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