How regularly you should change your air filters can depend on the following:
- Air filter type
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the residence
For basic 1"–3" air filters, manufacturers often tell you to change them every 30–60 days. If you have from light to moderate allergies, you could install a better air filter or get new ones even more regularly.
Or, if you're in a more rural area or less occupied house (like a vacation house) and there are a reduced number of cars around, every year might be regular enough.
Here are averages that can help you figure out how often you should change the air filter at home:
- Vacation house or lone occupant and no pets or allergies: every 6–12 months
- Average 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