Mold is not the only cause for problems with indoor air quality
Inorganic fibers can also cause poor air quality.
(Text about this in March in Finnish tabloid, "Ilta-Sanomat")
These fibers entering the indoor air, may be the result of the materials (mineral and glass wool) used in the ventilation ducts in 1980 and 90’s. Especially in public buildings, such fiber sources are a much more common problem than mold.
Lifa has equipment for cleaning and coating such ducts! Contact us and ask for more!