How regularly you should replace your air filters might depend on the following:
- Air filter model
- Complete indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the house
For basic 1"–3" air filters, manufacturers often tell you to replace them every 30–60 days. If you have from light to moderate allergies, you could install a better air filter or replace them even more regularly.
Or, if you're in a more rural spot or less occupied home (like a vacation home) and there are not as many cars around, each year may be regular enough.
Here are averages that can help you decide how often 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