How regularly you should change your air filters might depend on the following:
- Air filter type
- Total 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 have from light to moderate allergies, you could install a better air filter or change them even more regularly.
Or, if you reside a more rural spot or less occupied residence (like a vacation house) and there are not as many cars around, yearly may be often enough.
Here are averages that could help you know how regularly you should get a new 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