How often you should change your air filters can depend on the following:
- Air filter kind
- Complete indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the home
For basic 1"–3" air filters, manufacturers usually tell you to get new ones every 30–60 days. If you suffer from light to moderate allergies, you could install a better air filter or get new ones even more frequently.
Or, if you live a more remote location or less occupied house (like a vacation residence) and there are a reduced number of cars around, yearly might be regular enough.
Here are averages that might help you figure out how often you should replace the air filter at your house:
- Vacation residence or lone occupant and no pets or allergies: every 6–12 months
- Average suburban home without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days