How frequently you should install new 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 house
For basic 1"–3" air filters, manufacturers often instruct you to change them every 30–60 days. If you deal with from light to moderate allergies, you could install a better air filter or change them even more regularly.
Or, if you're in a more country spot or less occupied house (like a vacation residence) and there are a reduced number of cars around, every year might be frequent enough.
Here are averages that can help you figure out how frequently you should get a new air filter at your house:
- Vacation house 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