Biological aerosol; heating, ventilation and air-conditioning (HVAC); computational fluid dynamics (CFD); ultraviolet germicidal irradiation (UVGI) simulation
Current project: Airborne Virus Transmission and Viability in an Environmental Chamber
In order to size-selectively determine the airborne virus viability and the sampling effectiveness of the eight-stage non-viable Andersen cascade impactor (ACI), six viruses are being tested in an environmental chamber. The size-selective airborne virus viability is quantified by dividing virus biological decay with its physical decay for each of the ACI stage samples. The virus biological decay is measured by culture-based titration, and its physical decay is calculated from fluorescence intensity. Each condition is tested in triplicate, and the results are expressed in geometric mean and standard error. Statistical analysis is used to identify significant factors and the interactions between them. Three groups of tests were designed to test virus aerosols for different time durations, under different thermal conditions with and without the ultraviolet germicidal irradiation (UVGI), or through the filtration processes by "heating, ventilation and air-conditioning" (HVAC) filters of different "minimum efficiency reporting value" (MERV) ratings. In addition to the airborne virus tests, numerical methods will be utilized to calculate the aerosol trajectories and to simulate the UVGI inactivation processes. At the completion of the project, it is expected that the size-selective viability of the variety of airborne viruses under the tested conditions will be determined, the physical and biological effectiveness of common HVAC filters of different MERV ratings on infectious virus aerosol removal will be compared, and a method of the UVGI inactivation simulation will be developed for the future design of the UVGI facilities either for air or for water treatment.