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