How regularly you should change your air filters could depend on the following:
- Air filter model
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the house
For basic 1"–3" air filters, manufacturers often 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 change them even more often.
Or, if you reside a more country location or less occupied house (like a vacation residence) and there are a reduced number of cars around, annually could be regular enough.
Here are averages that might help you know how frequently you should change the air filter at your house:
- Vacation home 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