Static and dynamic airflow and contaminant transport in a full-scale elevator-lobby mockup

Abstract

Elevators facilitate people's movement in daily life. The confined space with high population density in elevators, however, assists the transmission of infectious diseases. To study disease transmission under various transit and boarding-period scenarios, this study used a full-scale elevator mockup with a connected lobby area. This investigation measured both static and dynamic distributions of air velocity/temperature and contaminant concentration. The static experiment involved the closed elevator cabin with mixed ventilation, while the dynamic measurements were conducted in the elevator with the door open to the adjacent lobby area when a passenger exited the elevator. The dynamic experiment showed that high-frequency instruments and better background airflow design could increase the data quality. The experimental data was then used to validate a computational fluid dynamics (CFD) model. This study compared the average and individual experimental data to minimize the uncertainties caused by the initial conditions and instrument limitations. The simulation results revealed that an in-transit elevator cabin is characterized by relatively uniform distributions of air temperature and contaminant concentration. The airflow in the dynamic case was greatly affected by the wake generated by passenger movement. This wake effect was short in duration, but it drew contaminants farther along the direction of movement.