How often you should replace your air filters could depend on the following:
- Air filter model
- Complete indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the residence
For basic 1"–3" air filters, manufacturers often tell you to replace them every 30–60 days. If you suffer from light to moderate allergies, you could get a better air filter or replace them even more frequently.
Or, if you're in a more remote area or less occupied residence (like a vacation residence) and there are fewer cars around, yearly might be often enough.
Here are averages that might help you decide how often you should change the air filter at home:
- Vacation home or single occupant and no pets or allergies: every 6–12 months
- Common suburban residence without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days