How frequently you should change your air filters may depend on the following:
- Air filter model
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the home
For basic 1"–3" air filters, manufacturers usually instruct you to install new ones every 30–60 days. If you suffer from light to moderate allergies, you could upgrade the air filter or change them even more regularly.
Or, if you live a more rural location or less occupied residence (like a vacation residence) and there are a reduced number of cars around, each year may be frequent enough.
Here are averages that could help you decide how frequently you should replace the air filter at your residence:
- Vacation home 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