How frequently you should replace your air filters might depend on the following:
- Air filter kind
- Complete indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the house
For basic 1"–3" air filters, manufacturers often direct 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 house (like a vacation house) and there are a reduced number of cars around, every year might be regular enough.
Here are averages that might help you figure out how regularly you should replace the air filter at your residence:
- Vacation home or single occupant and no pets or allergies: every 6–12 months
- Common 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