How frequently 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 usually instruct you to change them every 30–60 days. If you deal with from light to moderate allergies, you could install a better air filter or change them even more regularly.
Or, if you reside a more remote location or less occupied house (like a vacation home) and there are a reduced number of cars around, each year could be regular enough.
Here are averages that could help you figure out how regularly you should change the air filter at home:
- Vacation residence 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