Pot-In-Pot Refrigerator

Zeer Pot-In-Pot Refrigerator An example of a pot-in-pot refrigerator.

The pot-in-pot refrigerator (also known as the zeer) was invented in 1995 by Nigerian teacher Mohammed Bah Abba. Its inspiration came from a growing need to keep food fresh longer in the small communities of third-world countries that have little to no electricity.

The design of the pot-in-pot refrigerator is a very simple one. In fact, you can build one at home! Here are some instructions:

  1. First, find a large earthenware pot; clay, not plastic. Pour a layer of sand at the bottom.

  2. Then place a smaller pot (approximately 1-2 inches less in diameter) inside of the larger pot, making sure that there is enough sand at the bottom so that the tops of the two pots are even.
  3. Fill the space between the two pots with sand.
  4. Pour water into the sand until it’s completely saturated.
  5. Place the food you wish to keep cool inside of the smaller pot and cover it with a damp cloth.
  6. Refill the sand with water at least twice a day and check the cloth regularly to make sure that it’s damp.

As the water evaporates from the sand, it absorbs the heat from inside of the smaller pot and carries it away. This is how the zeer functions as a small-scale refrigeration device. According to Science in Africa magazine, the zeer can keep vegetables such as tomatoes fresh for up to 20 days and meat can survive well for about a week. It won’t replace your kitchen’s refrigerator by any means, but it’s a fun experiment!