The Sharp KC-850U Triple-Action 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 and your family more comfortable whatever the season. Sharp s Plasmacluster air purifier helps remove 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 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 fresher household air.