How regularly you should change your air filters can depend on the following:
- Air filter kind
- Complete 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 deal with from light to moderate allergies, you could get a better air filter or get new ones even more regularly.
Or, if you live a more remote location or less occupied residence (like a vacation home) and there are a reduced number of cars around, annually could be frequent enough.
Here are averages that could help you know how frequently you should replace the air filter at your house:
- Vacation house 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