Understanding the Fate and Composition of Indoor Particle Mix
CHETHANI ATHUKORALA, Suresh Dhaniyala,
Clarkson University Abstract Number: 390
Working Group: Indoor Aerosols
AbstractIndoor airborne particle population constitutes both human-generated and outdoor-originated particles. The concentrations of indoor particles depend on the ventilation rates, efficiency of any inline and in-room filters in place, and the impact of mechanisms such as deposition and re-suspension. During COVID, it became clear that indoor particles generated by humans could have an impact on human health. In the absence of an ability to separate particles by source, it was deemed necessary to reduce the concentrations of all indoor particles. To minimize energy use, however, it would be best to identify just the threat particles, i.e., those emitted from human activities, and act to reduce their concentrations. In this study, we combine theoretical modeling with experimental data to extract information about human generated particles from real-world classroom activities. Using a network of research-grade instruments and low-cost sensors, we obtained comprehensive particle concentration and size distribution data over 18 months with varying classroom usage patterns, environmental conditions, and ventilation settings. Our analysis shows that human particle emissions are small fraction of total aerosol but a major contributor to super-micron particle population. The human-generated particle concentrations determined from our real-world study are lower than that estimated from laboratory studies. In this presentation, we will present our approach to extract information about the human-generated particle population from indoor air measurements that are dominated by outdoor particles. We will also highlight the relation between operational changes of building ventilation system with the indoor air quality in the room.