Wildfire smoke can travel hundreds or thousands of miles from active fires, bringing fine particulate matter (PM2.5), smoke odors and other airborne pollutants into commercial and industrial buildings.

For facility managers, maintaining indoor air quality during wildfire events requires more than simply replacing an HVAC filter. Filter efficiency, pressure drop, airflow, outdoor-air intake, building-envelope conditions and operating procedures all influence how much smoke enters and remains inside a facility.

A properly designed filtration strategy can help reduce the amount of fine particulate matter entering occupied spaces, manufacturing areas and sensitive processes. The appropriate filtration level depends on the HVAC system and the specific requirements of the facility.

Wildfire smoke presents both indoor-air-quality and operational challenges for commercial and industrial facilities. Fine particulate matter can enter buildings through outdoor-air intakes and uncontrolled air leakage, while smoke-related contaminants can place additional loads on HVAC systems and sensitive processes.

Air Quality Index (AQI) Levels

Monitor outdoor and indoor air-quality conditions to determine when enhanced wildfire smoke response procedures are appropriate.

PM2.5 and Wildfire Smoke

PM2.5 refers to particulate matter with an aerodynamic diameter of 2.5 micrometers or smaller. Because these particles are very small, they can remain suspended in air and penetrate deeper into the respiratory system than larger particles.

PM2.5 Particle Size Comparison

Fine particulate matter is an important component of wildfire smoke and is a key consideration when selecting HVAC filtration.

Smoke Particles, Odors and Gaseous Pollutants

Wildfire smoke is a complex mixture. Particle filters are designed primarily to capture airborne particulate matter, while activated carbon and other gas-phase filtration media can address certain odors and gaseous compounds. Facilities concerned with both particulate matter and smoke odors may therefore require a combination of filtration technologies.

Filter efficiency should always be evaluated together with airflow requirements and pressure drop. Installing a higher efficiency filter without confirming HVAC compatibility can negatively affect airflow or system performance. Facility managers should verify filter specifications with their HVAC professionals and equipment requirements before upgrading.

MERV, or Minimum Efficiency Reporting Value, provides a standard method for comparing HVAC filter performance across defined particle-size ranges. For wildfire smoke, facilities commonly consider MERV 13 and higher filtration because fine particles are an important component of smoke.

MERV 13

MERV 13 is often used as a practical filtration upgrade for commercial buildings and HVAC systems during periods of elevated particulate pollution. It should be selected only after confirming that the HVAC equipment can maintain required airflow with the filter installed.

MERV 14–15

MERV 14 and MERV 15 provide higher filtration efficiency than lower-MERV filters and can be appropriate for facilities requiring increased particulate control. The additional pressure drop and airflow requirements should be evaluated as part of the selection process.

HEPA Filtration

HEPA filters provide substantially higher particle filtration than conventional commercial HVAC filters and are commonly used in critical environments. They may be appropriate for pharmaceutical, healthcare, cleanroom, electronics and other controlled applications where higher levels of particle removal are required.

Different commercial and industrial HVAC systems require different filter configurations. The table below provides a practical starting point for evaluating common AccuraFil filter types. Final selection should be based on the HVAC equipment, airflow, available filter depth, pressure-drop limits and application requirements.

Important: MERV ratings should not be treated as a direct percentage of total wildfire-smoke removal. Actual filtration performance depends on particle size, filter design, airflow, installation, filter loading and HVAC operating conditions.

Preparing before smoke reaches the building is generally more effective than attempting to modify an HVAC system during an active smoke emergency. Facility managers can use the following framework as a starting point for their wildfire smoke response plan.

AQI can help facility managers determine when to activate pre-established wildfire smoke procedures. The following table is a general planning framework, not a substitute for facility safety procedures, occupational-health guidance or local emergency requirements.

Hospitals and Healthcare Facilities

Healthcare facilities require carefully designed HVAC systems because indoor air quality can affect patients, staff and critical clinical environments. Filter selection should follow the facility's HVAC design, applicable healthcare standards and required pressure-drop limitations.

Pharmaceutical and Cleanroom Facilities

Pharmaceutical and cleanroom environments often require substantially higher levels of particulate control than ordinary commercial spaces. HEPA filtration may be incorporated into appropriately designed systems where required by the process or applicable standards.

Food Processing

Food-processing facilities may need to consider both particulate contamination and smoke-related odors. Filtration requirements should be evaluated according to the specific process, product, HVAC system and applicable food-safety requirements.

Manufacturing Facilities

Manufacturing facilities can use higher-efficiency HVAC filtration to reduce the particulate load entering production and occupied areas. Filter selection should balance filtration efficiency with airflow and equipment requirements.

Data Centers and Electronics

Fine particulate matter can be an important consideration for facilities containing sensitive electronic equipment. Proper filtration and HVAC maintenance can help reduce the amount of airborne particulate matter entering conditioned spaces.

Commercial Office Buildings

Office buildings can review HVAC filtration, outdoor-air management and building-envelope conditions before wildfire smoke events. MERV 13 or higher filtration may be considered where compatible with the building's HVAC system.

Particle filtration and odor control are not the same thing. MERV and HEPA filters primarily address airborne particulate matter, while activated carbon and other gas-phase media can help address certain gaseous contaminants and odors.

Facilities experiencing both elevated particulate levels and persistent smoke odors may therefore benefit from a layered filtration strategy that combines particulate filtration with appropriate gas-phase filtration.

The amount and type of carbon media, contact time, airflow and contaminant concentration all influence gas-phase filtration performance. Facilities should select carbon filtration based on the specific application rather than relying on a generic odor removal percentage.

Explore AccuraFil's commercial and industrial air filtration products to find filter configurations for your HVAC system and application requirements.