desert tales learning our lessons
vernacular | iran by shamim alaei
heat and dust wind and sand sun and shade old and new hot and cold
Strategising to improve quality of life in the contemporary cities of the developing world has been the focal point of many studies over the last few decades. Imported technologies, design concepts, standard models and urban solutions to modernise the developing world often ignores the strong identity of local communities whose architecture contrasts strongly with that of the western world. In Iran, the gap between idealistic intentions and actual achievements has been so sizable that it has resulted in severe social and environmental complications. These dilemmas have forced designers to re-focus on the principle element upon which vernacular architecture is based: weather. Iran has extreme geography and weather. A temperate, well-cultivated zone on the coast of the Caspian Sea in the north is separated from a central hot dry zone by the Alborz and Zagros mountain ranges that run from the Iran-Turkey border to the
Persian Gulf, embracing the Lut and Kavir deserts. On the edge of this topographical split, very old cities such as Yazd, Kerman and Kashan reveal spectacular traditional architecture with cogent lessons on building in extreme climates. Here is just one: ventilation. This region is one of the driest parts of the country; the ground is covered with sand, salt and sediments whose vulnerability to high wind erosion is compounded by a lack of vegetation. Such conditions gave birth to a most complex sustainable architecture. It emerged from an incremental process of house-building by dwellers who collaborated in erecting, expanding and improving their buildings over centuries. Dense urban fabric of uniform height allows buildings to shade one another, to reduce surface areas exposed to solar radiation and to create narrow, breezy, street networks. Public squares or meydans
in dense urban fabric promote cool winds: these internal open spaces heat up faster than the surrounding buildings and as hot air rises it draws air from the street network, setting up a breeze in all directions. A similar concept is used in individual buildings: summer and winter rooms face an inner courtyard of usable and protected outdoor space. Winds pass over the buildings creating areas of low pressure in the courtyards resulting in air pulled in through the exterior walls’ ventilation openings, through the rooms and into the courtyards. Another element of a natural ventilation system is the wind-catcher, or badgir . The design of these towers is directly associated with the direction, speed, gustiness and frequency of each region’s winds. Inlet openings at the top of the tower capture the breeze off the desert. The temperature of the captured air cools as it travels down the tower to outlets on the leeward side
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On Site review 21: stormy weather
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