This photo was taken by the Phantom Golfer who has allowed me to use it here.
It is the mouth of a qasat, a type of structure used to tap the sub-artesian water supplies .
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I think that my favourite place in Iran is Yazd. The thought of dumping a group of people in the middle of a desert to do their own thing in the Sasanian Period and have them come up with such innovative solutions to the heat and lack of water is nothing short of astounding.
To begin with the people had to bring the water from the mountains, after which they worked out a system to cool it and then to turn it into ice and store it against the heat of summer.
The water was, and still is, carried from the mountains in ceramic pipes with a gentle downward flow and a series of wells at convenient intervals for maintenance.
This photo was taken by the Phantom Golfer who has allowed me to use it here.
It is the mouth of a qasat, a type of structure used to tap the sub-artesian water supplies .
To quote the Phantom Golfer:
"Some women were taking fresh water from near the opening and the channel carried on to a large concreted pool from where it could be drawn to water the nearby gardens and for stock use. I followed the course of the tunneling for some distance along the rising ground where, every fifty yards or so, there were earth and rock mounds where pits had been dug to allow the tunnellers to remove the waste material."
A very large wind tower
The use of wind towers for cooling intrigued me. These towers create eddies and these are very strong when one stands underneath the wind tower. Not only do they create a strong draught but some of the channels in the tower create an upward flow and others create a downward flow.
The tissue was sucked up into the tower via one conduit and a few seconds later returned via another
A tissue released underneath a large wind tower was sucked up and returned again with the downdraught. Wooden beams sticking out from the towers help to create the eddies on the outside. A pool of water underneath one of these wind towers acts as a primitive and very effective evaporative air cooler.
Cold winds are directed down the wall onto the water below
Also using shape to create air currents was the facility for making ice. Shallow pools were filled with water and the high wall behind these pools created a downward flow of air which, in the wintertime was cold enough to turn the water into ice. This was harvested and stored in icehouses which, when full, were sealed until the ice was needed in the hot summer.
The ice was stored in this dome-shaped building to be used in the summer
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