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 often direct you to get new ones every 30–60 days. If you deal with from light to moderate allergies, you could get a better air filter or replace them even more frequently.
Or, if you live a more rural area or less occupied home (like a vacation house) and there are a reduced number of cars around, every year could be regular enough.
Here are averages that might help you figure out how often you should replace the air filter at your residence:
- Vacation residence or one occupant and no pets or allergies: every 6–12 months
- Ordinary 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