3D Printed Ceramic Walls Explore Low-Energy Urban Cooling

Researchers at Graz University of Technology (TU Graz) have developed porous ceramic cubes that use evaporative cooling to reduce temperatures. Designed for indoor spaces and outdoor areas, the system combines traditional cooling principles with 3D printing. It could offer architects and landscape designers a way to provide local cooling in buildings and public spaces.

Porous Ceramics And Evaporative Cooling

The project, led by TU Graz’s Institute of Architecture and Media, builds on a principle used for centuries in clay vessels and traditional wind towers. As water evaporates, it absorbs heat from its surroundings, cooling the nearby air.

Each cube measures approximately 23 centimetres across. The researchers digitally design and print the components from a ceramic clay mixture, then fire them at low temperatures to retain high porosity.

A triply periodic minimal surface (TPMS) geometry creates a large surface area with relatively little material. Capillary forces draw water into the porous ceramic and distribute it throughout the structure. The extensive evaporation surface allows water to evaporate continuously and remove heat from the surroundings.

The team produces the cubes in its Shape Lab using a printer it developed and built. Called A.R.G.O.S. 140200, it can print complex components from earth-based materials, including clay, up to 140 by 200 centimetres.

Fungal Networks And Alternative Raw Materials

To improve water distribution and cooling performance, the researchers are experimenting with fungal cultures and sawdust in the clay mixture. The sawdust provides nutrients for mycelium, which forms a fine network within the material.

During firing, the mycelium and sawdust burn away, leaving micro- and macro-pores. These pores help water spread through the ceramic. The finished components therefore use fungi to create porosity rather than retaining living mycelium.

The team is also investigating sediment from Lake Neusiedl as a potential printing material. Regular dredging helps slow the lake’s silting, but much of the removed sediment currently goes unused. Incorporating it into construction materials could provide a useful outlet for this resource.

Early Results And Potential Applications

In a controlled experiment in a hot attic at TU Graz, researchers measured a temperature reduction of almost seven degrees Celsius immediately around a water-filled cube. The team also reported a noticeable cooling effect across the room.

Potential applications include homes, offices, schools, waiting areas and public spaces. A freestanding demonstration wall measuring two by two metres stands on TU Graz’s Neue Technik campus. The technology is also on display at Graz’s Museum of Perception.

Further Testing And Development

TU Graz reports around 100 serious enquiries from potential collaborators, businesses, municipalities and individuals. The institute is assessing further development and possible commercialisation.

Research continues into outdoor cooling capacity, with microbiological studies also planned. The next wall will incorporate solar panels to power its small water pump.

Austria Wirtschaftsservice funded the proof-of-concept project, which involves TU Graz’s building physics and environmental biotechnology institutes and HTBLVA Graz Ortweinschule.

Source & photos: TU Graz