A windcatcher, wind tower, or wind scoop is a traditional architectural element, originated in Iran (Persia), used to create cross ventilation and passive cooling in buildings. Windcatchers come in various designs, depending on whether local prevailing winds are unidirectional, bidirectional, or multidirectional, on how they change with altitude, on the daily temperature cycle, on humidity, and on how much dust needs to be removed. Despite the name, windcatchers can also function without wind.
An ab anbar (water reservoir) with windcatchers (openings near the top of the towers) in the central desert city of Yazd, Iran
Aghazadeh Mansion in Abarkooh, Iran, has an elaborate 18-m windtower with two levels of openings, plus some smaller windtowers.
Wind tower, exterior, Dubai Museum
The same interior. This wind tower has four openings and brown cloth vertical walls on the interior diagonals, so it can catch the wind from a range of directions.
Cross ventilation is a natural phenomenon where wind, fresh air or a breeze enters upon an opening, such as a window, and flows directly through the space and exits through an opening on the opposite side of the building. This produces a cool stream of air and as well as a current across the room from the exposed area to the sheltered area. Other terms used for the effect include, cross-breeze, cross-draft, wind effect ventilation and cross-flow ventilation.
Cross-breezes work when two windows are opposite of each other.
