Thermal Performance of dorchah, kolak, and kharkhona during the Warm Period of the Year in the Vernacular Houses of the Sistan Region

Thermal comfort is one of the most important issues in architecture. Although studies in this field began in the early twentieth century yielding significant achievements, one of today’s architectural challenges is to provide thermal comfort with the least dependence on fossil fuels for the inhabitants of buildings. At the same time, it seems that vernacular architecture, which is tested through centuries of experience, has had significant success in creating climate-responsive strategies that can still be utilized to design passive and sustainable architecture in different climates. Vernacular architecture of the region of Sistan is an example that has been able to make indoor climatic conditions often acceptable for residents. Therefore, through a case study, this paper investigates the performance of these strategies and their roles in providing thermal comfort in indoor spaces in Sistan during the warm period of the year. For this purpose, a vernacular building was selected, and through qualitative and quantitative analysis, the performance of dorchah, kolak, and kharkhona strategies that help provide thermal comfort in the warm period of the year was investigated. Their impact on indoor air temperature, relative humidity, wind speed, and thermal comfort have been analyzed. The results show that although in the warm period of the year, the indoor environmental parameters of spaces are not in the range of classic thermal comfort temperatures (23-27 °C), the use of climatic strategies has a significant effect on improving these parameters at different times of the day. In addition, indoor environmental parameters with the application of kharkhona were in a good range during hot times of the day, while dorchah and kolak can make indoors tolerable when the outdoor environment is cooler.