A zeer pot is simply an electricity-free “fridge” for vegetables. It works through evaporative cooling. You have one smaller terracotta pot nestled inside another and a barrier of wet stand between them. This sand acts as a wick to move moisture up the pot walls. It doubles as a thermal mass to keep the pot cool once its temperature starts to drop. You just put it in a shady, breezy location, and wait for it to cool. It is similar to the effect of stepping out of a swimming pool wet and getting struck by the wind. Imagine how cold you’d get if you let that go on for hours.
Zeer pots work similarly to refrigeration solutions which were pioneered in ancient times before human beings discovered how to use electricity. Today they are used mainly in Third World countries. They can extend the life of vegetables from days to weeks, which helps to counter the hunger problem.
You can learn how to make your very own zero-electricity zeer pot out of simple materials on Instructables here.
There are a lot of steps, but there are pictures for each, so it is easy to follow. I have always been very curious how you can keep food cool without electricity, so purely from a science perspective, this project is utterly fascinating to me. But it is a great way to reduce your ecological footprint and cut your energy bills as well. I am definitely going