Design and optical simulation of heating, ventilation, and air conditioning duct incorporating ultraviolet-C channels based on Bunimovich stadium

Abstract

A recent breakout of the COVID-19 pandemic inspired researchers to find ideal solutions for removing SARS-CoV-2 from indoor air. In-duct ultraviolet germicidal irradiation was employed in rooms with heating, ventilation, and air conditioning (HVAC) systems to stop the spread of COVID-19. The current investigation introduces Bunimovich stadium-inspired flow channels inside the square-shaped duct. The impact of the Bunimovich channel shape on light distribution is studied and compared with the traditional rectangular-shaped duct. The core of the Bunimovich channel is a square with δ and γ equal to 0.5. A semi-circle surrounds the square's left and right sides. The air velocity in the HVAC system with the Bunimovich channels varies from 10 m/s to 15 m/s, resulting in variation in aerosol particles’ residence period in front of the ultraviolet-C (UVC) source. The Bunimovich channel delivered better UVC irradiance uniformity than a rectangular duct. The uniformity ratio for the Bunimovich channel was 0.788 compared to 0.6949 for the rectangular duct. The UVC dose delivered by the source in the Bunimovich channel varies from 1.48 mJ/cm2 to 3.03 mJ/cm2. The delivered dose is higher than the required 1.2 mJ/cm2 dose for log-4 reduction (i.e. 99.99%).