Abstract: This is an apparatus that disinfects room air by destroying common allergens such as mold spore, dust mites, microbes, and VOCs, as well as dangerous substances, both organic and inorganic. Using photocatalytic oxidation, it places a continuing supply of the oxygen radical hydroxyl into a local environment. This helps prevent the spread of infectious diseases by destroying infectious microbes, contained in the droplet nuclei of human and animal respiration, as they float in the air. This apparatus also removes carbon monoxide, radon and other contaminants from the air by turning them into such harmless substances as carbon dioxide and water. It uses little energy, needs no filters, and operates silently.