Indoor aerosol sensing and resuspension dynamics

Exposure to indoor particulate matter (PM) is associated with adverse health effects. Controlling the indoor PM exposure relies on an accurate understanding of aerosol transport, as well as accurate real-time monitoring of PM concentration level in the indoor environment. Indoor aerosol transport is a cycle involving continuous repetitions of deposition and resuspension of particles from indoor surfaces. Occupants’ activities such as walking, and indoor environmental conditions such as relative humidity (RH), influence the resuspension rate of particles. The first objective of this dissertation was to investigate the effects of RH and turbulent air swirls on the resuspension rate of allergen carrier particles from indoor surfaces. This study shows that increasing RH can reduce the resuspension and spread of hydrophilic particles such as dust mites and that the presence of carpet significantly increased resuspension rates compared to linoleum flooring surfaces. This study also analyzes the efficacy of indoor PM sensing with current technologies. Effective PM removal strategies depend on continuous monitoring of indoor aerosols. Although PM monitoring in buildings has not been feasible due to high PM sensor cost, the recent advent of low-cost optical PM sensors has enabled real-time PM monitoring with high spatiotemporal resolution. Since biological particles such as dust mites, pollen, and pet dander are linked to respiratory and allergic symptoms among building occupants, PM sensors can be utilized to accurately measure bioaerosols. However, the performance of low-cost particle sensors in monitoring bioaerosols is under-investigated. Thus, the …