What is the meaning of Yakhchāl?

A yakhchāl ("ice pit"; yakh meaning "ice" and chāl meaning "pit") is an ancient type of ice house, which also made ice. They are primarily found in the Dasht-e Lut and Dasht-e-Kavir deserts, whose climates range from cold to hot desert regions.

In present-day Iran, Afghanistan, and Tajikistan, the term yakhchāl is also used to refer to modern refrigerators.

The structure typically had a domed shape above ground, a subterranean storage space, shade walls, and ice pools. It was often used to store ice, but sometimes was used to store food as well as produce ice. The subterranean space and thick heat-resistant construction material insulated the storage space year-round. These structures were mainly built and used since ancient times in Persia.

A yakhchāl's engineering is optimized to take advantage of the physics of evaporative cooling and radiative cooling, and the fact that the arid, desert climate is low in relative and absolute humidity.The low relative humidity increases the efficiency of evaporative cooling due to the vapor pressure differential, and the low absolute humidity increases the efficiency of radiative cooling because the water vapor in the air otherwise inhibits it. In addition, in some desert climates, like those at high altitudes, temperatures drop below freezing at night. Their design is generally split into three areas: the ice house or reservoir, the shade walls, and the ice pits or pools.