Ancient windcatchers in Iran give architects cooling inspiration

Tall chimney catches breeze, channelling it into house, displacing warm air that is then expelled through windcatcher

BY David Hambling

Electricity consumption rises with the temperature as people turn on air conditioners in the summer. But many homes in Iran are still built with a simple but effective cooling device known as a windcatcher, which requires no electricity and dates back centuries.

A windcatcher looks like a tall, decorative chimney, usually with two or more open sides. It catches the breeze that blows well above ground level and channels it down into the house below.

This displaces warm air that is expelled through the opposite face of the windcatcher. In some designs the incoming air blows over water, providing further cooling. Studies show that this simple design can reduce the temperature inside a building by 8C to 12C.

Even in the complete absence of wind, a windcatcher acts as a solar chimney: warm air rises through it, drawing down cooler air into the building from the other side.

Nobody knows how far back windcatchers date. Ancient Egyptian art depicts what might be windcatchers from more than 3,000 years ago, but some scholars maintain that structures found on the remains of a Persian temple are the oldest genuine windcatchers.

Now architects are taking another look at windcatchers, redesigning them with computer-aided tools for maximum environmentally friendly cooling and ventilation.