EXPLORING THE EFFICACY OF AIR FILTRATION ON RESPIRATORY PARTICLES IN CREATING A HEALTHY MICRO-ENVIRONMENT INDOORS

Abstract

Since the outbreak of the coronavirus disease 2019 (COVID-19), there have been many variants that have emerged; with the most recent being Omicron. COVID-19 is mainly transmitted in three modes: direct contact, respiratory droplets, and airborne transmission. With the higher transmissibility of the current Omicron variant, maintaining good indoor air quality (IAQ) becomes increasingly critical since humans spend 90% of their time indoors. Apart from the normal heating, ventilation, and air-conditioning (HVAC) system every building has, air purifiers have gained a new demand in an attempt to keep IAQ in a healthy range.

This paper aims to explore the efficacy of air filtration of respiratory particles through different filters selected – MERV 7, MERV 13, and HEPA. With HEPA filters being readily accessible on different online platforms, filtration effectiveness of filters procured from different sources was assessed. Apart from that, this paper compares the efficacy of air filtration at different fan speeds in creating a healthy micro-environment around building occupants. The experiments were done in the Field Experimental Chamber in the National University of Singapore by simulating sneeze and cough particles. Results collected showed that HEPA filters were able to filter respiratory particles better. Even though HEPA labelled filters can be easily procured online, not all HEPA filters are made the same and they should be carefully selected before placing it in an air filtration unit; especially when the ventilation within the space is not at its best.