Sustainable Refrigerator

The Sustainable Refrigerator is ‘powered’ by dirty water. The prototype consists of two metallic cylinders, one inside the other, between which a locally-sourced material such as sand or wool is packed tightly before being soaked with water.
When the fridge is placed in a warm environment, the sun’s energy causes the outer part of the fridge to ’sweat.’ Water evaporates from the sand or wool and heat energy is transferred away from the inner cylinder, which becomes cooler. The design does not require electricity and can be built using barrels, spare car parts and ordinary household materials.
The contents of the fridge are kept dry and hygienic because the water does not come into contact with the product.