How To Make an Electricity-Free Refrigerator

Conventional refrigeration does an incredible job keeping food fresh. But that technology hasn't helped desert dwellers without steady electricity. A more recent development in refrigeration—the Zeer pot-in-pot refrigerator—only requires water, sand, and a hot, dry climate to preserve produce through evaporative… » 8/27/12 10:00am 8/27/12 10:00am