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Yakhchals (Persian Yakh = ice Chal = pit)

If I told you that in 400BC Persians were able to keep ice from melting when temperatures often reach 40 degrees and without the luxury of electricity, you’d probably think I was making it up. In fact, it is true and I find the invention and use of a Yakhchal  fascinating. By keeping ice as ice for a prolonged period it meant that houses could be kept cool by using the blocks in the summer, and food could be “passively refrigerated” to substantially extend its shelf life in the heat.

 

Yakhchal and badgirs together

Yakhchal and badgirs together

Yakhchals are domed structures constructed from mud bricks with underground space excavated below ground level. The dome and underground chamber are also insulated with a very effective and delightful mixture of sand, clay, egg whites, lime, goat hair and ash up to 2 metres thick. We found a yakhchal and badgirs together on the outskirts of Na’in between the new town and the ancient citadel and I can vouch that the ice house is a very large building. Sadly, the ice house was locked and we were unable to find anyone who could let us in to take a look.

Ice could either be brought down from the mountains in early winter and stored until the following summer or, more commonly, the water from the Qanats was channelled into areas which were sheltered from the sun and wind so that it froze overnight in the notoriously cold winter desert temperatures. Blocks could then be cut and stored in the Yakhchal ready to use the following summer.

Whilst most of the ice houses in Iran are now abandoned in favour of electric white goods, some communities in desert areas across the globe are looking at the ice house method of keeping things cool as an alternative to using electricity-“off grid living”. Instead of ice blocks however, 2 litre bottles of water are filled and used. Not only are these easier to transport it also avoids unnecessary plastic going to landfill.

In this day and age of reduce, reuse, recycle, ice houses could still yet make a come back!

Further reading:

The ice houses of Iran by Hemming Jorgensen

Ancient ice houses of Iran (some great photos)

Badgirs (Persian Bad = wind, gir = catcher)

Badgirs, or windcatchers, do exactly what it says on the tin; they catch wind. Built from brick or mud and adapted to take into account the direction of airflow depending on its intended use, these structures are the forerunners of air-conditioning systems but again, without the need for electricity.

Badgirs were, and still are in some parts of Iran, used to cool buildings and act as ventilation. The Yadz area in particular is renowned for the high numbers of wind catchers in use and this is no surprise given its location on the edge of the desert. Badgirs are usually high towers and have either one, four or eight openings. For air-cooling a house, the tower would often have one opening facing the prevailing wind so that it drags the air down and into the house thus keeping the air continually moving whilst cooling.

When used alongside a Qanat, windcatchers can also be adapted so that they draw air up from the water tunnel which cools as it passes over the water and up through the cool ground. For this to happen, the opening will be facing away from the prevailing wind.

Strangely, windcatchers are also effective cooling mechanisms when there is no wind! In this situation, hot air travels up and out of the tower as a result of the pressure gradient created. This leaves the lower levels of buildings extremely cool and welcoming on hot days.

I am always impressed by the early engineering and construction skills of the Persians and these three structures are classic examples of their advanced thinking to the extent that countries today are looking to use these ideas as more sustainable alternatives to the energy-hungry modern equipment we currently use.

Not bad for a 2000 year old legacy.

Further reading:

The circle of ancient Iranian studies

Green Prophet

 

 

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