When deciding if you need to replace an air filter, you should consider a number of questions, including:
- What kind of filter do you have?
- Are there any pets in your home?
- How is your home’s indoor air quality?
- How many people live in your home?
- Is there any construction or other source of air pollution outside your home?
If you and your family are in good health, follow the manufacturer’s guidelines on a 1- to 3-inch filter, which typically advise replacement every 30 to 90 days. If you have allergies or pets, however, change your filters every 30-45 days, or use a more highly rated product.