Greentech Air Purifier Active HEPA+ Room with ODOGard®Transform your air quality. Active HEPA+ with ODOGard Room is the only purifier to combine both active and passive air purification technologies with the odor eliminating power of ODOGard. In addition to reducing volatile organic compounds (VOCs), allergens such as pollen and pet dander, and odors caused by mold, bacteria, and other pollutants, it actively improves air quality for a cleaner, fresher indoor environment.