Understanding the Effect of Wildfire Smoke and Hvac Settings on Indoor Air Quality Using Networked Sensors

FIONA HOPEWELL, Tristalee Mangin, Colin Schermerhorn, Kerry Kelly, University of Utah

     Abstract Number: 295
     Working Group: Indoor Aerosols

Abstract
Poor indoor air quality (IAQ) is associated with numerous adverse human health effects. Yet, it has been less frequently studied than outdoor air quality. We have been operating a 21-node IAQ network since 2023, and our initial studies suggested that wildfire smoke infiltration occurs more frequently in buildings with certain types of HVAC systems, specifically those that have air-side economizers. This study focuses on the summer of 2024 (May 15 to October 31) when six significant wildfire smoke events, where the outdoor AQ was above 30 ug/m3, affected the University of Utah and each event ranged from 1 days to 7 days in length. It aims to further understand the impact of wildfire smoke on indoor PM2.5 and CO2 concentrations using the sensor network (17 indoor and four outdoor). The sensor locations are categorized into three building HVAC types: 1. variable air volume systems with a MERV 13 filter and an airside economizer, 2. dedicated outdoor air system with a MERV 13 filter, and 3. Window mini split air handling unit with MERV 8 filter. Our results showed that HVAC 1 had the highest indoor-to-outdoor PM2.5 correlation and hourly average PM2.5 concentrations compared to HVAC types 2 or 3. Additionally, we are working with the facilities management on a pilot program to evaluate the effectiveness of HVAC management strategies to mitigate PM2.5 infiltration during wildfire smoke events.

Conflict of interest: Dr. Kelly has a financial interest in Tellus Networked Sensor Solutions, Inc., which commercializes environmental monitors.

Program Topics: Indoor Air: Sensors Driving Indoor Air Optimization