There are many different types of wind-catchers, whose forms and functions are based on the climatic conditions of their regions. The most common ones are the unidirectional (malqaf, windcatcher), and the multi-directional (Badgir, windscoop).
Unidirectional windcatcher (Malqaf)
In the early Islamic-Arab houses the courtyard represented an intermediary space between the entrance and the guest area. Meeting casual male visitors always took place in the takhtabush , a room with a side open to the courtyard. On the other hand, important male visitors would enter indirectly from the courtyard to another large reception hall with a lofty central space, which was flanked by two spaces at a slightly higher level. In the Mamluk period in the twelfth century, a change in the style of the house took place that involved the covering of the courtyard, and the introduction of the qa’ah as the main reception hall in the house.
The qa’ah consisted of the dorqa‘ah (a central part of the qa’ah with a high ceiling covered by the shokhshekhah (wooden lantern on the top)) and two iwans (sitting areas) at a higher level on both the north and south sides. The lantern is provided with openings to allow the hot air to escape. Its shape could be square, octagonal, or hexagonal. It was also flat on the top, in order to help the upper layer of air to be heated up through exposure to the sun. With the covered courtyard, a new system of ventilation was invented to achieve thermal comfort inside the qa‘ah. This was the malqaf (a wind catch), which is a shaft rising high above the building with an opening facing the prevailing wind and constructed on the north qa’ah. It traps the cool air and channels it down into the interior of the building. The size of a malqaf is determined by the external air temperature. If the air temperature is high, a smaller size is required and if it is low, a larger size is preferred.
Image credit: The Malqaf of the Main Qa-a of the Suheimi House
Image credit: Salsabil, La Zisa Palast, Sicily, Italy
To increase the humidity of the air coming from the malqaf, the salsabil was also introduced. It is a marble plate, decorated with wavy patterns and provided with a source of water. The salsabil was put against the wall of the opposite side of the iwan and placed at an angle to allow the water to trickle over the surface. However, this new system of ventilation combined the malqaf, the salsabil and the lantern in one design to assure a good circulation of cool air in the qa‘ah. A good example is the fourteenth century Muhib Ad-Din Ash-Shaf’i Al-Muwaqqi house in Cairo which best illustrated this combination.
Air movement:The qa‘ah of Muhib Ad-Din, Cairo (c. 1350)
Badgir (Multi-Directional Windcatcher)
In Persia (Iran) and the Gulf area, the windcatcher is called badgir. It is a multi-directional windcatcher, which have four openings at the top to catch the breezes from any direction. Air circulation coming from the badgir can be adjusted by opening or closing one or more of the scoops. Placing a clay porous pot, help humidify and cool the air coming from the badgir. The plan of the badgir may take different shapes, but the square plan is the most common used one. The badgir is divided by two partitions placed diagonally across each other down the length of the badgir’s shaft.
The badgir can also be used in pairs or four at a time to cool underground water tanks. In addition to its role as a ventilation device, the badgir is usually used as a decorative element in buildings as shown in.
Hassan Fathy, Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates. Chicago, 1986.
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