A used disposable air filter is full of trapped dust and allergens, so it should be replaced and thrown away, not cleaned and reused. The exception is a washable or reusable filter, which is made to be rinsed and used again. Knowing which kind you have tells you exactly what to do.
This goes for both home HVAC filters and car engine or cabin filters. Here is how to handle each.
Disposable or Reusable?
- Disposable filters have a cardboard frame and pleated paper or fiberglass media. They are one-time use. Do not try to wash them, since that wrecks the media and lets dust through.
- Reusable (washable) filters usually have a metal or plastic frame and say “washable” or “permanent” on them. These are made to be cleaned and reused for years.
How to Clean a Reusable Filter
If yours is washable, vacuum off the loose dust, then rinse it with water (and mild soap if greasy) from the clean side out. Let it dry completely before putting it back, since a damp filter grows mold. A car’s reusable performance filter follows the same idea, with a special cleaning kit.
How to Dispose of a Disposable Filter
Used disposable filters are not recyclable in most areas, because the dirty mixed materials cannot be processed. Slide the old filter into a trash bag (to keep the dust contained) and put it in the regular trash. If you want to trim waste, you can tear off and recycle a clean cardboard frame, but the filter media itself is trash.
How Often to Replace
Most home HVAC filters last 1 to 3 months, sooner with pets or allergies. A car engine air filter is usually replaced around every 15,000 to 30,000 miles, and the cabin filter on a similar schedule. A clogged filter strains the system and wastes energy, so do not stretch it too far. For car filters, see our old car parts guide, and the declutter and recycle guide covers other household items.
Frequently Asked Questions
Can you reuse an air filter?
Only if it is a washable or permanent filter. Disposable pleated or fiberglass filters are one-time use and should be replaced, not cleaned.
Can you recycle air filters?
Used disposable filters are generally not recyclable because of the trapped dust and mixed materials. You can recycle a clean cardboard frame, but the media is trash.
How do you dispose of an old air filter?
Bag it to contain the dust and put it in the regular trash. Reusable filters should be cleaned and put back instead of tossed.
How often should you change an air filter?
Home HVAC filters every 1 to 3 months, sooner with pets. Car engine filters roughly every 15,000 to 30,000 miles, with cabin filters on a similar schedule.