Miaomiao Hou, Jihun Kim, Jovan Pantelic, Dorit Aviv
A simulation technique is proposed as a tool to assess the efficacy of Ultraviolet Germicidal Irradiation (UVGI) devices as measures for controlling virus spread in occupied rooms’ retrofits. UVGI devices disinfect the air and surfaces in their range through intense UV-C radiation that causes DNA or RNA damage to microorganisms. This disinfection method is proved to be highly effective in reducing aerosol transmissions. For UVGI to be effective, maintaining a high level of UV-C fluence rate in the upper zone of the room is required for a sufficient time to achieve the necessary radiation dose for deactivating the microorganism. At the same time, it is necessary to ensure the safety of the lower zone with a low level of irradiation to avoid any potential damage to human eyes and skin in the room. To determine the proper spatial distribution of the UV irradiation, we created an integrated workflow with raytracing and CFD simulation so that the airflow patterns and virus concentration can be accounted for along with the radiation intensity. This paper presents how design variables can optimize the distribution for effective disinfection and what safety precautions must be taken to avoid overexposure of people to UV radiation when deploying these devices within existing buildings.
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