Investigation of combined ventilation systems for infection risk mitigation during dynamic elevator rides

The COVID-19 pandemic has underscored the importance of indoor air quality in mitigating airborne disease transmission, particularly in confined spaces such as elevators. Elevators, characterized by limited ventilation and high occupant density, present unique challenges for infection control, especially in urban areas with increasing reliance on vertical transportation. Existing elevator design standards provide general guidelines but lack specificity in addressing ventilation performance, particularly under dynamic airflow conditions influenced by passenger movement. This study investigates the performance of combined ventilation systems in elevator-lobby environments under dynamic conditions using Computational Fluid Dynamics (CFD) simulations validated by experimental data. Key findings indicate that the confined design of elevators presents the highest infection risk to passengers, with passenger movement playing a secondary role. Maintaining social distancing is shown to significantly reduce infection risks. Additionally, both displacement ventilation and induction-displacement ventilation systems in elevators and adjacent lobbies substantially enhance contaminant removal efficiency, reducing particle concentrations in passenger breathing zones. Induction-displacement ventilation systems exhibit superior performance in minimizing localized contaminant concentrations, even in the absence of filtration measures. However, improper system configuration can lead to increased background concentrations in areas distant from the source. The results emphasize the necessity of developing comprehensive ventilation strategies for elevator environments that account for passenger movement and other influencing factors to optimize air quality, contributing to healthier built environments.