Noise levels vary depending on the type of model you choose, but typically most models are designed to be as quiet and unobtrusive as possible. Many models also come with adjustable fan speeds that allow you to adjust the noise level based on your needs. Generally, the higher the motor speed, the louder the air cleaner. It's important to remember that regardless of how quiet an air cleaner may be, it is still essential for maintaining good indoor air quality by capturing airborne particles like mold spores and other allergens. Investing in a quality model can help ensure that you're getting optimal performance with minimal noise.