The Sharp KC-850U Plasmacluster Air Purifier with Humidifying Function purifies a room up to 254 square feet. It offers a unique combination of air treatment technologies to make you more comfortable, whatever the season. Bacteria, germs, mold spores, pollen, pet dander, smoke, dust and odors can make breathing harder, especially for asthma and allergy sufferers. Sharp's KC-850U Plasmacluster air purifier helps remove these irritants with an ultra quiet fan that draws air through a 3-stage filter system. This filter system plus the revolutionary Plasmacluster Ion Technology for air purifiers makes the air healthier and cleaner smelling. For an even more comfortable environment, sensors constantly monitor the air quality in your room, adjusting the fan for air purity while providing the optimum humidity level. This combination of features is a smart way to choose cleaner, healthier, more breathable air.