The Clay pot cooler. I have loved this idea since my early twenties when I was first introduced to the concept of cooling food using a material I love, ceramic. I was excited by the idea of refrigeration without having to use electricity after I had lived for a year without any power or running water. We used to have to buy ice and put it in a Coleman cooler to keep any perishables fresh. It was smelly, messy and needed a constant source of ice which was heavy to carry. The concept of the clay cooler is simple, a porous outer earthenware pot, a smaller inner pot and wet sand filling the gap between the two layers. The evaporation of the water from the outside surface draws heat from inside.
These clay coolers have been used since ancient times. Egyptian frescos from around 2500 B.C. depict people fanning clay water jars which would have increased the air flow to cool the contents of the jars. I always knew there would be a way to mass produce this low tech idea to give people who did not want to or could not pay for electricity a means to store food, medicines, and other perishables.
The best version yet in my mind is by Prajapati Mansukhbhai Raghavjibhai, an entrepreneur who developed the Mitticool, a ‘fridge’ based on the same technology as the clay pot coolers.
“Water from the upper chambers drips down the side, and gets evaporated taking away heat from the inside , leaving the chambers cool. The top upper chamber is used to store water. A small lid made from clay is provided on top. A small faucet tap is also provided at the front lower end of chamber to tap out the water for drinking use. In the lower chamber, two shelves are provided to store the food material. The first shelf can be used for storing vegetables, fruits etc. and the second shelf can be used for storing milk etc. Cool and affordable, this clay refrigerator is a very good option to keep food, vegetables and even milk naturally fresh for days.”
The Gujarat Earthquake of 2001 inspired his innovation. ”Journalists came and photographed our broken matkas (water storage coolers). They referred to them as the poor man’s fridge. I thought why can’t we make a real fridge with the same cooling principle?” After four years of research he discovered an unusual combination of sawdust and sand added to the clay which made it porous and the interior cooler. The Mitticool also preserves the original taste of fruits and vegetables, is affordable, and does not require any maintenance costs.
Prajapati has also created a low cost ceramic water filter, a non stick clay Tawa (low tech teflon pan) and will likely continue to innovate new ways for low income people to have modern conveniences that help them to stay healthy. Take a moment to meet the man behind the dream in the INKtalk video.