This Beautiful A/C System Works Without Electricity

By Jesus Diaz

An architect in India used age-old principles to design an alternative to A/C–desperately needed as global temperatures rise.

A new terracotta device can turn hot air into a cool breeze, pushing temperatures inside a room from over 107 Fahrenheit down to 97. According to its creator—Monish Siripurapu, founder of the Indian architectural firm Ant Studio—it works using hundreds of terracotta cones, wind, water and magicks!

The magic part is actually science as old as civilization itself: Using clay and the evaporation of water to cool things down is an ancient method that has been used in various forms through the ages. In India and Pakistan there’s evidence of clay pots used to cool water around 3000 BC, which has continued until today. Around 2500 BC, in Egypt’s Old Kingdom, slaves used to fan clay jars to accelerate the evaporation process, quickly cooling the water inside.

Ant Studio used this same principle to create this clay beehive (which may trigger a bad case of trypophobia in some people) using computers and mathematical models.

Their system runs water down the structure, which soaks the terracotta. Then, as the hot air passes through the cones, the humidity in the clay captures part of the heat stored in the air, cooling it down as the water evaporates through the pores of the material. The results are remarkable: They recorded air going into the system at 122 Fahrenheit at a speed of 10 meters per second. The cooled air came out going 4 meters per second on the other side, pushing the temperature inside the building all the way down to a still hot but acceptable 96.8 Fahrenheit.

That differential may not sound like a lot, but in hot areas of India, where deadly heat waves are getting worse, that change is quite significant. The fact that it doesn’t require much maintenance and doesn’t eat electricity like a power-hungry A/C unit makes this a nice cooling solution for sustainable development.

The installation cost is lower than industrial A/C machinery. Siripurapu told me in an email that the total price tag is roughly $1,850. If you factor in maintenance, the price differential over time is huge. Monish says they didn’t design the current prototype for residential use, however: “The solution is scalable and currently we are working factories to implement this idea. We have not tested this idea for residences. We are working on it.”

He added that it might not be best possible solution in places like residences and indoor areas where there is no wind flow: Like the Egyptians with their fanning slaves, this system needs wind to work. For this test, Ant Studio used a generator to push the hot ambient air into the cones. But even if you count the cost of electricity of running a fan in places with no wind flow, the power consumption will still be much lower than an A/C system.

Another bonus: Siripurapu believes that the system would benefit local pottery makers, who make the terracotta pieces necessary to build it.