Published by Comfy Castle Heating and Air
License # AEC01319 / LIC00252624
Last updated 2026-10-02
3 minute read
During wildfire smoke, follow local emergency guidance and reduce smoke entering the home while keeping the home safely cool. Use suitable HVAC filtration and, where helpful, a correctly sized portable air cleaner. Ask how to manage outdoor-air intake for your actual equipment.
How can you prepare your HVAC system before smoke arrives?
Identify your HVAC equipment and whether it has a dedicated outdoor-air intake. Keep the owner manuals and ask a technician how the system should operate during smoke. Buy compatible replacement filters before an event and record the filter type and dimensions so another household member can replace them correctly.
Check official local alerts and outdoor-air-quality information. If authorities direct evacuation, follow those instructions. An HVAC system or air cleaner does not make a home safe from an approaching fire, and indoor filtration is not a substitute for an emergency plan.
How can you keep smoke out while staying safely cool?
EPA advises keeping windows and doors closed during smoke, using appropriate cooling, and managing fresh-air intakes with recirculation or the intake closed where supported. An HRV or ERV brings in outdoor air; do not assume its standard filter makes that air suitable during wildfire smoke. Get equipment-specific operating guidance in advance.
If the home cannot remain safely cool, seek an appropriate cleaner-air location rather than staying in an overheating house. Reassess ventilation when outdoor air quality improves. Different cooling systems handle outdoor air differently, so advice for central AC should not automatically be applied to an evaporative cooler or a portable AC.
How should you choose a filter for wildfire smoke?
EPA recommends a high-efficiency HVAC filter, such as MERV 13, or the highest rating the system can accommodate. Filter depth alone does not establish smoke-particle capture or airflow suitability. The filter must fit correctly, and the equipment must support it. Ask for a compatibility assessment before changing the filtration setup.
For a system with suitable filtration, EPA advises running the fan more often during poor air quality. Confirm the appropriate setting for your equipment. Inspect filters frequently during heavy smoke and replace loaded filters as needed; do not rely on whether light shines through as a universal test.
When can a cleaner-air room help?
A portable air cleaner can supplement HVAC filtration in a room where people spend time. Select it for the room size and documented clean-air delivery rate, and avoid ozone-producing equipment. Whole-home and room filtration have different roles; neither should be described as automatically better in every situation.
What should a smoke-season plan cover for your home?
List the rooms you use most, the HVAC and ventilation equipment, existing filters, and any cooling limitations. Ask what can be changed through normal controls and what needs professional work. Comfy Castle’s air-quality service information is a starting point for assessing compatible filtration, while current emergency and public-health guidance remains the reference during an event.
Frequently Asked Questions
- Can I run central AC during smoke?
- Often, but first understand whether the system brings in outdoor air and how that intake is controlled. Follow equipment-specific guidance and keep the home safely cool.
- Does a thicker filter always capture more smoke?
- No. MERV rating, fit, airflow compatibility, and condition matter. Do not choose or reject a filter based only on its thickness.
- Can a portable air cleaner help?
- Yes, a suitable unit can clean air in its intended room and supplement HVAC filtration. Size it to the room and use its documented performance information.
- Should I leave an HRV or ERV running normally?
- Do not assume normal ventilation settings are appropriate during smoke. Ask how to manage its outdoor-air intake and filtration, and follow current local guidance.
Sources and further reading
This guide provides general homeowner information. Equipment instructions and an assessment of your home determine the work required. For help in the North and South Denver Metro Area, contact Comfy Castle Heating and Air.