Mohammed Bah Abba made a really cool invention, which won a Rolex Award of $100,000 –a refrigerator than runs without electricity. Here’s how it works. You take a smaller pot and put it inside a larger pot. Fill the space in between them with wet sand, and cover the top with a wet cloth. When the water evaporates, it pulls the heat out with it, making the inside cold. It’s a natural, cheap, easy-to-make refrigerator.
Evaporative fridges are a relatively well-tested, proven, low-tech approach to cooling. They can cool produce, food and beverages at about 15-20 C below ambient temperatures. They are most appropriate in hot, dry (not humid) climates.
That was a very nice article, with some really cool stuff…
The design of the refrigerator is VERY similar to Kimchi pots in Korea, where a large earthen pot is burried 80-90% in the earth with various vegetables inside fermented in various liquids. In this case, the ground serves as the main pot, and the earthen pot inside as the wet sand… Koreans have been using these for over a thousand years. 🙂
Also, I was surprised not to see this solar stove included…
http://www.youtube.com/watch?v=tH48iHBGc-0
http://manybooks.net/titles/jonessteetext04cookr11.html