Simulation of UVC disinfection system in healthcare settings

Abstract

During the present Covid-19 pandemic, development of ultraviolet-C (UVC) disinfection systems has dramatically increased. Much research has been steered towards UVC disinfection as a "no-touch"decontamination method. Despite the increased use of UVC disinfection in healthcare settings, little data is available on UVC dosage and exposure time to achieve complete disinfection in typical healthcare settings. Hence, this study aims to explore a reliable method for UVC dose simulation and planning for surface disinfection in healthcare settings. An open-source software, DIALux evo 9.0 by DIAL GmbH, was used to simulate the coverage and intensity of a representative light source in 3-dimensional (3D) rooms. The light intensity (in the unit of Lux) was then converted to UVC intensity (in the unit of μW/cm2) using a conversion factor obtained from experimental setup. A typical clinical consultation rooms (including furniture, surfaces material and colours) with different configurations of UVC lamps layouts (in terms of number of lamps and arrangement such as parallel, series, vertically and horizontally) was simulated and UVC dose was calculated. Optimum configuration of UVC lamps installation was then determined based on the maximum coverage of UVC radiation in the room within the minimum exposure time. The simulation and UVC dose calculation would greatly help the users in achieving optimal UVC disinfection of the whole room/area. Further experiments are needed to validate the findings from this study before the method can be widely used.