It has been proved that the behaviors of both single and multi-pressure types of traditional wind catchers are related to the conditions of lower openings. But still the quantity and the quality of such relation is not recognized. So, this paper aims to indicate the impact of varieties in changing the conditions of such openings and the outdoor wind direction on the velocity of indoor flow in both types of traditional wind catchers. Therefore both types of traditional wind catchers simulated using models in CFD. In this research variations of different border conditions such as lower space without and with opening have been simulated. Also, in case of outdoor wind direction, different angles including 0, 45, 90, 135 and 180 tested. Results of this research showed that in different conditions, the multi-pressure traditional wind catchers show more stable indoor flow, more predictable behavior and finally more efficiency; compared to the single pressure traditional wind catchers.
