How regularly you should change your air filters may depend on the following:
- Air filter type
- 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 instruct you to change them every 30–60 days. If you deal with from light to moderate allergies, you could upgrade the air filter or get new ones even more frequently.
Or, if you reside a more country area or less occupied house (like a vacation house) and there are not as many cars around, yearly could be regular enough.
Here are averages that could help you know how often you should replace the air filter at home:
- Vacation home or single occupant and no pets or allergies: every 6–12 months
- Common 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