How often you should replace your air filters could depend on the following:
- Air filter kind
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the residence
For basic 1"–3" air filters, manufacturers typically instruct 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 replace them even more frequently.
Or, if you reside a more country area or less occupied residence (like a vacation house) and there are fewer cars around, every year may be often enough.
Here are averages that may help you know how often you should get a new air filter at your residence:
- Vacation house 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