How frequently you should install new air filters may depend on the following:
- Air filter kind
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the residence
For basic 1"–3" air filters, manufacturers usually direct you to install new ones every 30–60 days. If you have from light to moderate allergies, you could get a better air filter or replace them even more often.
Or, if you live a more rural location or less occupied home (like a vacation house) and there are not as many cars around, yearly could be often enough.
Here are averages that may help you know how regularly you should replace 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