How frequently you should install new air filters could 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 often tell you to get new ones every 30–60 days. If you deal with from light to moderate allergies, you could get a better air filter or change them even more regularly.
Or, if you're in a more remote spot or less occupied home (like a vacation residence) and there are a reduced number of cars around, annually could be often enough.
Here are averages that could help you know how often you should change the air filter at your residence:
- Vacation residence or lone occupant and no pets or allergies: every 6–12 months
- Average 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