How frequently you should install new air filters might depend on the following:
- Air filter model
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the house
For basic 1"–3" air filters, manufacturers usually tell you to change them every 30–60 days. If you have from light to moderate allergies, you could install a better air filter or change them even more regularly.
Or, if you live a more country spot or less occupied residence (like a vacation house) and there are not as many cars around, each year could be regular enough.
Here are averages that can help you decide how often you should change the air filter at home:
- Vacation residence or lone occupant and no pets or allergies: every 6–12 months
- Average 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