With air purifiers their are typically 2 systems. One is where a fan pulls dirty air through a series of air filters and cleans the air. The other style is using Activated Oxygen or 03 which makes the air smell clean and nice but does not really remove the allergens from the air like the filter type of air purifiers. The great thing about this air purifier (and why its the best one for the money) is it is actually a perfect combination of both those systems. So its up to you and it can clean the air in nearly any situation! This high end New Comfort CA3000 Air Purifier has 6 stages of purification, washable filters, 3 year warranty, works up to 3000 square feet leaving your air clean and fresh. The 6 Stages of Filtration that keeps your air fresh and clean are: 1. HOSPITAL GRADE WASHABLE HEPA Filter. HEPA Filter is long Lasting WASHABLE filter. Perfect for removing allergens and dust from the air. 2. UV LIGHT - 3 ACTIVATED OXYGEN GENERATOR- May be turned on and off by user. For diminishing powerful Odors like smoke and other odors user may turn on the Activated Oxygen Ozone Generator in unoccupied spaces that keeps your air smelling clean and fresh. 4. Tio2 PHOTO CATALYTIC FILTER Can reduce mold spores, odors and bacteria causing diseases. 5. CHARCOAL FILTER Charcoal filters are proven to safely remove odors and from your air. 6. NEGATIVE ION FILTRATION ion generators remove contaminants such as smoke, pollutants, allergens,.