Briefly explained: This is how the unique filter system of the AiroDoctor works

The unique quadruple filter system of the AiroDoctor air purifier covers an unusually broad spectrum: the AiroDoctor adsorbs 99.9% of all germs, chemicals, pollutants and fine dust particles from the room air and decomposes and neutralises them. Each of the filter layers connected in series has its own special function. The "mesh size" of the filters decreases with each layer, and in addition to purely mechanical filtering, chemical reactions finally help in the cleaning process. Thus, harmful gases, viruses, bacteria and unpleasant odours can be decomposed and neutralised, without any harmful residues!

The coarsest filter, the so-called pre-filter, catches everything that is just visible to the naked eye: hair, dust particles, dirt particles and dandruff. This filter must be vacuumed out with a standard hoover and washed under water at intervals of several weeks. It needs to be replaced after half a year of use at the earliest.

Smaller, no longer visible particles are then taken over by the HEPA, the High Efficiency Particulate Air Filter. This HEPA filter removes particles with a diameter between 0.3µm and 2.5µm from the air, for example viruses and bacteria, pollen and mite excrement as well as mould spores and gases. The particles get caught in the densely interwoven glass fibre mats, whose surface is greatly increased by folding. HEPA are classically used in sensitive rooms such as laboratories, operating theatres and intensive care units. Since the HEPA reaches a saturation level sooner or later, depending on its use, it naturally has to be cleaned every two months and replaced once a year.

Finally, the activated carbon filter offers two different cleaning mechanisms: it, too, can filter out smaller particles purely mechanically. In addition, the carbon acts as a reducing agent via oxidation processes and absorbs harmful gases such as ozone or chlorine and converts them. The activated carbon filter is thus the place where unpleasant and harmful odours from cigarettes, excreta or waste are intercepted and decomposed. An activated carbon filter can absorb several times its weight in foreign particles, but it also consumes itself at the same time due to the oxidation processes. Therefore, the activated carbon filter must be cleaned and replaced at regular intervals - similar to the HEPA and depending on the usage.

The last link in the filter chain, on the other hand, hardly wears out: the innovative UV LED photocatalysis filter. Through a chemical reaction with titanium dioxide (TiO2) triggered by light, it completely decomposes harmful gases, bacteria and viruses, among other things. This includes individual unbound viruses such as influenza or SARS-CoV-2, which, with a diameter of a good 0.1µm, are only half the size of a fine dust particle.

Unique for an air purifier is the fact that the photocatalytic filter is not only coated with the nanoparticles, but consists of 250 grams of solid titanium dioxide. This makes it the only filter of its kind and, due to its large surface effect, it is particularly low-wearing and durable.