Pot-in-pot cooler
From Solar Cooking
I have been interested in solar cooking for a long time, but recently heard about a low-tech method for preserving food.
The ”pot-in-pot” cooler, based on by ancient techniques for cooling through evaporation, was designed by Mohammed Bah Abba who won the Rolex prize and who has been promoting this process though-out Nigeria.
I decided to make a “pot-in-pot” cooler and here are photos of it. The basic unit has two large unglazed pottery pots which I commissioned to be made without bottom holes by Panama Pottery in Sacramento. One pot fits inside the other with a layer of sand in between the pots.
I am using my watering pot here to wet the sand layer, which I do every morning. Inside the inner pot, there is a watermelon, a cabbage, a bag of carrots and two apples.
I have a folded towel on top of the pots and produce and I am wetting the towel to provide additional evaporation through the cloth top. I moisten the cloth twice a day.
Folsom, California, is typically hot in the summer, but this is an exceptionally hot day at 109 degrees in the shade. It is an excellent opportunity to test this cooler.
Here the temperature inside the pot is 74 degrees. It is 35 degrees cooler inside the pot than outside. I have now had these fruits and vegetables in the device for a week and they are perfectly fresh. The daytime outside temperature has varied this week from the high of 109 degrees to 90 degrees and the temperature inside the pot has varied from 75 degrees to 62 degrees.
If you would like to learn more about this device, go to http://www.rolexawards.com/laureates/laureate-6-bah_abba.html
