Regular replacement of the filters, especially the HEPA filters, is essential for air purifiers to ensure their function and effectiveness. Saturated filters are no longer able to filter pollutants completely out of the air. It can even happen that the particles already bound in the filter are then released again and distributed in the room. In the past, HEPA13 filters with an already high separation rate of >99.95% (ioxy-HEPA13 filter: 99.97%) were mostly used in air cleaners. Due to the Covid 19 pandemic, the HEPA14 performance class became the preferred filter type within a very short period of time, as it guarantees an even higher filter effect (ioxy-HEPA14 filter: 99.996% with a particle size of 0.26 µm). For existing ioxy units already in use, the changeover to HEPA14 filters is unproblematic, as they are identical in construction to the ones previously used.