How regularly you should replace your air filters may depend on the following:
- Air filter model
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the residence
For basic 1"–3" air filters, manufacturers typically tell you to change them every 30–60 days. If you have from light to moderate allergies, you could install a better air filter or change them even more frequently.
Or, if you're in a more country spot or less occupied house (like a vacation house) and there are a reduced number of cars around, every year might be regular enough.
Here are averages that might help you decide how frequently you should get a new air filter at your residence:
- Vacation house or single occupant and no pets or allergies: every 6–12 months
- Common 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