For Large Size Rooms 17 x 22#1 Choice of Physicians* The Honeywell True HEPA air purifier offers 3 powerful cleaning levels and can help reduce the amount of odors and airborne particles in large rooms. Its long-life True HEPA filter captures up to 99.97% of particles as small as 0.3 microns and typically only has to be replaced every three to five years. This powerful model effectively captures particles such as dust, tobacco smoke, pet dander and pollen from the air that passes through the filter. It also helps capture certain airborne germs such as bacteria and virus. The 50250-S has a 360 air intake for maximum efficiency and features a carbon pre-filter that prolongs the filter life by removing large particles before they can enter the HEPA filter and helps reduce common odors. br Honeywell is the #1 recommended air purifier brand by Allergistsbr Captures up to 99.97% of