Effective pathogens inactivation in air ducts through UVC light

Abstract

The inactivation of airborne pathogens inside closed spaces is a critical issue, raised overwhelmingly during the current SARS-CoV 2 pandemic. Ultraviolet germicidal irradiation is a well-established technique that can effectively inactivate pathogens. In domestic and industrial air conditioning systems, large amounts of air flux can be sanified using mercury vapour lamps and proper shape and coating of a section of the air ducts. This paper describes the design of the UVC filter for air treatment unit which is in the installation phase at the headquarter of Centro Servizi Multisettoriale e Tecnologico in Brescia, Italy. The filter increased efficiency relies on concept of optical cavity, thanks to its shape and sources positions. Optical simulations have been carried out using a ray-tracing program, which has permitted to vary the parameters in order to maximise the internal irradiance quickly and thus the performance.