The Triple Action series of Sharp Air Purifiers feature automatic air quality control. Watch this video to see the smart controls in action on a Sharp Plasmacluster Air Purifier (KC-860U).
The color monitor on the front displays the air quality – green for clean, yellow for dirty, and red for very dirty. When the air purifier senses dust or particles such as pet dander or pollen, it automatically adjusts fan speed to maximize air cleaning until particles are no longer detected – at which point the monitor turns green again and the fan returns to Low fan speed.
Auto Mode is a convenient way to have the air purifier clean at High fan speed only as necessary.