How frequently you should change 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 home
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 install a better air filter or replace them even more frequently.
Or, if you reside a more rural location or less occupied home (like a vacation house) and there are not as many cars around, annually might be often enough.
Here are averages that may help you decide how frequently you should replace the air filter at your house:
- Vacation residence 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