Homes and buildings have become tighter structures to improve energy efficiency. Concurrently, wildfires have become more frequent. This change can negatively affect indoor air quality and human health.
In the article, “Indoor Air Quality and Wildfire Smoke Impacts in the Pacific Northwest,” that appears in the February 2018 edition of Science and Technology for the Built Environment, W. Max Kirk, Ph.D., Associate Member ASHRAE, and others present data for measurements at two houses during periods with and without high levels of wildfire smoke outdoors.
Kirk, an associate professor of construction management at Washington State University, discusses the significance of the research.
1. What is the significance of this research? Why is it important to explore this topic now?
Our goal for this research is to increase the understanding of indoor air quality and how climate change will impact indoor air quality. In recent years more attention has focused on indoor air quality, and there is much to learn about its relationship with the built environment. We also know the world we live in is impacted by climate change. The larger question then becomes, “How does climate change affect indoor air quality in our built environment, more specifically, our existing housing stock?”
2. What lessons, facts, and/or guidance can an engineer working in the field take away from this research?
Our approach involves investigating the ventilation rates and indoor/outdoor air quality of selected houses to produce a database for assessing the effects of climate variability, including extreme weather events, on occupant behavior, energy consumption, and corresponding indoor air quality in homes under actual use. Currently, the average home age in the U.S. is around 40 years (built around 1980). Some methodologies predict how to improve infiltration rates and indoor air quality in future built homes, yet we also need to have an understanding of how a variety of homes will react to more volatile changes in weather.
3. Were there any surprises or unforeseen challenges for you when preparing this research?
The major challenge has been how many variables there are out there from one home to another. I was most surprised at how much an enclosed home self-filters—no matter how airtight. In this particular paper, the overall results show low penetration rates for PM2.5 and ozone, and elevated indoor VOC levels due to a variety of indoor sources.
4. Can these findings be applied to buildings that face other climate events such as hurricanes?
Our research has not been conducted on homes experiencing hurricanes. However, CONTAM, the multi-zone indoor air quality and ventilation analysis computer program used to analyze our findings, can predict how various changes in future climate, coupled with air quality projections, will affect indoor air quality.
Wildfire events are predicted to only get worse in the future, so capturing the indoor air quality of two very different homes under extremely smoky conditions and placing that data in CONTAM will aid us immensely in predicting the impact of future climate changes on indoor air quality.
5. How can this research further the industry's knowledge on climate resilience and adaptability?
That is a difficult question. Again, we are looking at existing homes and, by using CONTAM, predicting how the indoor air quality of a home will react to climate change, and consequently the impact on its occupants. It is our hope that this research will indicate how we can adapt homes to changes in climate, such as through building codes, constructability, materials and products used, design, in order to have a positive influence on the health and well-being of their occupants.