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