How Ancient Persians Made Ice in the Desert With No Electricity

How did ancient Persians make ice in a desert that hit 50°C, with no electricity and no machines? The building is called a yakhchal — Persian for ice pit. The ice was not made inside it. It was made in a shallow pond, at night, under a dry sky, behind a wall tall enough to hold off the winter sun. Then it was carried into a cone of mud, lime, ash, and goat hair, and kept through a summer that should have destroyed it. This is the full system: the pond, the wall, the qanat, the dome, and the chimney that was never a chimney. 0:00 The Impossible Ice in the Desert 2:30 The Secret of the Shallow Pond 6:12 Inside the Ancient Ice Pit 8:36 The Physics of the Solar Chimney 12:50 A Full Year of Desert Engineering #Yakhchal #AncientEngineering #AncientPersia