How to build a Zeer pot
What is an evaporative refrigerator?
It is a device that uses the evaporation to cool a space that can be used to store food or water. An illustration of one version is shown at right. This version was created by putting one earthenware pot inside another, filling the space between them with sand and then wetting the sand. Food is stored in the inner pot which can be covered by a wet towel or a lid. As the water evaporates from the sand, it cools the inner pot and its contents. The whole thing is easy to build and to operate and, best of all, it is inexpensive. An added bonus is that the water used for cooling does not need to be potable. That sounds perfect for third world applications and it is most often in this context that the device is discussed.