Air Filter Technologies Receive Renewed Attention During Covid-19 Pandemic

SARS-CoV-2: Air Purifiers Remove 90 Percent of Aerosols

According to a recent study conducted by the Goethe University in Frankfurt, the use of four commercially available air purifiers in a school classroom helped reduce the concentration of aerosols by 90 percent in half an hour. Professor Joachim Curtius, who conducted the week-long study with a class of 27 students, believes that, based on the findings, there are no reasons why air purifiers should not be used in the classroom to reduce the airborne transmission risk of SARS-CoV-2.

"On the basis of our measurement data, we've calculated a model that allows the following estimate:

An air purifier lowers the amount of aerosols to such a considerable degree that the risk of being infected by a highly contagious person, a superspreader, is greatly reduced.

That's why we're recommending that schools use HEPA air purifiers this winter with a sufficiently high air flow rate."

However, the Federal Environment Agency has advised caution – noting that the elimination of SARS-CoV-2 has not yet been clearly proven – and is generally critical of the use of mobile air purification equipment, considering it justified only in exceptional cases as an additional measure.

HEPA filters – up to 99.995 percent efficiency rate

The Goethe University findings show that air filters and purifiers equipped with HEPA (high efficiency particulate air) filters could provide additional protection against the Covid-19 virus by reducing the airborne transmission risk for SARS-CoV-2.  HEPA filters with the EPA (efficient particulate air) and HEPA designations are used to filter the smallest particles from the air. Filter classifications are assigned according to their respective capacity to filter out the most difficult to detect particle size, PM1, which also includes viruses. Only air purifiers equipped with H14-HEPA high performance filters can filter out even small viral aerosols (0.1 - 0.2 µm) from room air at a 99.995% efficiency rate. This means that H14 filters are used specifically in those areas where infection protection plays an important role. Medical use HEPA filtration systems also make use of ultraviolet-C (UVC) lights and panels with anti-microbial coating to kill off live bacteria and viruses caught in the filter media. There is still some debate as to how reliable these technologies are in practice, with sceptics arguing that the UVC lamp exposure time in air purifiers is too brief to effectively eliminate the virus.

German states funding air purifiers for schools

While it remains debatable how much protection air filters can provide in confined private spaces, their beneficial effect in protecting from airborne infectious diseases in public buildings and spaces – where ventilation is scarce or impossible – is widely recognized.

The federal states of Bavaria, North Rhine-Westphalia, Hesse, Rhineland-Palatinate, and Berlin are all seeking to promote the purchase and use of mobile air purifiers in schools. Bavaria, North Rhine-Westphalia and Rhineland-Palatinate are each providing EUR 50 million, with Hesse and Berlin setting aside EUR 10 million and EUR 4.5 million respectively to procure the necessary equipment.

Professor Christian Kähler, leader of the Institute of Fluid Mechanics and Aerodynamics at the University of the German Armed Forces in Munich, believes that devices that filter aerosol particles – and ergo viruses – from the air are an effective protection against the coronavirus when deployed in tandem with additional ventilation to replace the used air with fresh air.

Germany – Europe’s biggest air filter market

In 2018, more than 600,000 air purification units were sold in Germany. The domestic market for air purifiers and air filters is the largest within the European Union, recording growth of almost 40 percent in 2018 alone. Central to this growth has been continued growth in the German economy and heightened public awareness of residential air quality among the overall population. Although no reliable data for 2020 is available, market demand for the year and beyond is certain to be significant. The air purifiers used in the Goethe University study cost around EUR 150 each and EUR 260 when purchased individually. Although a survey of the participating students showed that noise was not perceived as disturbing (unless set to the highest level), it might also be surmised that demand for “quieter” devices – particularly in classroom contexts – will similarly grow. This, allied to changing consumer behavior and the ongoing Covid-19 crisis, means that significant opportunities will exist for air filter and purification technology providers for some time to come – both in Germany and beyond.
 

Companies interested in expanding to Germany and being part of Europe’s leading air purification market can contact the Germany Trade & Invest team.