Researchers at ETH Zurich have developed an innovative, moisture-binding building material that has the potential to revolutionize indoor climate control, significantly reducing energy consumption and greenhouse gas emissions.
A team of researchers at ETH Zurich has unveiled a pioneering moisture-binding material designed to passively regulate indoor humidity, promising significant advancements in sustainable building technologies. This breakthrough, published in the journal Nature Communications, could drastically reduce reliance on energy-intensive mechanical ventilation systems, fostering a more eco-friendly approach to indoor climate control.
Whether in offices, museums or public waiting areas, crowded spaces often suffer from heightened humidity levels, leading to discomfort. Traditionally, mechanical ventilation systems have been employed to manage this issue, albeit with considerable energy consumption and a carbon footprint.
Seeking a greener solution, ETH Zurich researchers focused on a material that absorbs moisture through walls and ceilings, storing it temporarily instead of expelling it through mechanical means.
“Our solution is suitable for high-traffic spaces for which the ventilation systems already in place are insufficient,” Guillaume Habert, a professor for sustainable construction at ETH Zurich who supervised the project, said in a news release.
Waste Marble Powder Finds New Life
Emphasizing circular economy principles, the researchers utilized finely ground waste from marble quarries as the base material. They then employed a geopolymer binder — comprising metakaolin and an alkaline solution — to convert this powder into solid moisture-binding components via 3D printing techniques.
The ETH project successfully produced a prototype component measuring 20 x 20 cm and 4 cm thick. The 3D printing process allows for efficient manufacturing of various shapes, as noted by Benjamin Dillenburger, a professor for digital building technologies, who led the 3D printing production group.
“This process enables the efficient production of components in a wide variety of shapes,” Dillenburger said in the news release.
Enhanced Comfort and Sustainability
Magda Posani, now a professor at Aalto University in Finland, led the study of the material’s hygroscopic properties.
The team conducted numerical simulations to validate their findings, focusing on a public library reading room scenario in Oporto, Portugal. The results showed that these hygroscopic components could reduce the discomfort index by 75% when compared to conventional painted walls, and up to 85% with slightly thicker components.
“We were able to demonstrate with numerical simulations that the building components can significantly reduce humidity in heavily used indoor spaces,” Posani added.
A Greener Future
Beyond enhancing occupant comfort, these components offer a climate-friendly alternative to traditional dehumidification methods. Over a 30-year lifecycle, the new material emitted significantly fewer greenhouse gases compared to conventional ventilation systems. While clay plaster — a traditional method — proved even more climate-friendly, it lacks the same water vapor storage capacity.
Having confirmed the proof of concept, the research team is optimistic about scaling up the technology for industrial use. They continue to collaborate with institutions like Turin Polytechnic and Aalto University to further reduce the greenhouse gas emissions of these building components.
As Switzerland aims for its net zero target by 2050, the adoption of sustainable building materials becomes crucial, the researchers noted.