Understanding the effect of outdoor pollution episodes and HVAC type on indoor air quality

Abstract

This study evaluated the impact of poor outdoor air quality on indoor air quality over 18 months using 21 low-cost PM_2.5 sensors (at 17 indoor and two outdoor locations) with a focus on inversion, dust, and wildfire smoke events. In addition to the impact of outdoor air quality on indoor air quality, this study evaluated how different heating, ventilation, and air conditioning (HVAC) systems affect the infiltration of outdoor PM_2.5 in commercial buildings. Wildfire smoke events had the largest impact on indoor air quality. Infiltration factors averaged over all locations for inversion, dust, and wildfire smoke events were 0.07, 0.10, and 0.37, respectively. Additionally, HVAC systems equipped with an air-side economizer showed higher PM_2.5 infiltration factors compared to other systems regardless of pollution event.