Windcatcher

(water reservoir) with windcatchers (openings near the top of the towers) in the central desert city of Yazd, Iran in Abarkooh, Iran, has an elaborate 18-m windtower with two levels of openings, plus some smaller windtowers. A windcatcher, wind tower, or wind scoop ( ) is a traditional architectural element 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. Neglected by modern architects in the latter half of the 20th century, the early 21st century saw them used again to increase ventilation and cut power demand for air-conditioning. Generally, the cost of construction for a windcatcher-ventilated building is less than that of a similar building with conventional heating, ventilation, and air conditioning (HVAC) systems. The maintenance costs are also lower. Unlike powered air-conditioning and fans, windcatchers are silent and continue to function when the electrical grid power fails (a particular concern in places where grid power is unreliable or expensive).…

(water reservoir) with windcatchers (openings near the top of the towers) in the central desert city of Yazd, Iran]] in Abarkooh, Iran, has an elaborate 18-m windtower with two levels of openings, plus some smaller windtowers.]] A windcatcher, wind tower, or wind scoop ( ) is a traditional architectural element 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. Neglected by modern architects in the latter half of the 20th century, the early 21st century saw them used again to increase ventilation and cut power demand for air-conditioning. Generally, the cost of construction for a windcatcher-ventilated building is less than that of a similar building with conventional heating, ventilation, and air conditioning (HVAC) systems. The maintenance costs are also lower. Unlike powered air-conditioning and fans, windcatchers are silent and continue to function when the electrical grid power fails (a particular concern in places where grid power is unreliable or expensive). Windcatchers rely on local weather and microclimate conditions, and not all techniques will work everywhere; local factors must be taken into account in design. Windcatchers of varying designs are widely used in North Africa, West Asia, and South Asia. A simple, widespread idea, there is evidence that windcatchers have been in use for many millennia, and no clear evidence that they were not used into prehistory. The "place of invention" of windcatchers is thus intensely disputed; Egypt, Iran, and the United Arab Emirates all claim it. Windcatchers vary dramatically in shape, including height, cross-sectional area, and internal sub-divisions and filters. Windcatching has gained some ground in Western architecture, and there are several commercial products using the name windcatcher. Some modern windcatchers use sensor-controlled moving parts or even solar-powered fans to make semi-passive ventilation and semi-passive cooling systems. Windscoops have long been used on ships, for example in the form of a dorade box. Windcatchers have also been used experimentally to cool outdoor areas in cities, with mixed results; traditional methods include narrow, walled spaces, parks and winding streets, which act as cold-air reservoirs, and takhtabush-like arrangements (see sections on night flushing and convection, below). Byggnadskonsten, Fornegyptiska boningshus, Nordisk familjebok.png|Dwelling house in Ancient Egypt with windcatcher. From a painting at the Pharaonic house of Neb-Ammun, Egypt, which dates from the 19th Dynasty, c. 1300 BC (British Museum). Ancient Egyptian House miniature showing windcatchers.jpg|Ancient Egyptian House miniature showing windcatchers, dating from Early Dynastic Period of Egypt, found in Abou Rawsh near Cairo. Now in Louvre. RPM Ägypten 003.jpg|Model of an Ancient Egyptian house with windcatcher, Roemer- und Pelizaeus-Museum Hildesheim صور متنوعة من داخل القلعة 26.jpg|Windcatchers and roofs shading narrow airshaft courtyards, Cairo Citadel View over Khartoum.jpg|Windcatchers in Khartoum, Sudan File:Dolat Abad Garden - Pavilion 02.jpg|The windcatcher of Dowlatabad Garden in Yazd, Iran: one of the tallest existing windcatchers File:Borujerdiha.jpg|Borujerdi House, in Kashan, central Iran. Built in 1857, it is an excellent example of ancient Persian desert architecture. The two tall windcatchers cool the andaruni (courtyard) of the house. File:Windcatcher at Ganjali Khan Complex, Kerman.jpg|Windcatcher of Ganjali Khan Complex, in Kerman, Iran File:Badgir-golestan-palace-tehr.jpg|Golestan Palace, in Tehran, Iran File:نمای زیرین بادگیر.JPG|A windtower from below, interior view, showing that it is partly closed off

Text derived from https://en.wikipedia.org/w/index.php?oldid=1359825960 under CC BY-SA 4.0; modifications have been made.