Evaporative cooling was used as early as the Old Kingdom of Egypt, around 2500 B.C. As you can imagine, a clay pot cooler does not use electricity. It uses a porous clay pot (filled with wet sand) containing another smaller inner pot (which can be treated to prevent penetration by the liquid) within which the food is placed. The evaporation of the outer water draws heat from the inner pot.
Mansukhbhai Prajapati, an Indian rural innovator, was inspired by this concept and created the Mitticool. His objective was to create “A fridge for the common man that does not require electricity and keeps food fresh too.”It works with the same principle described before, evaporation. Water from the upper chambers drips down the side and gets evaporated taking away heat from the inside, leaving the chambers cool.
The top upper chamber is used to store water. A small lid made from clay is provided on top. A small faucet tap is also provided at the front lower end of the chamber to tap out the water for drinking use. In the lower chamber, two shelves are provided to store the food material.
The Mitticool looks have a really nice design and it is for sale at a reasonable price. However, you can make your own Pot in Pot cooler. You will just need two clay pots, a couple pounds of sand and water. Check out this 2-minute tutorial!