The Clean Comfort® CC-HEPA Return Duct or Return Remote Collar Mount system has three stages of filtration, a ventilator, a speed selection switch, and a cabinet enclosure system. The ventilator pulls air through the pre-filter and then through the impregnated carbon pad for odor control. Finally, the last stage of filtration is the HEPA filter, which removes 99.97% of particles 0.3um in size that pass through the filter*.
*Independent testing performed by LMS Technologies, Inc.