How regularly you should change your air filters may depend on the following:
- Air filter kind
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the residence
For basic 1"–3" air filters, manufacturers typically instruct you to change them every 30–60 days. If you suffer from light to moderate allergies, you could upgrade the air filter or replace them even more often.
Or, if you live a more remote spot or less occupied residence (like a vacation residence) and there are fewer cars around, each year may be frequent enough.
Here are averages that could help you decide how frequently you should get a new air filter at your house:
- Vacation house or one occupant and no pets or allergies: every 6–12 months
- Ordinary suburban home without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days