Photocatalytic Inactivation Efficacy of SARS-CoV-2 in HVAC Systems
Freeman, Andrew J.; Anandan, Sudharshan; Blatchley, Ernest R. III; Horton, W. Travis; and Warsinger, David M., "Photocatalytic Inactivation Efficacy of SARS-CoV-2 in HVAC Systems" (2021). Discovery Undergraduate Interdisciplinary Research Internship. Paper 42.
Date of this Version
HVAC, COVID, SARS-CoV-2, virus, air purification, IAQ, indoor air quality
The coronavirus pandemic has emphasized a need for robust and reliable air purification systems in buildings; with that comes a need for a standardized testing methodology for air purification technologies in HVAC air circulation systems. One such method of air purification is photocatalytic oxidation (PCO), a mechanism in which a catalyst irradiated by light produces reactive molecules that degrade a wide range of pollutants, including the aerosols that carry COVID. This technology has primarily been used in aqueous applications, but there have recently been developments in air purification that have made it a promising contender to existing technologies. One of the main shortcomings in literature, however, is the lack of to-scale data, particularly in meeting realistic duct air speeds. The present work embodies three main goals. First, the literature validation of SARS-CoV-2 surrogates-- lab-safe MS2 and Phi6-- for aerosolized testing. Second, the establishment and validation of HVAC PCO test operating conditions. The primary conditions include room temperature and humidity, and duct velocities between 0.5 m/s and 2.5 m/s; measurements include pollutant degradation, pressure drop across the purification unit, irradiation of UV light, and ozone production. Third, the development of a robust test schematic procedure. A 2x2x50 foot duct in Herrick Laboratory will allow us to compare viral inactivation efficacy of standard filters, UV light, and PCO filters irradiated by UV light. Performance testing will provide insight into the efficacy of these systems in building-scale applications and allow us to make recommendations for future applications.