A time-based analysis of the personalized exhaust system for airborne infection control in healthcare settings

In healthcare centers, healthcare workers would not know if patients are infected or not until the infected person is diagnosed and moved to an isolation room; therefore, the effectiveness of ventilation systems in removing the exhaled infectious air in the consultation room becomes important. To prevent the transmission of exhaled air, two types of personalized exhaust devices were explored: top-personalized exhaust and shoulder-personalized exhaust. Three different arrangements with 30 cases between 2 manikins were studied experimentally using tracer gas. The intake fraction was compared with and without the personalized exhaust at the end of three different exposure durations: 10, 20, and 30 min. The results show that after applying either top-personalized exhaust or shoulder-personalized exhaust, the intake fraction is significantly decreased. With the higher flow rate of 20 L/s of personalized exhaust, the intake fractions at 30 min are found to be even lower than the intake fractions at 10 min without personalized exhaust. This implies that despite a longer exposure time, if the exposure amount is reduced, the infection risk is observed to be lower.