ROLE OF CEILING FANS AND DESK FANS IN MITIGATING AIRBORNE TRANSMISSION INDOORS

Abstract

This research study focuses on the mitigation effects of ventilation devices, mainly ceiling and desk fans. Different ventilation strategies generate differing air patterns in an indoor environment and therefore understanding the concentration amount of inhaled aerosols by an exposed person is central in reducing the risk of contact-free airborne transmission. Ventilation air patterns are studied as they play a key role in preventing the spread of infectious diseases through the air. A tracer gas experiment using Sulfur Hexafluoride (SF6) was conducted with the use of a manikin face that act as the recipient under differing ventilation scenarios (i.e. ceiling fan and desk fan) to determine if the ventilation devices tested were effective in reducing infectious pathogens in an enclosed environment. The concentration of inhaled aerosols is used to calculate the infection risk. The SF6 concentration was measured at 3 specific locations (i.e. at the breathing zone, in the middle of the source and breathing zone as well as 0.1 metre height near the breathing zone). The effectiveness of these ventilation devices was statistically analysed through the use of t-tests. The results showed that the airflow patterns of the devices resulted in varying concentration levels of SF6, with the desk fan demonstrating the highest levels of concentration at the breathing zone compared to the other 2 scenarios.