How frequently you should change 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 home
For basic 1"–3" air filters, manufacturers often instruct you to install new ones every 30–60 days. If you have from light to moderate allergies, you could upgrade the air filter or replace them even more often.
Or, if you live a more remote area or less occupied house (like a vacation house) and there are a reduced number of cars around, every year may be regular enough.
Here are averages that might help you know how frequently you should change the air filter at home:
- 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