At QleanAir, we receive a lot of enquiries from companies wondering how they can clean the indoor air to attract the staff to the workplace after the pandemic. As we have identified a growing need, we wanted to find out exactly how effective our air cleaners are in the fight against airborne viruses in indoor air. Therefore, we performed a joint study with Virus Research Center, Clinical Research Division at Sendai Medical Center, in Japan. The study was conducted using our mobile air cleaner QleanAir FS 30 with two different filters settings, HEPA 14 and EPA 11, on active influenza virus in a closed space of 25 m3. The results show clearly that the air cleaners significantly improve the air quality in very short time.