How often you should install new air filters might depend on the following:
- Air filter type
- 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 instruct you to replace them every 30–60 days. If you deal with from light to moderate allergies, you could install a better air filter or replace them even more frequently.
Or, if you reside a more rural location or less occupied residence (like a vacation home) and there are a reduced number of cars around, annually may be regular enough.
Here are averages that can help you know how regularly you should get a new air filter at your residence:
- Vacation residence 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