Indoor Organic Aerosol Formation Near Occupants in an Occupied Classroom Using Computational Fluid Dynamics Simulations

SUWHAN YEE, Donghyun Rim, Pennsylvania State University

     Abstract Number: 548
     Working Group: Indoor Aerosols

Abstract
Understanding the formation and transport of particles in an occupied space is essential to lower human exposure to particles. The objective of this study is to advance the understanding of the formation of secondary organic aerosols (SOA) in environments characterized by thermal conditions indoors. The core of this study involves integrating the volatility basis set (VBS) model with computational fluid dynamics (CFD) simulations. The CFD model simulated SOA formations due to the ozone reaction with terpene in a standard classroom. The model's accuracy was validated using empirical data from existing measurement studies and a traditional well-mixed model. The study results show that the concentrations of SOA near occupants are lower compared to the ambient air in the room, whereas the concentrations of semi-volatile compounds are significantly higher in proximity to occupants. [dR1] This trend is mainly attributed to high temperature and buoyancy-driven thermal plume developed in the proximity of the occupants. The study further revealed a notable variation in indoor particle concentration[dR2] [dR3] , up to about 30%, despite consistent air exchange rates and average room temperatures. This variation is primarily because of distinct local airflow patterns and temperature gradients associated with cooling or heating of the occupied space.