How often 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 home
For basic 1"–3" air filters, manufacturers usually instruct you to get new ones every 30–60 days. If you suffer from light to moderate allergies, you could upgrade the air filter or replace them even more often.
Or, if you're in a more country spot or less occupied house (like a vacation house) and there are not as many cars around, every year could be often enough.
Here are averages that might help you decide 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 home without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days