Abstract
COVID-19 in the world in 2020 is typical microbial airborne infectious disease, which cause immeasurable human losses, even far more than PM₂.₅, formaldehyde, VOCs and other hazards. An aerosol is a mixture of air with solid or liquid particles dispersed in it. Microorganisms generally have a certain volume, the air cleaner can use conventional filtration technology to remove air microorganisms. For this reason, the annual domestic sales of air cleaners in Japan increase about 3 million units in this year. On the other hand, dust collection test methods for air cleaners are specified in JEM1467（ Japan）, GB/T18801（China） and AHAM AC-1（ US） respectively. As a test method for determining the removal performance of air cleaners against airborne viruses, there is JEM1467 Annex D “Evaluation test of air purifier removal performance against airborne viruses” by the Japan Electrical Manufacturers’ Association. However, in
actual tests, from the viewpoint of biohazard, bacteriophages such as MS2 and Phi-X174 are used instead of viruses. By the way, since the particle size of droplet nuclei in influenza virus and SARS-CoV-2 is said to be about 0.1μm, the authors used alternative particles with virus-equivalent diameter （for example, KCl, PAO, PSL, Tabaco smoke etc.） as the test particles. In this study, comparative experiment was conducted to determine the removal performance of an air cleaner using Escherichia coli bacteriophage and virus-equivalent diameter substitute particles as test particles.
