Natural ventilation in vernacular architecture of Sistan, Iran; classification and CFD study of compound rooms

Extensive energy consumption in construction and ventilation has caused numerous environmental problems alongside huge waste of nonrenewable natural resources in today’s world. Meanwhile, vernacular architecture has been able to sustainably adapt to climate by developing creative and local solutions which provide a comfortable living environment, consume less energy and cause less pollution than the new ways of construction, one of which is wind induced ventilation. Vernacular architecture of Sistan (southeast of Iran) is not an exception to this rule. It utilizes its own set of unique elements and techniques that are compatible with region’s climate. This original article studies wind induced ventilation and its elements in Sistan’s architecture, including: (1) roofs (Sistani, Filpush and Barrel); (2) ventilator openings (Kolak, Surak and Dariche); and (3) walls. Then, this paper continues to classify three different compound room types in Sistan’s architecture, based on orientation and use of mentioned elements by documenting thirty-two sample houses across the region: (1) stretched against the prevailing winds; (2) stretched aligned with the winds; and (3) L shaped. CFD simulations are used to study the wind behavior and evaluate the ventilation performance of these room-types. These simulations lead to guidelines to enhance the ventilation performance of existing buildings and future constructions, including: where to put the windows, which orientation maximizes the natural ventilation performance, where to consider precautions to block the undesirable winds from entering and how far from each other should different room types be built.