How often you should install new air filters might depend on the following:
- Air filter model
- Total 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 get a better air filter or replace them even more regularly.
Or, if you live a more country spot or less occupied residence (like a vacation house) and there are fewer cars around, each year could be often enough.
Here are averages that may help you know how often you should change the air filter at your residence:
- Vacation home or one occupant and no pets or allergies: every 6–12 months
- Ordinary 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