How regularly you should install new air filters may depend on the following:
- Air filter model
- Complete indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the house
For basic 1"–3" air filters, manufacturers usually direct you to change them every 30–60 days. If you have from light to moderate allergies, you could get a better air filter or change them even more regularly.
Or, if you live a more country spot or less occupied house (like a vacation residence) and there are not as many cars around, yearly may be frequent enough.
Here are averages that may help you figure out how regularly you should replace the air filter at your residence:
- Vacation home or one occupant and no pets or allergies: every 6–12 months
- Ordinary suburban house without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days