How often you should replace your air filters can depend on the following:
- Air filter type
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the home
For basic 1"–3" air filters, manufacturers typically direct you to change them every 30–60 days. If you suffer from light to moderate allergies, you could install a better air filter or replace them even more often.
Or, if you reside a more rural area or less occupied home (like a vacation home) and there are fewer cars around, annually could be often enough.
Here are averages that can help you figure out how often you should change the air filter at home:
- Vacation home or one occupant and no pets or allergies: every 6–12 months
- Ordinary suburban house without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days