Numerical comparison of dispersion of human exhaled droplets under different ventilation methods

Stratum ventilation has been proposed to accommodate elevated room temperatures recommended by several governments in East Asia for energy saving. One key issue in evaluating the performance of stratum ventilation is whether this air distribution method performs significantly different in person to person infectious diseases transmissions. Particle dispersion in a classroom under mixing ventilation, displacement ventilation and stratum ventilation respectively are investigated by numerical simulation. The drift-flux model based on an Eulerian-Eulerian approach is adopted to simulate the particle movement in a room. The results show that the flow patterns created by different ventilation methods have great influence on the particle fates. The particle concentrations for the breathing zone under stratum ventilation are significantly lower than that under mixing ventilation and/or that under displacement ventilation, which imply that the risk of pathogen inhalation under stratum ventilation is lower than that under mixing ventilation and/or displacement ventilation. © 2013 Inderscience Enterprises Ltd.