How often you should replace your air filters could 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 often tell you to get 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 live a more rural spot or less occupied house (like a vacation house) and there are fewer cars around, every year may be often enough.
Here are averages that could help you know how frequently you should replace the air filter at your residence:
- Vacation house or one occupant and no pets or allergies: every 6–12 months
- Ordinary 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