What does filter content mean



HEPA filter (High E.fficiency-Particulate A.irfilter) are particulate filters that serve to remove over 99.9 percent of all dust particles larger than 0.1-0.3 micrometers (µm) such as viruses, respirable dusts, mite eggs and excretions, pollen, smoke particles, asbestos, bacteria, various toxic dusts and filter aerosols from the air. They are used, among other things, in the medical field (see DIN 1946), i.e. in operating rooms, intensive care units and laboratories as well as in clean rooms and in nuclear technology.

The so-called ULPA filters, which are also used in clean rooms with the highest requirements (ISO class 5 and better), are even more efficient. ULPA filters work with an efficiency of at least 99.999 percent compared to particles with a grain size of 0.1–0.3 µm.

The European standard for classification is EN 1822 with filter classes H10 – H14 (HEPA) and U15 – U17 (ULPA). According to the known filter effects, particles around 0.1 to 0.3 micrometers are the hardest to separate (MPPS = most penetrating particle size) - therefore, HEPA and ULPA filters are classified based on their effectiveness against these grain sizes using DEHS (= Di-2-Ethylhexyl-Sebacat) test aerosol.

Marketing term in household appliances

In household vacuum cleaners, fabric filters are used under the designation "HEPA filters", which are intended to hold back particles in addition to the dust bag. As a rule, a combination with an (activated) carbon filter is used to make these devices "Suitable for allergy sufferers" to advertise. These vacuum cleaner filter cartridges do not meet the definition of HEPA filters. Activated charcoal cartridges are also not suitable for achieving a permanent cleaning effect, since the filter volume is too small and the change intervals are too long.

Category: Filters