How often you should replace your air filters might depend on the following:
- Air filter model
- 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 direct you to change them every 30–60 days. If you suffer from light to moderate allergies, you could get a better air filter or replace them even more regularly.
Or, if you live a more country area or less occupied residence (like a vacation residence) and there are a reduced number of cars around, each year may be often enough.
Here are averages that could help you know how frequently you should replace the air filter at your house:
- Vacation home or single occupant and no pets or allergies: every 6–12 months
- Common suburban residence without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days