1. Upgrade and actually change your filter
A MERV 11 to 13 filter captures fine dust, pollen, and smoke particles that a cheap fiberglass filter passes straight through. Replace 1-inch filters every 60 to 90 days, monthly with pets. Confirm your system can handle the higher MERV before jumping to 13.
2. Control humidity
Keep indoor humidity between 30 and 50 percent. Above that, dust mites and mold thrive; below it, sinuses and wood floors suffer. Run bath and kitchen exhaust fans and address any moisture in crawl spaces.
3. Clean the ductwork and dryer vent
Ducts hold years of settled dust, dander, and construction debris that recirculate every cycle. Cleaning every 3 to 5 years removes that reservoir, and an annual dryer vent cleaning removes both a lint fire hazard and a source of humid, dusty air.
4. Handle wildfire smoke season
- Close windows and set HVAC to recirculate during smoke events
- Run a portable HEPA purifier in bedrooms
- Replace filters after heavy smoke, not on the usual schedule
- Schedule duct cleaning after prolonged smoke exposure
5. Reduce the sources
- Use exhaust ventilation when cooking, especially on gas
- Choose low-VOC paint, flooring, and cleaning products
- Keep entryway mats and take shoes off indoors
- Vacuum with a sealed HEPA vacuum weekly
- Never idle a car in an attached garage
6. Have the system inspected annually
A dirty evaporator coil, a leaking return, or an undersized filter slot will undo everything else. An annual HVAC inspection catches those, and sealing leaky returns stops attic and crawl-space air from being pulled into your living space.