There is also pot in pot refrigerator (http://en.wikipedia.org/wiki/Pot-in-pot_refrigerator http://en.wikipedia.org/wiki/Pot-in-pot_refrigerator) based on evapo

There is also pot in pot refrigerator (http://en.wikipedia.org/wiki/Pot-in-pot_refrigerator http://en.wikipedia.org/wiki/Pot-in-pot_refrigerator) based on evaporative cooling, which does not use electricity. Although it will not work well in humid places, it is still a much cheaper option.