Strangely the magnificent refrigerator in ancient times

Many people think that the refrigerator is the scientific achievement of the 20th century. Few people know that the refrigerator has existed since ancient times, since 400 BC.

In 400 BC, Persian engineers mastered the stone storage technology in the middle of the summer in the desert. The ice is brought in winter from the mountain and stored in the Yakhchal, also known as the ice tunnel. These ancient ice "refrigerators" were used for the purpose of storing ice and food for summer use. In addition, these ice sheets were used to treat the royal members.

Yakhchal - ancient refrigerator of Persians.

A floating structure, ice tunnel - 'refrigerator' is made up of a mud-brick composite, dome-shaped. It reached a height of about 18m. In the cellar, people dig a hole deep underground, about 5000 m ³ wide, for storage. Yakhchal has mud-brick walls up to 2 meters thick on the ground, made up of a mixture of sand, clay, egg white, lemon, goat fur, and ash with a moderate ratio. This mixture works against heat transfer and waterproof.

Yakhchal works as follows: a ganat, an underground system of ditches, moves water to the ice tunnel, where it freezes at night. Later, these ice sheets were crushed and stored in separate cabinets where they could easily be moved when needed.

Most yakhchal have a wall built in the south to avoid the sun and keep the ice shed always shady.

Many yakhchal operate on a slightly different principle. Large ice sheets are moved from the mountains down in winter and stored in ice tunnels. When the ice is melted, the ditches in the basement will keep that water, and this water will freeze back at night, easy for transport.

Yakhchal drawings.

In the tunnel, people dig a hole deep underground, about 5000 m ³ wide for storage.

The space inside the yakhchal.

Most yakhchal have a wall built in the south to avoid the sun and keep the ice shed always shady. High towers, called Badgirs , are used in ventilation systems. By circulating hot air from the ground and cold air from the ice tunnel, badgirs act as a thermostat, regulating the internal temperature of the yakhchal.

These yakhchal forms are found in much of Iran today.