How frequently you should install new air filters could depend on the following:
- Air filter type
- 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 tell you to change them every 30–60 days. If you deal with from light to moderate allergies, you could get a better air filter or change them even more regularly.
Or, if you're in a more country area or less occupied home (like a vacation residence) and there are fewer cars around, yearly could be frequent enough.
Here are averages that might help you know how regularly you should change the air filter at your house:
- Vacation home or single occupant and no pets or allergies: every 6–12 months
- Common 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