Get $50 Discount On Therapure Air Purifier At Bestbuy.com. Combining filter cleaning with a UV lamp, this purifier efficiently kills airborne germs while keeping the air clean. A convenient 24-hour timer lets one run the unit when he want. The 212 sq. ft. room capacity easily cycles fresh air throughout an average sized bedroom. A light indicator turns on when the filter needs to be replaced. The filter reduces allergens, pollution, smoke, and odors, while a photocatalyst filter helps reduce fumes and chemicals.