Green Prophet looks to ancient Iran for some current alternative ideas to electricity-powered air con. Catch the wind with the bagdir wind tower!
The concept of “green building” has taken off in Israel over the last few years. The need for ecologically efficient housing and offices is becoming more urgent as the cost of heating and cooling skyrockets and water becomes ever more scarce.
But environmentally-conscious buildings have been around much longer than the modern environmental crisis. Outdating gas-guzzling air con units by generations, bagdirs – or windcatchers – have been cooling down the people of Yadz, Iran, since the 19th Century. These towers spike the skyline of the Iranian desert city like antiquated skyscrapers.In the current edition of Green Building Magazine, Sue Roaf explains how the stone structures channel wind down into a shaft which in turn cools or heats the rooms below, allowing them to remain comfortable all year with zero carbon impact.
As well as using smart technology, the windcatchers of Yadz’s success depends on effort from the building’s inhabitants too. People can reduce their energy use by what Roaf calls “occupant behaviour strategies,” for instance, moving to warmer or cooler rooms.
This contrasts to the approach of modern Western design where “the individual chooses the climate for a room”:
“While nomads in Iran migrate from summer climates, for those who remain in Yadz replace the long migration by a short intra mural migration, within the walls of a single house.”
In the summer, when temperatures soar to over 40 degrees C, this means using the ground floor in morning and evening, whilst escaping to the roof at night – a popular pastime in cities like Tel Aviv. Other strategies include watering floors, wearing lighter or warmer clothes, or – my favourite – taking an afternoon nap in the heat of the day.
Heirloom wind catchers.
How wind catchers work.
But the bagdirs of Yadz do have their dark side. Though partly funded by the silk trade, most of the windcatchers owe their existence to local merchants who made their fortunes from the British opium trade to China during the Opium Wars.