Demonstrating UVC LEDs inside Automobile HVAC Chambers for Clean Cabin Air and Airborne Transmission Risk Reduction 2022-01-0197

A global survey in December 2020 revealed a preference for surface and air disinfection in automobiles which may have been accelerated by the COVID-19 pandemic. The observed trend towards healthy cars may remain well after the current pandemic. Additionally, new safety features like CO₂ gas sensors, antimicrobial fabrics, and enhanced air purifiers have emerged. While automobile air purifiers trap contaminants using cartridge filters, they are not particularly efficient at removing viral particles and create large pressure drops, which must be compensated with larger fans, increasing power requirements and noise in the vehicle cabin. A HVAC system with integrated UVC-LEDs can inactivating viruses, bacteria, and mold. UVC LEDs are desirable because unlike mercury lamps, they do not pose electrical, glass, and chemical hazards. With the recent improvements in UVC LED lifetime and power, UVC LEDs are becoming a better alternative, as highlighted by recent upsurge of successful in air disinfection studies against SARS-CoV-2 and H1N1. In this paper, the KM model is applied to a vehicle, initial testing on 25 L/s shows half log reduction of E. coli, then a model of a disinfection chamber that could fit a vehicle HVAC is created, and finally a full size mock vehicle is disinfected using Phi6 as a surrogate. It’s estimated from this that 90% of SARS-CoV-2 could be eliminated in 5 minutes. This demonstrates the feasibility of UVC LEDs for aerosol disinfection in vehicles.