AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Size-resolved Particle Emissions from Seated Occupants
YILIN TIAN, Seema Bhangar, William Nazaroff, University of California, Berkeley
Abstract Number: 365 Working Group: Indoor Aerosols
Abstract Human occupancy is known as a source of indoor inhalable particles, mainly attributable to a combined process of shedding and resuspension. Previous studies have focused on occupant emissions associated with walking, whereas little is known about the emissions from seated occupants. This work investigates particle emissions from seated occupants obtained via observational measurements and chamber study conducted under controlled conditions. The observational measurements were made in a university classroom. Optical particle counters were applied to measure size- and time-resolved concentrations for 44 lecture periods. Size-resolved emission rates were estimated using a one-compartment mass-balance model applied for steady-state conditions. Geometric mean (GSD) of per-person emission rates were 3.0 × 10$^6 (2.0) particles/h per person for particles with optical diameters in the range 2-5 microns and 8.7 × 10$^5 (1.6) particles/h per person for particles larger than 5 microns. The number of occupants did not significantly influence per-person emission rates. The complementary chamber study will further investigate the emissions from the human envelope and from the floor while participants are seated, undertaking scripted activities. The results of this work are of potential use in indoor air quality models and can lead to a better understanding of human occupants as sources of airborne coarse particles.