But such is the ingenuity of our ancestors that they managed to come up with ways to survive without such appliance. Around 4th century B.C., ancient Persians already have their own “refrigerator” in the form of a building called yakhchāl.
It’s not actually surprising that Persians came up with something like this, considering that they are one of the cradles of civilization.
The yakhchāl looks like a burial ground at first look, but it was actually an “ice pit” where Persians can store their food during the summer months.
Given the excessive heat and arid climate of the region, the yakhchāl was indeed a tremendous help for the people.
Inside the domed structure was an evaporation cooler system that kept the perishables to stay cool or frozen while stored underground.
So how did the Persians manage to get ice in the structure? The cooling system worked through windcatchers and water fetched from nearby springs via qanāts, which are underground channel systems designed to bring water through communities and facilities.
The system allowed decreased temperatures to develop inside the yakhchāl.
The walls of the structure were built using a special type of mortar that brought insulation from the desert climate.
The mortar was composed of an interesting mix of components such as sand, clay, egg white, and goat hair.
The yakhchāl also had trenches at the bottom that collected water coming from molten ice. The water gets refrozen at night, contributing to the cold inside the structure.
The system is not being used anymore although some of the yakhchāls can still be seen across Iran and a number of its neighboring countries.