#1 brand recommended by allergists;Helps capture certain airborne germs;Circulates room air up to 5 times per hour & AHAM CADR Rated 200 - Room Size: 17' x 18' (310 sq. ft.);Activated Carbon Prefilter helps reduce unpleasant odors;Easy tap electronic controls w/ 3 air cleaning levels plus Turbo Clean setting & 2, 4 & 8 hour timer. Electronic filter replacement reminders.