How frequently you should install new air filters can depend on the following:
- Air filter model
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the home
For basic 1"–3" air filters, manufacturers typically tell you to install new ones every 30–60 days. If you suffer from light to moderate allergies, you could install a better air filter or get new ones even more often.
Or, if you're in a more rural area or less occupied house (like a vacation house) and there are fewer cars around, every year might be often enough.
Here are averages that can help you figure out how often you should get a new air filter at home:
- Vacation residence 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