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 six 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 conversation delves into the cautious use of personal protective equipment (PPE) during wildfire events. Nilsson emphasises the need for caution when relying on masks, stating that while masks – especially N95 respirators – can offer some protection, they may not be sufficient for heavy labour or prolonged outdoor activities during high concentrations of wildfire smoke. Schmidt adds that individuals with higher susceptibility, such as pregnant individuals or those with respiratory conditions, should prioritise wearing well-fitted N95 masks rather than surgical masks.
Bourque shifts the discussion to the duration of protection measures and testing for small particles. Nilsson acknowledges the guideline’s focus on initiating measures at the beginning of a smoke event and the potential need for ongoing actions until seasonal variations indicate a reduction in smoke. He notes that the guideline may not explicitly address when to discontinue measures and suggests that the adoption of protective measures may become a new norm in areas prone to recurring wildfires.
Nilsson provides insight into the structure of ASHRAE guideline 44P, outlining that it begins with an introduction explaining the rationale behind its development, touching on the increasing frequency and impact of wildfires. The guideline includes historical data, health relevance and concentration timeframes to provide context for readers. The middle section focuses on new designs and retrofitting existing buildings, offering approaches to calculate loading factors on filters. The largest section, with a distinct voice, is directed at operators dealing with real-time responses during events. It emphasises planning ahead, avoiding reactive measures, and learning from past experiences. The guideline aims to collect and disseminate best practices, encouraging continuous improvement in dealing with wildfire smoke challenges.
Continued in part seven…
Source
Live webcast on ASHRAE website