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 usually tell you to get 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 regularly.
Or, if you live a more rural area or less occupied residence (like a vacation home) and there are not as many cars around, yearly could be regular enough.
Here are averages that could help you figure out how often you should get a new air filter at your residence:
- Vacation residence 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