3D-printed wall panels absorb moisture, regulate humidity for healthier homes

In crowded indoor spaces, humidity can quickly rise, making the air feel stuffy and uncomfortable. Traditional ventilation systems combat this, but they consume energy and have an environmental impact.

Researchers at ETH Zurich have created new 3D-printed wall and ceiling coverings that naturally absorb and store excess moisture.

This innovative solution addresses high humidity by using a hygroscopic material that temporarily absorbs excess moisture from the air. This stored moisture is then released gradually when the room is ventilated, which reduces the need for constant mechanical dehumidification.

“Our solution is suitable for high-traffic spaces for which the ventilation systems already in place are insufficient,” says Guillaume Habert, Professor for Sustainable Construction, who supervised the ETH research project.

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3D-printed wall covering

This innovative building material utilizes finely ground marble quarry waste as its primary component.

To transform this waste into usable building components, a geopolymer binder was used. This binder, made from metakaolin and an alkaline solution, effectively binds the marble powder together, creating a solid and durable material.

The research team successfully produced a prototype 3D-printed wall/ceiling component measuring 20x20 cm and 4 cm thick.

Utilizing binder jet printing technology, the process involved layering marble powder and binding it together with the geopolymer solution.

“This process enables the efficient production of components in a wide variety of shapes,” said Benjamin Dillenburger.

Lower environmental impact

To assess the effectiveness of the hygroscopic components, a simulation was conducted in a virtual reading room in Oporto, Portugal. This simulation modeled a room used by 15 people, with its walls and ceiling entirely covered by the moisture-absorbing material.

The simulation aimed to determine how often and to what degree the humidity levels within the room exceeded the comfortable range (40-60% relative humidity) throughout the year.

Based on these findings, a "discomfort index" was calculated, which quantified the overall loss of comfort due to excessive humidity.

Using the hygroscopic components reduced the discomfort index by 75% compared to a standard painted wall.

Increasing the component thickness from 4 cm to 5 cm further improved performance and reduced the discomfort index by 85%.

“We were able to demonstrate with numerical simulations that the building components can significantly reduce humidity in heavily used indoor spaces,” said Magda Posani, a building physicist who conducted property analysis, in the press release.

Moreover, the study found that the 3D-printed hygroscopic components have a lower environmental impact compared to standard ventilation systems used for dehumidification.

Over a 30-year lifespan, these components hold the potential to generate substantially fewer greenhouse gas emissions.

This proof of concept demonstrates the technology's potential for further refinement and subsequent large-scale industrial manufacturing.

Switzerland's goal of achieving net-zero emissions by 2050 necessitates the construction of buildings that minimize greenhouse gas emissions throughout their lifecycle.

In the near future, architects can majorly reduce the need for energy-intensive mechanical ventilation systems by incorporating these coverings into building designs. On the other hand, it makes the indoor environment more comfortable for people, providing dual benefits.

The findings were published in the journal Nature Communications.