Pre-filtration is essential to protect the catalyst from physical contamination by dusts, fibres or aerosols (e.g. paint overspray). These mechanical filter stages prevent particles from settling on the active surface and clogging the pores (fouling). In the metalworking industry or in woodworking plants, multi-stage filter systems are often used. Inadequate pre-filtration leads to an increase in exhaust back pressure and reduced cleaning performance, which can drastically shorten the service life of the catalyst. Expert concepts such as those of Pure Air therefore always integrate a filtration unit tailored to the process in order to ensure the longevity of the entire system.