How often you should replace your air filters can depend on the following:
- Air filter model
- Complete indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the home
For basic 1"–3" air filters, manufacturers typically direct 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 get new ones even more frequently.
Or, if you live a more rural spot or less occupied residence (like a vacation house) and there are a reduced number of cars around, annually may be often enough.
Here are averages that could help you figure out how frequently you should get a new air filter at your house:
- Vacation house or one occupant and no pets or allergies: every 6–12 months
- Ordinary 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