How often you should install new air filters might depend on the following:
- Air filter kind
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the house
For basic 1"–3" air filters, manufacturers typically direct you to get new ones every 30–60 days. If you suffer from light to moderate allergies, you could get a better air filter or get new ones even more frequently.
Or, if you live a more rural area or less occupied residence (like a vacation house) and there are not as many cars around, each year may be often enough.
Here are averages that could help you know how regularly you should replace the air filter at your house:
- Vacation home or single occupant and no pets or allergies: every 6–12 months
- Common suburban house without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days