Evaluating the Existence of a design mechanism based on natural ventilation in the traditional architecture of cities in hot-arid climate without the use of windcatchers (case study: outer space of four-sided Qajar buildings in Shiraz)

Airflow in buildings is limited by walls, floors, and building roofs and it is possible to slow down unpleasantly, this slowdown, in addition to the imposition of an energy load, can have a harmful health impact on residents when there is energy shortage. Natural ventilation helps architects to minimize the cost of energy needed to create comfort conditions in the right way. In buildings with a central courtyard layout, the shape and proportions of the yard affect the pattern of flow and wind speed, and the size of the openings affects the volume and speed of the wind entering the building. Therefore, the present study has been carried out with the assumption that a significant relationship between openings and yard proportions of local residential houses can be found. Hot-arid climate has been chosen since it’s highly dependent on ventilation and Shiraz has been chosen as an example of cities in such climates. In search of the existence of recurring ratios in existing houses, case studies have been selected in a historical period with similar characteristics and minimal intervening factors. The descriptive-analytic research methodology is chosen using documentation, photography, field surveys, and software analysis. Finally, these relationships have been extracted from four-sided samples with courtyards by calculations of volume airflow, the proportions of courtyards, openings, wind-facing façade, built area, etc. The obtained ratios have a specific pattern in these studied cases, and the proportions have limited numerical range based on the characteristics of the buildings.