How frequently you should change your air filters might depend on the following:
- Air filter type
- 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 direct you to replace them every 30–60 days. If you deal with from light to moderate allergies, you could install a better air filter or change them even more regularly.
Or, if you live a more country location or less occupied house (like a vacation residence) and there are a reduced number of cars around, yearly may be often enough.
Here are averages that could help you know how frequently you should replace the air filter at your residence:
- Vacation residence 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