The invention called “Pot-in-pot”Was developed by Mohamemed Bah Abba, resident of northern Nigeria where 90% of villages have no electricity. With this method, you can refrigerate food without consuming energy.

In 1995, Nigerian professor Mohammed Bah Abba designed a food refrigeration system that did not need electricity or fossil fuels to function properly. He is known as Pot-in-Pot and Zeer. Its design basically consists of two pots of porous material with sand between them, on which a damp cloth is placed.

Its principle of operation is evaporative cooling. As the water in the cloth evaporates, it absorbs energy (latent heat) from the inner container, which will stay cool while this process continues. Unfortunately, due to its design principle, the pot-in-pot only works in dry climates, because in humid climates water does not evaporate as needed.

How the pot-in-pot works.

It works very basic and involves placing a ceramic pot inside another larger pot, filling the space between them with wet sand and covering the top with a damp cloth. When the water evaporates, it extracts the heat stored inside the container with it, thus generating a decrease in the internal temperature. It is a natural process, inexpensive and easy to perform.

  1. Two clay pots are needed, one with a larger diameter and dimension than the other (space between them of one to three centimeters). Sand and water. the the pots will be terracotta or clay, without enamel.
  2. Fill in the holes at the bottom of the jars. Use clay, large stones, cork, homemade pasta; Whatever is appropriate available to fill the void. If you leave the holes open, the water will also go to the inner pot and be exhausted in the larger pot, making the system inefficient.
  3. Fill the bottom of the larger pot with coarse sand. Fill it to a height that ensures the smaller pot is at the same height as the larger pot. Place the small pot on the bottom layer of sand in the large pot.
  4. Fill all around the small pot with sand. Fill almost all the way, except to leave a small gap at the top.
  5. Pour cold water on the sand. Do this until the sand is completely soaked and cannot absorb any more water. As you pour in the water, do so gradually to allow time for the water to soak into the clay.
  6. Take a cloth or towel and immerse it in the water. Place the cloth on top of the inner container so that it covers it completely.
  7. Let the inner pot cool. Use a thermometer or your hands to check the cooling effect of the system.
  8. Store this refrigerator in a dry and ventilated place so that water can evaporate effectively to the outside.
  9. Place food inside to keep it. You will need to regularly check the humidity of the sand. Pour in more water as it gets drier to keep it really moist. Usually twice a day.

With this system, perishables that lasted only 3 days (before the decomposition process started) can now last up to 3 weeks.

Pot_in_pot_refrigerador_no electricity

With his invention he won the Rolex price which gives away $ 75,000 in prizes.

Brilliant ideas are not difficult to execute, here is a clear example. The technology has been known for centuries, but has never been applied to this problem.

Photography: AIDG Photo Stream.