Experimental assessment of an air curtain-sealed personal protective equipment for medical care: Influence of breathing and thermal plume

Abstract

This paper presents the performance assessment of a novel air-sealed visor for medical care based on experiments. This Personal Protective Equipment (PPE) provides effective aerodynamic sealing of the breathing zone, thus reducing the risk of inhaling droplets and aerosols carrying a potential viral load. The air curtain supply system was designed after computational fluid dynamics exploratory simulations to determine suitable airflow conditions. The main parameters under study are the air curtain velocities and the fraction of contaminated air in the breathing zone. The impact of different airflow rates, human breathing, thermal plume and lateral barriers to reduce the risk of leakage, was investigated. For the designed airflow rate and considering the worst-case scenario with a contaminated environment, results indicate that this PPE can reduce the contaminated air in the breathing zone by 31% and 82%, without and with lateral physical barriers, respectively. Although the human body thermal plume has a high impact on the air curtain velocity profile, it just affects the device efficiency by 2%. The breathing process increases the air curtain velocities improving the PPE efficiency by 32%. This study shows the potential of using a visor with aerodynamic sealing as an infection control barrier for healthcare workers.