How often you should replace your air filters could depend on the following:
- Air filter model
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the house
For basic 1"–3" air filters, manufacturers usually tell you to replace them every 30–60 days. If you deal with from light to moderate allergies, you could install a better air filter or change them even more frequently.
Or, if you reside a more remote area or less occupied house (like a vacation home) and there are a reduced number of cars around, yearly may be frequent enough.
Here are averages that could help you figure out how frequently you should replace the air filter at your house:
- Vacation house 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