  Airborne transmission of SARS-CoV-2 via virus-laden aerosols in enclosed
spaces poses a significant concern. Elevators, commonly utilized enclosed
spaces in modern tall buildings, present a challenge as the impact of varying
heating, ventilation, and air conditioning (HVAC) systems on virus transmission
within these cabins remains unclear. In this study, we employ computational
modeling to examine aerosol transmission within an elevator cabin outfitted
with diverse HVAC systems. Using a transport equation, we model aerosol
concentration and assess infection risk distribution across passengers'
breathing zones. We calculate particle removal efficiency for each HVAC design
and introduce a suppression effect criterion to evaluate the effectiveness of
the HVAC systems. Our findings reveal that mixing ventilation, featuring both
inlet and outlet at the ceiling, proves most efficient in reducing particle
spread, achieving a maximum removal efficiency of 79.40% during the exposure
time. Conversely, the stratum ventilation model attains a mere removal
efficiency of 3.97%. These results underscore the importance of careful HVAC
system selection in mitigating the risk of SARS-CoV-2 transmission within
elevator cabins.
