How regularly you should install new air filters can depend on the following:
- Air filter kind
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the residence
For basic 1"–3" air filters, manufacturers usually instruct you to change them every 30–60 days. If you deal with from light to moderate allergies, you could upgrade the air filter or get new ones even more frequently.
Or, if you reside a more country area or less occupied residence (like a vacation home) and there are fewer cars around, annually may be frequent enough.
Here are averages that might help you figure out 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 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