DESC: Introducing Honeywell's Quietest Air Purifier Ever! This Silent-Comfort Ultra-Quiet HEPA Air Purifier from Honeywell features No Draft airflow technology which effectively and quietly cleans the air without producing a cool exhaust draft. Patent-pending ultra-quiet high speed operation combined with a True HEPA filter makes Honeywell the #1 Choice of Physicians. Ideal for Medium-Large bedrooms and family rooms up to 11' x 17'. Enviracaire 18150 Features and Benefits: Advanced Airflow Design-for ultra quiet high-speed operation. Recommended for a 11' x 17' room, 6 air changes per hour. True HEPA filter helps capture 99.97% of airborne particles and allergens as small as 0.3 microns from the air. SurroundSeal HEPA filter technology helps prevent unfiltered air from leaking around the HEPA filter. Large filter area for long filter life and low maintenance.