How regularly you should replace your air filters could depend on the following:
- Air filter model
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the home
For basic 1"–3" air filters, manufacturers often tell you to change them every 30–60 days. If you have from light to moderate allergies, you could install a better air filter or get new ones even more often.
Or, if you reside a more rural area or less occupied residence (like a vacation house) and there are a reduced number of cars around, annually could be often enough.
Here are averages that might 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 residence without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days