How often you should install new air filters might depend on the following:
- Air filter kind
- Total 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 get new ones every 30–60 days. If you deal with from light to moderate allergies, you could install a better air filter or replace them even more frequently.
Or, if you live a more country location or less occupied house (like a vacation residence) and there are fewer cars around, each year might be often enough.
Here are averages that may help you know how often you should change the air filter at your house:
- 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