The Vornado AC300 Whole Room Air Purifier uses true HEPA filtration, the most effective filtration available, to remove up to 99.97% of airborne allergens down to 0.3 micron in size. The Vornado Whole Room Purifier actively circulates and filters all the air throughout a room. It uses a radial blower to intake and clean all the air in the room- up to 220 sq. ft. Precision engineering allows the blower to operate quietly, despite it's powerful air flow. The AC300 uses a combination of HEPA and carbon filtration to trap Dust, Pollen, Pet Dander, Smoke, Bacteria, Mold Spores, Dust Mites and more. The carbon prefilter both adsorbs odors and traps larger particles.