Current study confirms: Air purifiers effectively protect against indirect infection in enclosed spaces

99.982 percent effective: The University of Stuttgart tested the air purifier AmbiCube with real viruses.

These air purifiers are ready for delivery to improve the air quality in shops, authorities, schools, and offices. Companies that have suffered significant revenue losses during the pandemic can have up to 90 percent of the purchase price of an AmbiCube reimbursed through the Bridging Assistance II or III programs.

Current study from the University of Stuttgart confirms: Room air purifiers with so-called HEPA H14 filters effectively protect against viruses.

Scientists at the University of Stuttgart confirm the high effectiveness of air purifiers with so-called HEPA H14 filters against viruses. Studies with the AmbiCube from Keller Lufttechnik showed that the device filters out 99.982 percent of pathogens from the air.

Lockdowns and no end in sight: More contagious COVID-19 variants currently require even greater caution in social and work interactions than in the past. At the same time, contact restrictions and the closures of institutions and shops are causing increasingly serious social, health, and economic side effects. It is therefore all the more important to utilize available options to make group gatherings in enclosed spaces safer. The air purification specialist Keller Lufttechnik in Kirchheim unter Teck developed a mobile air cleaning device that removes viruses very effectively from indoor air. This is confirmed by a recent study at the University of Stuttgart. Dr. Daniel Dobslaw, head of the exhaust air cleaning division at the Institute for Settlement Water Management, Water Quality, and Waste Management, tested the Keller Lufttechnik AmbiCube air purifier with real pathogens. The positive result: the device filters 99.982 percent of viruses from the indoor air.

New: Test with real viruses

The high efficiency of the AmbiCube is thanks to a so-called HEPA H14 filter. Such airborne particle filters have been certified for a long time and are used, for example, in hospitals. They reliably filter tiny particles from the air – in addition to viruses, these include bacteria, pollen, spores, and fine dust. Scientists have previously demonstrated their effectiveness by producing tiny particles of different sizes with silicone oils and testing the filters with them. Dr. Dobslaw wanted to be more precise. Oil reacts differently than a virus, he says, so he now used real pathogens. “For our experiments, we used approximately harmless Phi6 bacteriophages for humans. These are viruses that exclusively infect bacteria.” The result is convincing: “We were able to show that the AmbiCube works very well. An efficiency of 99.982 percent is significantly higher than what other filters or methods offer,” he explains.

Where are air purifiers used?

Air purifiers are especially recommended in all indoor spaces used by multiple people: these can include offices and meeting rooms, medical practices and nursing homes, day-care centers and schools, hair salons, shops, gyms, canteens, or restaurants. “Powerful air purifiers make such places significantly safer because they substantially reduce the indirect risk of infection through virus-carrying liquid particles, so-called aerosols. These particles can remain in the room air for hours and are responsible for about 45 percent of infections, according to current knowledge,” says Ulrich Stolz, head of technology at Keller Lufttechnik. “However, direct infection through coughing (droplet infection) or contact with a virus-contaminated object (fomite infection) is still possible in rooms with filtered air. Therefore, we should continue to follow all known protective and hygienic measures,” the expert explains.

Long-term investment pays off

Lars Walter from Keller Lufttechnik reports that many customers are considering whether investing in an air purifier is worthwhile in the long run. “The answer is clear: yes,” he says. “Because the AmbiCube not only filters out COVID-19 viruses. It also reduces the risk of catching a cold or flu in the room. Allergy sufferers can breathe a sigh of relief because it removes pollen from the air. It also minimizes the health-damaging fine dust levels, which are very high in many indoor spaces,” he explains. A mobile air purifier is therefore a long-term investment in the health of everyone using the respective rooms.

Government funding

For companies that have suffered significant revenue losses during the pandemic, the government provides so-called bridging assistance. This includes support for purchasing mobile air purifiers. Entrepreneurs can have up to 90 percent of the purchase price of an AmbiCube reimbursed through Bridging Assistance II or III. This makes acquiring such devices affordable for many businesses and allows them to meaningfully expand their hygiene concepts.