In this study, the type and timing of adaptive behaviors were recorded and analyzed according to thermal responses. This study indicated that the most important adaptive behaviors used during the hot days of Sistan Region are Watering Khaarkhane, Opening Dorche, Opening Kolak and Watering one’s head and face which are different from the common adaptive behaviors have been investigated in previous studies both in terms of form and thermal performance. With the help of these behaviors, the residents of Sistan Region have been able to achieve thermal comfort in 51% of the times of the very hot days of the region without using any mechanical cooling device. This study also showed that Watering Khaarkhane has a better thermal performance compared to Opening Dorche and Opening Kolak. Determination of neutral temperature (31 °C) based on regression analysis and thermal comfort zone for 80% of occupants (27.3-34.6 °C) were the other results of this research. Although these values are far from the neutral temperature and the ASHRAE summer thermal comfort zone (23-27 ° C), this distance can be explained by the compatibility method.