Wind flow patterns in ancient wind catchers of Yazd based on a long term measurement (case study: Mortaz house)

Windcatchers in Yazd are a prominent example of energy saving through building design in hot-arid climates. Therefore, careful quantitative and numeric study of their performance and behavior can be beneficial towards achieving climate-friendly solutions. this research is carried out based on field studies and long-term measurement of climatic factors in a traditional windcatcher in Yazd. In this study the results of long-term measurements of wind flows around and inside the windcatcher of Mortaz house as a sample in Yazd’s historical fabric are presented to examine its performance in utilizing wind energy.  A local station for extracting micro-climatic data from the study region was installed and the windcatcher was equipped with devices and censors for climate data measurement. comparing the velocity profiles for the outward airflow of the windcatcher and the local wind flow in hottest and coldest days of the year indicated a higher conformity between the abovementioned airflows in the cooling period (hot days of the year). Furthermore, the higher velocity of winds in summer compared to winter in the region which causes increased airflow inside the windcatcher during the cooling season also indicates better performance during the cooling season compared to the heating season (cold days of the year). This also applies to ventilation during the night. Physical properties of the windcatcher were also compared with local climatic conditions. The orientation of the windcatcher allows it to receive 80% of dominant wind flows during summer, among which 48% are desired wind flows. therefore the goal of this paper is to present the pattern of wind behavior in the studied windcatcher in order to examine its conformity with local climatic conditions.