The Yakhchāl an ancient Persia refrigeration

Ancient Ice-Making Machines Found In Persian Desert, The Yakhchāl

This is a Yakhchāl, and ancient Persia refrigerator. Invented around 400bc. It used a cooling system that kept ice frozen all year round. The Yakhchāl is found in Iran where the climate enables ice to freeze on site in winter or where ice and snow could be brought from nearby mountain areas.
The ice has been reported to have been used for the production and preservation of foods and drinks in Summer and perhaps on occasion to be used for cooling buildings.

Yakhchāl in Persian means “ice pit”.
Yakh meaning “ice”
and chal meaning “pit”
…and its an ancient type of evaporative cooler.
Above ground the structure has a dome shape, with a large subterranean storage space. The use of thick heat resistance construction materials insulates the storage space year around. Cold air is allowed to pour in from the base of the structure, and descend to the lowest parts. At the same time the total conical shape of the building sends the remaining heat upwards and outside through openings at the very top of the buildings. Through this active process the air inside the Yakhchāl remains cold enough to have ice frozen in the scorching desert heat.

ICE MAKING PROCESS The ice is made in a shallow pond which is filled each night from a fresh water canal. A shading wall shield the pond from the heat of the low angle winter Sun. The water freezes from the low winter nights. Ice is harvested from the pond and is transferred to the Yakhchāl ice store. These type of Yakhchāl’s are reported to be constructed from locally sourced adobe containing sand, clay, egg white, goat hair, lemon juice, ash and a water resistant type of morter called Serruge.

In summer some sources claimed that dome was covered in a thick layer of straw thatch to insulate them from the heat of the Sun.
There are records and illustrations of their use in history. There are 129 Yakhchāl’s remaining today in Iran.