Wildfire Smoke: Effective Indoor Air Filtration Strategies
Wildfire smoke is currently affecting air quality across parts of the United States, leading to increased indoor pollution levels. The Environmental Protection Agency (EPA) recommends specific measures to mitigate the impact of smoke indoors, particularly through the use of high-efficiency air filtration systems.
According to the EPA, homes equipped with a MERV 13 HVAC filter can reduce indoor particulate matter (PM₂.₅) by approximately 80% when the system is run continuously. This level of filtration is particularly important during wildfire events when outdoor air quality significantly deteriorates.
In addition to HVAC systems, the EPA suggests the use of portable air cleaners (PACs). These devices can independently lower indoor PM₂.₅ levels by 50% to 80%, with an average reduction of around 65%. The combined use of a MERV 13 filter and a PAC can achieve an indoor PM₂.₅ reduction of about 80% during intense smoke events.
For those without access to high-efficiency HVAC systems, portable air cleaners offer a viable alternative. However, their effectiveness can vary based on the specific layout and conditions of a home. Research by the National Institute of Standards and Technology (NIST) indicates that in real-world settings, PACs can achieve a steady-state removal of particulates ranging from 45% to 70%, depending on their placement within a home.
The EPA also advises temporarily turning off mechanical ventilation systems during heavy smoke events to prevent further smoke entry, resuming normal ventilation once outdoor air quality improves.