Clay has been used to cool things in a natural way for a long time, and recently the Swiss designer Thibault Faverie has created a simple, natural air conditioner from this material. His creation is called Cold Pot, and it utilizes clay and natural evaporation to lower temperatures in a very energy efficient and sustainable way. The unit is also very aesthetic, and looks much like a plant pot.
The Cold Pot is basically a terracotta pot with a porous surface that acts as a heat exchange, with an aluminum pipe to transfer the air and a fan to move the air through the air conditioner. The Cold Pot works by absorbing water from the inside and sending it to the outer surface. Once it comes into contact with the air, this water evaporates, and it is this change from a liquid to a gaseous state that cools the inner aluminum pipe, where air circulates inside the pot.
Apart from the natural evaporative cooling function, the interior pipe of the Cold Pot also contains aluminum “cooling slices,” which are fanned by an electric blower. There is a wide mouth in the bottom of the pot through which the air passes and where it is cooled. According to Faverie, this natural air conditioner requires very little maintenance, since it uses only two liters (approximately half a gallon) of water to lower the temperature of the air to 8 to 10 degrees Celsius (14.5 to 18 Fahrenheit). The Cold Pot is of course powered by electricity, but it uses a lot less power than your regular AC unit.
Due to its relatively small size, the Cold Pot can’t really be used to cool very large spaces. Though it could conceivably work very well to cool a tiny home, while there’s always the option of using more of them to cool a room. Either way, the idea is very green and sustainable, and a great example of using traditional knowledge in modern designs. More information about the Cold Pot can be obtained from Thibault Faverie’s website.