How regularly you should replace your air filters can depend on the following:
- Air filter kind
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the house
For basic 1"–3" air filters, manufacturers often instruct you to get new ones every 30–60 days. If you suffer from light to moderate allergies, you could get a better air filter or get new ones even more regularly.
Or, if you reside a more remote location or less occupied home (like a vacation house) and there are fewer cars around, annually could be frequent enough.
Here are averages that might help you figure out how often you should change the air filter at home:
- Vacation residence 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