Photo: While many commercial HVAC systems come equipped with MERV-rated filters, these aren’t necessarily sufficient when wildfire smoke rolls in. | Photo Credit: Adobe Stock
By Shawn Gilstorf
As climate change intensifies, green building professionals face a new and growing threat: wildfire smoke. Once viewed as a regional issue, smoke from large-scale wildfires now drifts across continents, bringing with it a complex mix of particulate matter and chemical gases that compromise indoor air quality (IAQ), building performance, and occupant health—even in facilities designed to the highest sustainability standards.
According to the EPA, wildfire smoke now accounts for nearly half of all PM2.5 pollution in the western United States. That figure is expected to rise as fire seasons grow longer, hotter and more destructive.
Wildfire smoke is not just an outdoor air issue. It’s infiltrating some of the most advanced commercial buildings in the country—buildings with LEED certifications, tight envelopes and high-efficiency HVAC systems. The systems were designed for typical urban pollution loads, not the extreme particulate and gas-phase pollution seen now.
Rensa Filtration is working to close that gap by providing filtration solutions tailored to wildfire smoke, designed specifically for commercial and institutional environments that prioritize energy efficiency and sustainability.
What Makes Wildfire Smoke So Dangerous?
Wildfire smoke is a complex, evolving mixture. It contains:
- Fine particulate matter (PM2.5) – microscopic particles that can penetrate deep into the lungs and bloodstream.
- Volatile organic compounds (VOCs) – gases that off-gas from burning vegetation, construction materials and plastics.
- Nitrogen oxides (NOx) – pollutants that contribute to smog and respiratory distress.
These pollutants can linger in the air for days and travel thousands of miles. Buildings designed for tight envelopes and energy recovery can inadvertently trap these pollutants indoors, especially when outdoor air intakes are active during poor air-quality events.
Even high-performance buildings with advanced MERV-rated filters may not fully address the spectrum of wildfire smoke pollutants, particularly when it comes to VOCs and gases.
Why Standard HVAC Systems Aren’t Enough
Most commercial HVAC systems use filters rated MERV 8–13, which provide some protection against PM2.5, but struggle to handle the full load of wildfire smoke. Many don’t include any gas-phase filtration at all.
Even a well-sealed building with MERV 13 filters can be overwhelmed during a heavy smoke event, and the energy burden of pushing air through a clogged or underperforming filter can run counter to sustainability goals.
In response, facility managers should consider multi-layered filter systems that target both particulate and gas-phase pollutants while balancing energy efficiency and system longevity, including:
- High-efficiency particulate filters (HEPA or MERV 16) that trap the finest smoke particles
- Gas-phase filtration using activated carbon and advanced sorbents to remove VOCs and odors
- Custom filter housings that retrofit into existing HVAC systems without compromising airflow
Green Building Strategies for Wildfire Resilience
With wildfire smoke becoming a seasonal reality across North America, building owners and sustainability consultants are beginning to view air quality resilience as essential to green building design and operations.
Here are four recommended steps for any facility pursuing or maintaining a green building certification:
- Upgrade to Wildfire-Ready Filtration
Consider moving beyond MERV 13 to filters explicitly engineered for smoke, including options combining high particulate efficiency with gas-phase media for VOC and NOx removal. - Conduct an Envelope Tightness Audit
Even LEED-certified buildings can suffer from unintended infiltration. Sealing gaps, maintaining pressurization strategies and verifying ventilation rates can prevent contaminated outdoor air from entering unfiltered. - Install Indoor Air Quality Monitoring
Incorporating IAQ sensors into building automation systems (BAS) allows real-time response to outdoor air conditions. This includes dynamically adjusting outdoor air intake, system mode or filtration based on IAQ alerts. - Develop a Smoke-Response Protocol
Integrate smoke events into a facility’s emergency plan, including trigger thresholds for outdoor air shutdown, internal air recirculation and tenant communication.
A Climate-Adaptive Future for Green Buildings
One of the key concerns for green buildings is how to address air quality threats without increasing a facility’s energy footprint. This requires constantly balancing three priorities: filtration effectiveness, system compatibility and energy efficiency. With the right system design, one priority doesn’t have to be sacrificed for another. Rensa Filtration can serve as a resource to provide technical guidance for facility professionals seeking to protect IAQ in LEED, WELL and Fitwel-certified buildings.
Wildfire smoke has introduced a new level of complexity to sustainable design. It’s not enough to simply build tight envelopes and energy-efficient ventilation systems. Today’s green buildings must be climate-adaptive and capable of maintaining healthy air quality in a world with shifting environmental baselines.
Healthy buildings are the foundation of sustainable communities, and clean indoor air is a core part of that. Wildfire smoke is going to test what that really means in practice.
With integrated filtration, data-driven air monitoring, and thoughtful operational planning, facility professionals can ensure buildings remain safe havens—even when the air outside is anything but.
Shawn Gilstorf is president of D-Mark, a Rensa Filtration Company specializing in advanced molecular filtration solutions and manufacturing for critical facilities. With decades of experience in commercial air quality, Gilstorf helps clients navigate complex environmental challenges with tailored filtration strategies.