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You may be happy with your current refrigerator but you would be happier with this power-less refrigerator. This refrigerator can keep your food fresh without any electricity. This Zeer pot-in-pot refrigerator requires only water, sand, and a hot, dry climate to preserve food through evaporative cooling. Here’s a small Do It Yourself guide to make this refrigerator.
Materials You Need
- A bag of sterile sand
- A trowel
- A square of burlap cloth large enough to cover the top of the inner pot
- 2 terracotta pots with a 2-3 inch difference in diameter. The smaller pot should be glazed and preferably lacking a drainage hole. If the inner container is double glazed (on its inner and outer walls) then non-potable water (eg, seawater) can be employed.
How To Build It?
- Make your pots drainage-proof. Cover drainage holes with cork or some waterproof material, otherwise will leak into the lower pot and will ruin the food.
- Make a one-inch deep layer of sand in the bottom of the large pot. Place the smaller pot on top of that layer and center it in the larger one. The small pot’s lip should be even with the larger one’s.
- Now fill remaining area between the pots with sand. Just leave about an inch of space below the lips of the pots.
- Now cool the pot by pouring cold water over the sand until it is thoroughly saturated. Place your food in the smaller pot and cover it with a burlap cloth soaked in water.
- Make sure to refill the water regularly, about once or twice a day.
How It Works?
A Nigerian school teacher, named Mohammed Bah Abba created The Zeer in 1995. It works on a simple principle. Water evaporating from the outer surface draws heat from inner one (as latent heat). The Zeer is capable of keeping 12kg of food fresh for three to four weeks without any electricity.
For this simple invention but a great idea, Bah Abba was awarded the $75,000 Rolex Award for Enterprise in 2000 and the World Shell Award for Sustainable Development in 2001 to help spur its development. Currently, he is selling around 30,000 Zeer per year for $1.30 each.
Why Is It Important?
Everybody knows how hot Africa is. And taking food from the place you produce to the market without any cooling equipment is a big challenge. Also the electricity supply is also not proper in many parts of Africa. In Sudan it is the responsibility of women to deliver the goods on time. This tight freshness deadline leaves little free time for their education. But if they had to go to market only weekly, rather than daily, they might actually have time for school.
The Zeer helps the complete Sudanese society. Farmers can preserve their produce. There have been fewer cases of food-borne illness. It can even be used to store water and temperature-sensitive medicines.
Even if you are not in Sudan or Africa, still the Zeer provides you electricity free refrigeration. Places where people face long power cuts, the Zeer turns into the hero to the rescue.