In the quest for sustainable architecture, researchers at ETH Zurich have taken a novel approach to indoor air quality management by harnessing the power of hygroscopic materials. Instead of relying solely on mechanical ventilation systems that often release moisture back into the environment, these innovative materials absorb excess humidity from indoor spaces, storing it temporarily until natural ventilation occurs. This method could be a game changer for high-traffic environments where traditional ventilation systems struggle to keep up.
Guillaume Habert, a Professor for Sustainable Construction and the project supervisor, emphasizes the practicality of this solution. “Our solution is suitable for high-traffic spaces for which the ventilation systems already in place are insufficient,” he notes. This is particularly relevant in today’s world where building occupancy rates are rising, and the demand for healthy indoor environments is at an all-time high.
The researchers focused on using finely ground waste from marble quarries, adhering to the principles of the circular economy. This waste material is combined with a geopolymer binder made from metakaolin and an alkaline solution, creating a robust building material that not only absorbs moisture but also boasts a significantly lower carbon footprint compared to traditional cement. The production process, spearheaded by Professor Benjamin Dillenburger, employs 3D printing techniques to create customizable wall and ceiling components. “This process enables the efficient production of sustainable components in a wide variety of shapes,” Dillenburger explains, highlighting the versatility of this approach.
The study led by building physicist Magda Posani demonstrated that these hygroscopic components can drastically improve indoor comfort levels. In simulations of a library reading room in Oporto, Portugal, outfitted with these innovative materials, the discomfort index—a measure of humidity-related discomfort—plummeted by 75% compared to conventional painted walls. Even more striking, increasing the thickness of the components from 4 cm to 5 cm could reduce discomfort by as much as 85%. This data is not just numbers; it underscores the potential for these materials to redefine how we think about indoor environments.
What’s more, these hygroscopic materials offer a climate-friendly alternative to conventional ventilation systems. Over a 30-year lifecycle, they emit significantly fewer greenhouse gases compared to systems designed to maintain optimal air quality. While traditional clay plaster has been a reliable method for humidity regulation, it lacks the water storage capacity of the newly developed materials. This positions the ETH Zurich research at the forefront of sustainable building technology.
As the construction industry grapples with the dual challenges of sustainability and occupant comfort, the introduction of moisture-buffering components marks a significant step forward. The successful proof of concept lays the groundwork for scaling this technology for industrial manufacture, potentially transforming the materials market. With increasing awareness of climate change and the importance of sustainable living, innovations like these could very well shape the future of building design, pushing us closer to a world where our indoor environments are not just livable but also regenerative.
