Simulation of UVC Disinfection System for Public Facilities

One of the key transport mechanisms that has led the current Covid-19 pandemic outbreak to grow so quickly is airborne transmission. Diseases that are transmitted in this route is called airborne-transmitted diseases. People can catch such diseases by having a direct or indirect contact with the infectious droplets. Airborne transmission is worse in confined areas as compared to open areas and can become a hot spot for transmission. Due to this fact, different methods have been implemented to combat the transmission, in which one of them is by implementing Ultraviolet C (UVC) disinfection system where indoor areas has become a top priority for disinfection. However, up till now, there is no guideline on how to perform this efficiently to cover all the areas. Hence, this project will look into the use of simulation to optimise the use of UVC disinfection system, focusing on public facilities such as lifts, public toilets, restaurants, banks, and government offices. According to International Ultraviolet Association guideline, an amount of 40 mJ/cm2 doses is the recommended requirement to inactivate microorganism. When a targeted area is undergoing UVC disinfection process,the light intensity emitted by the UVC source will irradiate the targeted area to inactivate the microorganism. However, the disinfection effectiveness can be affected by irradiate distances and angles and exposure time. Therefore, this project will also be investigating the correlation between UVC light intensity and dose, and the effect of angles and distances on UVC light intensity and dose. For this project, the conversion factor of light intensity will be important because the light intensity output in the software is in lux unit where the light intensity output in the meter is in µW/cm2. The conversion factor will be obtained using previous recorded data. The conversion factor will then be applied in the simulation software to obtain an optimum configuration of UVC disinfection system to achieve the amount of 40 mJ/cm2 doses in various public facilities. The output of this research can be used to provide a guideline for future installation of such disinfection system in various settings.