How frequently 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 residence
For basic 1"–3" air filters, manufacturers usually instruct you to change them every 30–60 days. If you have from light to moderate allergies, you could upgrade the air filter or get new ones even more regularly.
Or, if you live a more country area or less occupied residence (like a vacation home) and there are fewer cars around, yearly may be regular enough.
Here are averages that might help you figure out how often you should change the air filter at your house:
- Vacation house or lone occupant and no pets or allergies: every 6–12 months
- Average 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