Cities are getting hotter, air conditioning is expensive to run, and every summer the grid groans a little louder. So when a university team builds a wall that cools the air around it by almost seven degrees Celsius using no electricity at all, just water and clever geometry, it is worth paying attention. That is exactly what researchers at Graz University of Technology (TU Graz) in Austria have done, and the tool that made it possible is a 3D printer.
A wall that drinks water and breathes out cold
According to the TU Graz announcement published on EurekAlert, the team at the university's Institute of Architecture and Media 3D printed cubes roughly 23 centimeters on a side from a ceramic clay mixture, then fired them at low temperatures to leave the material highly porous. Stack the cubes into a wall, add water, and physics does the rest: capillary forces pull water throughout each cube, the water evaporates off an enormous internal surface, and evaporation pulls heat out of the surrounding air.
The principle is ancient. Clay jugs and Persian wind towers have cooled water and buildings this way for centuries. What is new is the geometry. The team printed the cubes as triply periodic minimal surfaces, or TPMS, a class of mathematical shapes that pack a huge amount of surface area into a small volume using very little material. In a controlled test in a hot attic, a single water-filled cube dropped the nearby air temperature by almost 7 degrees Celsius, and a free-standing two by two meter demonstration wall now sits on the TU Graz campus where anyone can walk up and feel the effect.
The materials science gets even better. To boost porosity, the team mixed fungal cultures and sawdust into the clay. The mycelium grows a fine thread network through the material before printing, and when the part is fired, the organic material burns away, leaving behind a web of micro and macro pores that spread water through the cube like a wick. They are even testing dredged lake sediment from Lake Neusiedl as a printable building material that would otherwise be thrown away.
My electronics enclosure keeps overheating. Can 3D printing actually help with cooling?
Yes: 3D printing lets you build cooling features directly into a part, things like internal channels, pin fin arrays, and high surface area lattice walls that molded or machined enclosures simply cannot have. The TU Graz project is a perfect illustration of the underlying rule: heat transfer scales with surface area, and additive manufacturing is the only production method that lets you multiply surface area inside a fixed footprint without assembly. For an enclosure that runs hot, that can mean printed vent geometry tuned to airflow direction, a lattice section where a solid wall used to be, or standoffs and ducting that guide air exactly where the heat source sits. If you have a specific part fighting heat, send it to us through our build and ship service and we will look at the thermal problem before we quote the print.
The geometry is the product
Here is the part of this story we keep coming back to. TU Graz did not invent a new refrigerant or a new compressor. They took clay, one of the oldest building materials on Earth, and made it dramatically better at an old job by changing its shape at a scale only a 3D printer can produce. The cube is not impressive because of what it is made of. It is impressive because of how it is arranged.
That same logic shows up all over modern engineering: heat exchangers with TPMS cores, lightweight aerospace brackets, catalyst substrates, acoustic panels, impact absorbing lattice cushions. In every case the material is ordinary and the geometry is doing the work. For engineering buyers, that reframes what you are actually purchasing when you order a printed part. You are not paying for plastic or ceramic by the kilogram. You are paying for arrangement.
I need a part with internal channels no machine shop can make. Is 3D printing my only real option?
For truly internal geometry, sealed channels, lattice cores, and curved passages with no straight line tool access, yes: 3D printing is generally the only practical way to make the part in one piece. A machinist needs a path for the cutter, and a mold needs a way to eject the part, so both processes hit a hard wall when the feature lives entirely inside the volume. Printing builds the part layer by layer, so an internal passage costs nothing extra. We produce parts like this every week, including in high temperature polymers, through our PEEK and ULTEM printing service, for customers who need performance in hot, demanding environments.
One note for fellow reviewers of the industry: if you are a brand building cooling hardware, lattice software, or printable technical materials and you would like an honest hands-on review from a working print shop, reach out at info@dcadditivepros.com. We test on real machines and say what we find.
Frequently asked questions
What is a TPMS lattice and why does it show up in every cooling design?
A TPMS lattice is a repeating mathematical surface that packs the maximum surface area into a volume with smooth, continuous walls, which is exactly what heat exchange and evaporation need. Gyroids are the most famous example, and slicers already use them as infill because they are strong in every direction and print without supports.
Can you 3D print a part with internal channels that can't be machined?
Yes, internal channels are one of the main reasons to choose 3D printing over machining, because the printer builds the cavity as it builds the part. No tool access is needed, so curved, branching, or sealed internal passages print in one piece.
Does evaporative cooling really work without any electricity?
Yes, evaporative cooling is pure physics: when water changes from liquid to vapor it absorbs heat from its surroundings, no power required. The TU Graz test measured a drop of almost 7 degrees Celsius near a single water-filled ceramic cube in a hot attic. It works best in dry air, which is why the approach comes from hot, arid regions.
Can DC Additive Pros print parts for hot environments?
Yes, we print high temperature engineering polymers including PEEK and ULTEM, which are used in aerospace, energy, and industrial applications where standard plastics fail. Tell us the temperature and load the part actually sees and we will recommend a material honestly, including telling you when a cheaper material is enough.
DC Additive Pros is an independent 3D printing shop in Rockville, MD. We are not affiliated with, sponsored by, or endorsed by Graz University of Technology, TU Graz, or EurekAlert. All trademarks belong to their respective owners.