Room Air Cleaner: Everything You Need to Know
When we talk about indoor air quality, VOC and formaldehyde pollution continue to play a decisive role. Since 1 January 2016, formaldehyde has been classified in the hazard class, and officially considered carcinogenic.
The wood-based panels carry the volatile organic compound into the interior, as they are still at least partly produced with formaldehyde-containing glues. No wood-based panels may be placed on the market that exceeds the limit value of 0.1 ppm.
However, this applies individually to each building component or piece of furniture. The addition of all emission sources thus allows the concentration in the room air to rise quickly above the limit value.
It is not surprising that all materials and building materials with a room air-cleaning effect define formaldehyde as their primary opponent.
The purpose of using these building materials is to noticeably reduce the concentration of pollutants in the room without having to remove or completely renovate the emitting components. For the neutralization of formaldehyde, the systems rely on different chemical or physical processes that are set in motion by adding certain substances to the material.
The following details tell how the cleaning effect works:
This additive has white pigment value and is mainly used in wall paints. Its functional principle is photocatalysis, in which, to put it simply, organic compounds are converted into carbon dioxide and water under UV radiation.
This process continues practically uninterruptedly, so there is no wear effect. The titanium dioxide is added to the wall paints in a particularly sophisticated formulation so that it does not also decompose the paint's binding agents. It also ensures that the additive works not only under UV light but also under the influence of visible light from interior lighting.
Keratin is a fibrous protein found mainly in human and animal horn substances such as hair, fingernails, toenails, claws, and hooves.
As an amino acid, keratin is a preferred reaction partner for formaldehyde; both easily combine to form very stable and harmless substances that remain permanently in the keratin carrier material. The most prominent example of a material containing keratin is sheep's wool. It is per se pollutant-decomposing, but this positive property can be further optimized by post-treating the wool.
Above all, the washing process and the pH value adjustment during washing ensure an enlarged, free and thus active fiber surface.
In addition to formaldehyde, sheep wool also reduces numerous other toxins such as nitrosamines, phenols, terpenes, nitrogen oxides and a few more. Sheep wool nonwovens are mainly used in the large-scale refurbishment of components contaminated with formaldehyde with a wool coat. This so-called contact effect is mandatory for some manufacturers.
Zeolite is a mineral rock of volcanic origin. The pores of the technically modified zeolite Y have small diameters of less than one-millionth of a millimeter, which creates large inner surfaces within the building material.
However, the pollutants are not only stored in these cavities because zeolite is a catalyst similar to titanium dioxide, which chemically converts the indoor poisons into harmless carbon dioxide and water. But unlike titanium dioxide, it requires neither UV nor other light for this purpose.
Accordingly, this process takes place without interruption and saturation is not achieved. Zeolite is already used as an additive in various materials and construction materials during production. The addition of zeolite does not affect the technical workability of the panels or plasters.
Clay and Lime
Just like sheep's wool, natural building materials such as clay and lime have a cleaning effect on the ambient air. The result is based on a combination of highest diffusion openness, sizeable inner surface, and high porosity.
The most significant effect comes from the substantial and simple moisture migration from the room air into the interior of the building component (paint, plaster or plate), in which a whole transportation amount of pollutant molecules happen.
The clay absorbs the crystal lattices of the clay minerals contained in the pollutants. The already mentioned addition of zeolites intensifies the cleansing effect of a lime plaster or lime paint in the red lime variant.