Based on the ancient Egyptian technology known as “evaporative cooling,” New Delhi-based Ant Studio created a zero-electricity, zero-emissions air conditioner made simply of terra-cotta tubes and water. Inspired by the structure of a beehive, the cone-shaped clay tubes stacked on top of each other in alternating directions.
When water runs down the structure—it’s sufficient to wet the cones just once or twice a day—the process of evaporation gradually lowers the air temperature. The porous terra-cotta units absorb water that then seeps to the outer surface, where it evaporates and turns into cold air.
https://returntonow.net/2018/07/17/natural-air-conditioner/