Abstract: A new and improved air purifying apparatus having a housing that is adapted to be mounted in-line with an air duct, such as a return air duct of an air-conditioning system. The housing is designed for easy installation without modifying the existing air-conditioning duct work. An ultraviolet light-emitting device is positioned within the housing for radiating the air passing through the return air duct with UV-C and UV-V radiation to destroy air borne chemical and biological odors, bacteria, and microorganisms. A high flow pleated air filter is provided and is removably positioned within the housing for removing air borne particulate material such as dust and pollen.