A public ASHRAE Journal podcast hosted a panel discussion where experts discuss the critical topic of protecting building occupants from smoke during wildfire and prescribed burn events. This is part five of a seven-part series.
Part five of seven. Image supplied by Matthew LeJune/Unsplash
The panel consists of:
- Daniel Bourque, host and professional engineer from Halifax, Canada
- Greg Nilsson, technical officer at the National Research Council of Canada. He actively researches technologies enhancing indoor air quality, with a specific focus on wildfire smoke since 2017
- Rebecca Schmidt, a professor and molecular epidemiologist at the University of California. She studies the health effects of various exposures during pregnancy, including wildfire smoke and air quality issues
The discussion resumes with a clarification from Nilsson that while certain types of smoke may contain more harmful particles or contaminants than others, the key takeaway is that there is no healthy smoke. Regardless of the source, inhaling smoke is inherently harmful.
Bourque poses a question to Schmidt regarding the relevance of smelling smoke as an indicator of air quality. Schmidt explains that while the presence of the smell can indicate the need for protection, the absence of the smell doesn’t guarantee clean air. She highlights the limitations of relying on the sense of smell and emphasises the value of using sensors and websites that assess multiple factors to provide a more comprehensive view of air quality.
Nilsson adds that websites monitoring air quality consider more than just detectable odours, providing a more accurate representation of the air quality, especially in larger cities.
Bourque shifts the focus to personal filtration, drawing parallels with the use of masks during the early days of the Covid-19 pandemic. He enquires about the effectiveness of masks, particularly in the context of wildfires. Nilsson explains that masks, including surgical masks and N95 respirators, are made from materials tested against particles of similar size to those found in wildfire smoke. However, he notes that the fit of the mask is crucial to its effectiveness, highlighting potential bypass issues if not properly fitted.
Nilsson connects this concept to HVAC systems, emphasising that a high MERV-rated filter is effective in removing particles but requires proper fitting within the system to prevent bypass. He cautions against relying solely on masks – especially in buildings – and acknowledges their limited effectiveness in poorly fitted or uncomfortable scenarios.
Continued in part six…
Source
Live webcast on ASHRAE website
