The Hunter 30400 QuietFlo True HEPA Air Purifier features a QuietFlo Fan that draws air into the unit without excessive noise. An advanced activated carbon prefilter reduces cooking, tobacco and pet odors while also capturing larger dust particles, lint and pet hair from dirty air. A True HEPA filter element captures 99.97% of all airborne particles as small as 0.3 microns in size that pass through the filter. Effective Quiet-Flo design exhausts clean, purified air back into the room from the top of the unit to avoid disturbing settled particles.