TU Graz 3D-Printed Ceramic Cubes Cool Rooms by 7C Without Electricity

Researchers at Graz University of Technology have turned an ancient cooling trick into a modern 3D-printed solution. Their system uses porous ceramic cubes, printed layer by layer, to cool indoor spaces by almost 7 degrees Celsius without drawing a single watt of electricity.

How It Works

The principle is evaporative cooling, the same process that keeps clay jugs cool in desert climates. Water evaporates, and as it does, it pulls heat from the surrounding air. The innovation at TU Graz is in the geometry: 3D-printed ceramic cubes with a highly porous, minimal-surface structure that stores water efficiently and exposes it to air across a massive internal surface area.

The cubes measure roughly 23 centimeters on each side. They are 3D-printed from a ceramic clay mixture using a TPMS, or triply periodic minimal surface, geometry. After printing, the cubes are fired at low temperature to achieve a porous consistency. Water enters the ceramic by capillary action and spreads evenly through the complex internal structure. From there, it continuously evaporates, drawing heat from the room.

Tested in a Hot Attic

The team placed a water-filled cube in a hot attic during a controlled test. The measured temperature drop in the immediate vicinity was nearly 7 degrees Celsius. Kristijan Ristoski, who wrote his master's thesis on integrating the cubes into a functional cooling wall, said the cooling effect was clearly noticeable throughout the room.

A free-standing, two-by-two-meter demonstration wall made from these cubes is now installed at TU Graz's Campus Neue Technik. A separate display at the city's Museum of Perception lets visitors experience the cooling effect firsthand.

Bio-Inspired Variant Uses Fungus

The research team is already pushing the concept further. In their Shape Lab, they are testing a bio-inspired variant: fungal cultures and sawdust are added to the clay mixture before printing. The mycelium grows into the material, forming a network of filaments. When the cube is fired, the mycelium and sawdust burn away, leaving behind micro- and macro-pores that spread water even more effectively through the structure.

The team is also experimenting with sediment from Lake Neusiedl, which has to be dredged regularly to prevent silting. Instead of disposing of the material, they are testing it as a 3D-printable building material. If it works, the cubes could be made from locally sourced waste sediment while solving two environmental problems at once.

Why This Matters for 3D Printing

Most 3D printing coverage focuses on mechanical parts, prototypes, or end-use production parts. This project is different: it uses 3D printing to create functional geometries that could not be manufactured any other way. The TPMS structure is the real innovation, and 3D printing is the only practical way to produce it at scale.

The cubes are positioned as an alternative to energy-intensive air conditioning in homes, offices, schools, and public spaces. In cities where urban heat island effects push temperatures well above surrounding rural areas, passive cooling systems like this could reduce electricity demand during peak summer months.

The project was funded by Austria Wirtschaftsservice GmbH as part of its proof-of-concept program. The team is open to contact from planners and companies interested in evaluating the technology for real-world projects.