Can the infection risk in elevators be negligible? A comparative study of airborne infection probability in elevators and conference rooms

Abstract

People in crowded and poorly ventilated elevators are at risk of respiratory infection. However, due to the short duration of the elevator ride, the transmission of respiratory diseases in elevators does not get enough attention. To evaluate the infection risk, this study investigated the airborne transmission of respiratory diseases in the hospital elevator by comparison to the conference room. A validated computational fluid dynamics (CFD) model was adopted to simulate airflow, temperature and tracer gas dispersion in the elevator and conference room. We used Wells-Riley model to evaluate the infection probability of the susceptible persons. In addition, the influences of source patient posture and ventilation strategy on the transmission of tracer gas were analyzed. The results showed that the infection probability in the elevator with 5 min (average 2.70%) was higher than that in the conference room with 50 min (average 1.77%). The effects of source patient posture and ventilation strategy on the infection probability in the elevator were more significant than those in the conference room. Local air circulation could gather the tracer gas inside a confined space in the elevator and led to a high infection probability. The infection risk of respiratory diseases in the elevator was non-negligible.