‘Refrigerator’ Without Electricity

Posted on April 3, 2008  Comments (3)

photo of pot in pot

2000 Rolex award to Mohammed Bah Abba of Nigeria for the Pot in Pot Cooling System:

Ingenious technique that requires no external energy supply to preserve fruit, vegetables and other perishables in hot, arid climates. The pot-in-pot cooling system, a kind of “desert refrigerator”, helps subsistence farmers by reducing food spoilage and waste and thus increasing their income and limiting the health hazards of decaying foods. Abba says he developed the pot-in-pot “to help the rural poor in a cost-effective, participatory and sustainable way”.

The pot-in-pot consists of two earthenware pots of different diameters, one placed inside the other. The space between the two pots is filled with wet sand that is kept constantly moist, thereby keeping both pots damp. Fruit, vegetables and other items such as soft drinks are put in the smaller inner pot, which is covered with a damp cloth. The phenomenon that occurs is based on a simple principle of physics: the water contained in the sand between the two pots evaporates towards the outer surface of the larger pot where the drier outside air is circulating. By virtue of the laws of thermodynamics, the evaporation process automatically causes a drop in temperature of several degrees, cooling the inner container, destroying harmful micro-organisms and preserving the perishable foods inside.

He also received the 2001 Shell Award for Sustainable Development. Great stuff:

Born in 1964 into a family of pot makers and raised in the rural north, Mohammed Bah Abba was familiar from an early age with the various practical and symbolic uses of traditional clay pots, and learned as a child the rudiments of pottery. Subsequently studying biology, chemistry and geology at school, he unravelled the technical puzzle that led him years later to develop the “pot-in-pot preservation/cooling system”.

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3 Responses to “‘Refrigerator’ Without Electricity”

  1. Ajith Edassery
    August 2nd, 2008 @ 10:20 am

    I hit this site accidentally and found this topic. In my childhood days, my dad, who was a government servant with the role of helping village development used to distribute this stuff among villagers. Even we had one like this at home.

    Btw, I am from India and was raised in a village place before moving to the city of Bangalore several years back. So this technology was prevalent in India as well…


  2. Brian
    December 19th, 2008 @ 2:16 pm

    It is a brilliant device, wich can provide indispensable assistance for people of India. Wich refrigerator can you advice for domestic use.

  3. Curious Cat Science and Engineering Blog » Student Invents Solar-Powered Fridge
    January 23rd, 2009 @ 12:42 pm

    […] Refrigerator Without Electricity – Compressor-free Refrigerator – posts on appropriate engineering – UK Young Engineers Competitions […]

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