How frequently you should install new air filters can depend on the following:
- Air filter model
- Complete indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the residence
For basic 1"–3" air filters, manufacturers typically tell you to replace them every 30–60 days. If you have from light to moderate allergies, you could upgrade the air filter or change them even more often.
Or, if you reside a more country spot or less occupied house (like a vacation house) and there are fewer cars around, every year could be frequent enough.
Here are averages that could help you figure out how often you should replace the air filter at your residence:
- Vacation home or single occupant and no pets or allergies: every 6–12 months
- Common 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