How frequently 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 house
For basic 1"–3" air filters, manufacturers typically 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 change them even more regularly.
Or, if you're in a more remote spot or less occupied home (like a vacation residence) and there are not as many cars around, yearly could be often enough.
Here are averages that could help you know how often you should change the air filter at your residence:
- Vacation house or lone occupant and no pets or allergies: every 6–12 months
- Average 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