How frequently you should change your air filters can depend on the following:
- Air filter kind
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the house
For basic 1"–3" air filters, manufacturers usually tell you to install new ones every 30–60 days. If you have from light to moderate allergies, you could install a better air filter or replace them even more regularly.
Or, if you live a more remote spot or less occupied residence (like a vacation home) and there are a reduced number of cars around, annually could be regular enough.
Here are averages that could help you know how regularly you should get a new air filter at your house:
- Vacation residence 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