Using ventilation and air cleaning to reduce the aerosol concentration in a laboratory room

This study aims to experimentally investigate the effectiveness of using air cleaners (ACs) and mechanical ventilation (MV) systems separately or in combination to reduce the aerosol particle concentration in indoor spaces. The measurements were performed in a laboratory room equipped with a MV system (using a fixed ventilation flow rate of 278 m3/h, corresponding to an air cleaning rate ACH = 2.5 h−1), two ACs (with a fixed CADR of 400 m3/h, corresponding to ACH = 3.7 h−1)), and 16 artificial aerosol generators (AGs) to represent an intentional multifold of human respiratory aerosol generation. Five possible realistic scenarios were reproduced during which the concentration of the aerosol particles was measured by means of five aerosol particle sizers (APSs). The results show that when two ACs and MV were used in combination, 90-99% of the aerosol particles was removed within 20 minutes, depending on aerosol particle size. In the scenario with one AC and MV, about 85-99% of the aerosol particles was removed within 25 minutes. Finally, when only two ACs or only the MV were used, about 75- 99% of the aerosol particles was removed within 30 minutes.