How regularly you should change your air filters could depend on the following:
- Air filter type
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the home
For basic 1"–3" air filters, manufacturers typically instruct 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 change them even more regularly.
Or, if you reside a more country spot or less occupied home (like a vacation residence) and there are not as many cars around, each year might be regular enough.
Here are averages that might help you figure out how often you should replace the air filter at your residence:
- Vacation home or single occupant and no pets or allergies: every 6–12 months
- Common 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