Performance evaluation of a single-side windcatcher in the transitional seasons (case study: Khousf town, Southern Khorasan Province, Iran)

Purpose Life experience in hot and arid areas of Iran has proved that in the transitional seasons (spring and autumn) in which the climate is not too hot, passive cooling systems such as windcatchers (baadgir) have functioned well. This paper intends to investigate the efficiency of a single-side windcatcher as a passive cooling strategy; the case study is the Bina House windcatcher, located in Khousf town, near Birjand city, Iran. Design/methodology/approach To achieve the aim, air temperature, relative humidity, wind data and mean radiant temperature were measured by the related tools over five days from September 23 to October 23. Then, the thermal performance of the windcatcher was examined by analyzing the effects of all these factors on human thermal comfort. Quantitative assessment of the indoor environment was estimated using DesignBuilder and its computational fluid dynamics (CFD) tool, a thermal comfort simulation method to compare the cooling potential of the windcatcher. Windcatcher performance was then compared with two other common cooling systems in the area: single-side window, and evaporative cooler. Findings The results showed that both windcatcher and evaporative cooler can provide thermal comfort for Khousf residents in the transitional seasons; but the difference is that an evaporative cooler needs to consume water and electricity power, while a windcatcher is a passive cooling system that uses clean energy of wind. Originality/value The present study, by quantitative study of single-side windcatchers in a desert region, measured the climatic factors of a historical house and compared it with thermal comfort criteria. Therefore, the results of field measurements were analyzed, and the efficiency of the windcatcher was compared with two other cooling systems, namely single-side ventilation and evaporative cooler, in the two seasons of summer and autumn (transition seasons).