Using clay to cool things naturally is a low-tech method that's been known and used for centuries. Though clay has made an appearance in cool-looking refrigerator designs, Swiss designer Thibault Faverie's Cold Pot is a natural and simple air conditioner that uses clay and the power of evaporation to cool down temperatures in a low-tech energy-efficient fashion.
Created during his time at University of Art and Design Lausanne, Faverie explains how it works:
Cold Pot is a terracotta pot inspired by natural system to gradually lower the air temperature through the process of evaporation. Based on the 'bio air-conditioning', the porous terracotta surface acts as a heat exchange; it absorbs water from the inside and sends it to the outer surface. On contact with air, the water evaporates. The change from a liquid state to a gaseous one results in the cooling of the object and consequently the inner aluminum pipe, where air circulates.
So in addition to the nifty evaporative cooling function, the interior pipe contains aluminum "cooling slices" that are fanned by an small electric blower. Hot air comes in through a wide mouth in the pot's bottom and is cooled as it passes through the pot's interior pipe.This device is ultra low-maintenance, using only two litres (half gallon) of water to lower the temperature of the air 8 to 10 degrees Celsius (14.5 to 18 Fahrenheit), according to the designer.
While it probably won't cool very large spaces, Cold Pot is a no-frills but effective design that draws its inspiration from tried and tested traditional methods of keeping it cool. More over at Thibault Faverie's website.