Are air purifiers a scam

Do mobile air purifiers reduce the risk of corona infection?

With the cooler days in autumn, life shifts more to the interior. This also increases concerns about infection with the corona virus in schools, offices or cafes. Looking for useful additions too regular ventilation and the AHA rules (Keep your distance, hygiene measures and everyday mask) you quickly come across mobile air purifiers.

Because mobile air purifiers can - similar to ventilation - also reduce virus-containing aerosols (very fine droplets in the air) in the room. But can their use really help to avoid classes, meetings or drinking coffee with a hat and scarf?

  1. According to the Robert Koch Institute, air purifiers cannot prevent transmission in close face-to-face contact (less than 1.5 m), even if they effectively reduce the number of viruses in the room air.
  2. In addition, you would have to set up a mobile air purifier in all rooms that are shared in your own home.
  3. Neither an air purifier nor ventilation helps against surfaces contaminated with droplets, but washing with water and all-purpose cleaner or detergent ..
  4. Even if guests come to visit, an air purifier can - for the reasons mentioned above - neither replace the AHA measures nor ventilation.

According to the Federal Environment Agency, the mobile air purifiers can only do one supportive measure to reduce aerosols in the room air. Mobile air purifiers do not make ventilation superfluous simply because they are not able to exchange exhaled carbon dioxide for oxygen and to dissipate the excess moisture in the room.

Do not blindly trust the manufacturer's advertising claims. Statements that refer to the filter do not automatically apply to the entire room air. In particular, advertising statements relating to virus protection should be confirmed by independent, reputable bodies under realistic conditions. These can be, for example, accredited laboratories, state institutions or possibly universities.

Corona aerosols: ventilation is the be-all and end-all

The ventilation rules must also be observed when using a mobile air purifier! Rooms in which several people are present should be ventilated frequently. In this way, the possible virus concentration in the room air can be reduced. If there is no built-in ventilation system, we recommend using classic ventilation wide open window for 5 minutes. For a quick exchange of air with as little heat loss as possible, a short one is required Cross ventilation with draft optimal. On the other hand, windows that are permanently or temporarily tilted are less effective.

It all depends on the air filter

Not all mobile air filters are equally suitable for retaining virus-containing particles from the air. Air purifier models that use so-called "High Efficiency Particulate Air" (HEPA) Filter of the Class H13 or H14 can filter viruses or the finest droplets laden with viruses.

Change the air filter regularly

Air filters must be replaced after a certain period of use. The cost of the filters can vary greatly depending on the model. Many air filter sets cost between 39 and 140 euros - Stiftung Warentest has tested some air filters.

Adjust the cleaning performance of the air filter individually

The amount of filtered air should be matched to the size and occupancy of the room. In addition, the air intake and exhaust direction must be positioned in such a way that the air cleaner can suck in a large proportion of the room air and does not contribute to additional turbulence and distribution of virus-laden air in the room.

Be careful with certain air filter techniques

Air purifiers that come with ozone work can pollute the room air with this irritant gas. There is also the risk that the gas will react with other chemical substances in the air, creating new ones harmful substances arise. The Federal Environment Agency therefore advises against such devices.

Some devices ionize the room air - but that alone cannot render the corona viruses harmless. Ozone can also be formed when air is ionized.

Other mobile air purifiers or air disinfectors work with them UV-C light, i.e. high-energy, ultraviolet radiation. In principle, this radiation is able to render viruses harmless. The manufacturer should be able to prove that the radiation duration and intensity in the device are actually sufficient to effectively deactivate viruses, even with the largest adjustable air flow. Air purifiers with UV-C radiation should only be used to protect skin and eyes if it is certain that they will not release any UV-C radiation.


Do UV-C lamps for the home help against the coronavirus?

Manufacturers of UV-C lamps advertise that UV-C lamps kill viruses. But consumer advice centers advise against using it at home. You'll find more about it here.

This content was created by the joint editorial team in cooperation with the consumer centers Rhineland-Palatinate and North Rhine-Westphalia for the network of consumer centers in Germany.