The Sharp Plasmacluster Ion Air Purifier with True HEPA Filter effectively reduces pollen, dust, pet dander, smoke, germs, bacteria, viruses, odors, mold, and fungus in your living space. There is a three-stage filter system including a permanent micro-mesh pre-filter, activated carbon filter, and long-life True HEPA filter, which captures 99.97% of particles as small as 0.3 microns from the air that passes through it. Patented Plasmacluster Ion Technology disperses positively and negatively charged ions throughout the room to safely break down microorganisms and odors (even those trapped in fabric, carpeting, and drapery!). It is an ideal solution for allergy sufferers, asthmatics, pet owners, and smokers, and best used in a bedroom, living room, study, or exercise room. There are 3 manual fan speeds. The unit has LibraryQuiet operation (as quiet as 29 decibels, or the sound of rustling leaves) and is ENERGY STAR rated, so you can run the unit continuously while saving money and energy.