How frequently you should replace your air filters might depend on the following:
- Air filter model
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the house
For basic 1"–3" air filters, manufacturers typically direct you to change them every 30–60 days. If you have from light to moderate allergies, you could get a better air filter or get new ones even more often.
Or, if you reside a more country area or less occupied residence (like a vacation house) and there are a reduced number of cars around, yearly may be regular enough.
Here are averages that could help you decide how frequently you should change the air filter at your residence:
- Vacation house 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