How frequently you should replace your air filters may depend on the following:
- Air filter model
- Complete indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the residence
For basic 1"–3" air filters, manufacturers usually tell you to get new ones every 30–60 days. If you have from light to moderate allergies, you could get a better air filter or change them even more regularly.
Or, if you live a more country spot or less occupied home (like a vacation house) and there are not as many cars around, yearly could be frequent enough.
Here are averages that might help you figure out how frequently you should replace the air filter at your house:
- Vacation home or lone occupant and no pets or allergies: every 6–12 months
- Average suburban house without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days