TU Graz 3D Prints Ceramic Cubes to Cool Rooms by Nearly 7°C, No Electricity Needed

Europe is living through its fourth major heatwave of the 2026 season, with temperatures above 40°C recorded across the Iberian Peninsula, France, Italy, and Austria. Cities are hit hardest: urban heat island effects can push local temperatures 1.7 to 4°C or more above surrounding rural areas. Against that backdrop, the Institute of Architecture and Media at TU Graz is testing a low-tech physical principle to cool buildings without drawing power. They’re leverage the power of evaporative cooling, delivered through 3D-printed, highly porous ceramic cubes. Another testament to how 3D printing can be used to create sustainable technology.

An up-close look at the 3D printed cubes.

What Is Evaporative Cooling?

When water evaporates, it draws heat from its surroundings, causing evaporative cooling. “[Evaporative cooling] has been working for centuries, both in clay jugs and in traditional wind towers,” explains Milena Stavric from TU Graz. “The key technological advance here lies in the use of 3D printing, which enables us to produce highly complex, porous and functionally optimised geometries from clay mixtures. These special structures store water particularly efficiently and, despite their small volume, create an enormous evaporation surface.”

The cubes, with sides of around 23 centimetres, are 3D printed from a ceramic clay mixture, then fired at low temperature to reach a highly porous consistency. Water is drawn into the porous ceramic by capillary forces and spreads evenly through the structure, creating a large surface over which it continuously evaporates, pulling heat from the surrounding air.