AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
The CHEER Study: It’s a Complicated Association between Home Infiltration Rates and Respiratory Health
SHELLY MILLER, Jamie Humphrey, Prateek Shrestha, John Adgate, Elizabeth Carlton, Elisabeth Root, University of Colorado Boulder
Abstract Number: 91 Working Group: The Air We Breathe: Indoor Aerosol Sources and Chemistry
Abstract In the Colorado Home Energy Efficiency and Respiratory Health (CHEER) study we evaluated the relationship between home air-tightness, infiltration rates and characteristics, and occupant respiratory health of low-income homes across the Front Range of Colorado. Respiratory questionnaires, lung function testing, household walkthrough inspection, and blower door testing were used. An additional study was conducted over two summers investigating the impact of wildfires on indoor air quality in our study homes.
In summary, we found that in the questionnaire study homes with lower annual average infiltration rates (AIR) reported fewer respiratory symptoms. Furthermore, we suggest based on our analyses that one reason we see this association is because traffic-related air pollution is infiltrating the homes and impacting respiratory health as reported by questionnaire. Most of our homes were fairly leaky and had their windows open quite a bit especially during nice weather.
Conversely in the spirometry study we found that high AIR may be beneficial for lunch health. These results are more in line with previous studies. Note that the CHEER study by design sampled from low income, urban populations who are disproportionately burdened by respiratory illness. The study population in this study was more limited since many of the “sickest” could not perform the spirometry test. Thus, the spirometry sample is a healthier population compared to the questionnaire sample and perhaps less susceptible to subtle changes in air quality.
Investigations into the impacts of energy efficiency retrofits designed to tighten the building structure revealed that although these efforts did have an impact on lowering the AIR, the most significant factor determining air exchange was building volume and age. Duct sealing turned out to be quite effective as a retrofit.
The wildfire study showed that indoor levels of PM2.5, CO and black carbon were significantly impacted by the smoke plume. Of note was the fact that almost all homes kept their windows open and did not have air conditioning.
In an additional analysis to understand neighborhood characteristics as a whole we found four distinct types of neighborhoods and that these typologies can impact respiratory health.
Outcomes of this study will provide guidance on air-tightness and energy efficiency upgrade techniques that reduces energy use in homes while still providing a healthy indoor environment.