Researchers in Germany are developing new wall materials which are capable of keeping indoor humidity levels at bay in order to create healthier indoor environments for occupants and prevent the formation of mildews or moulds.

Paint manufacturer Keimfarben GmbH teamed up with Bayreuth University and the Fraunhofer Institute for Silicate Research ISC to develop additives for paints and plasters which are capable of altering the air quality of indoor environments, with a particular focus on humidity levels.

They discovered that the addition of porous, flake-shaped glass particles to plasters enables them to significantly alter indoor humidity levels due to the ability of the adulterating material to rapidly capture and retain moisture in the air before releasing it slowly.

porous glass

The researchers used Vycor glass in the development of the humidity-changing plaster, as the specific parameters of the material can be precisely controlled during the manufacturing process.

The glass particles can be manufactured in the form of spheres, fibres or flakes, while the porosity and pore size of the material can be adjusted in order to control its effect upon atmospheric humidity. Minor changes in pore size can significantly alter the humidity absorbing propensity of the glass, enabling the researchers to adapt the material to different indoor conditions.

This is a critical advantage that the glass particles possess as an artificially manufactured material. Other materials which possess similar absorption properties, such as zeolite and ceramic, are not amenable to such precise adjustment and control.

Testing of plasters embedded with the glass flakes showed that the mixtures were capable of absorbing far more moisture than other materials traditionally used for curing humidity, such as zeolite and fibreboard, as well as other benchmark plasters. The glass-flake plasters also rapidly increase in mass following gains in humidity, attesting to their ability to absorb greater amounts of moisture.

According to Ferdinand Somorowsky, a researcher from the Fraunhofer institute, when added to the walls of room with a volume of 30 cubic metres and 40 square metres of surface area, the material should be capable of absorbing more than half a litre of water from the indoor atmosphere – more than enough to achieve a near-total reduction in humidity levels.

The materials could have major benefits for indoor environments and their occupants. In addition to making rooms more comfortable and pleasant by reducing stifling levels of humidity, they can also prevent the growth of mildew and moulds on walls by depriving them of moisture. These wall-crawling fungi are more than mere eyesores for indoor settings – they are also a key source of respiratory ailments for the regular occupants of afflicted areas.

The glass flake plaster can also make buildings more energy efficient by altering indoor temperatures during the process of changing humidity levels.