Abstract: A self contained air purification system includes an upright enclosed housing defining a germicidal chamber. A primary filter having a normally upstanding longitudinal axis has outer and inner peripheral surfaces, an interior plenum, and is supported on a base member. The housing has air inlets proximate the filter and air exhaust louvers in an upper member. Ultraviolet germicidal irradiation lamps are disposed in the germicidal chamber, and a resiliently mounted fan overlies the primary filter for drawing unclean air from the environment into and through the air inlets, through the primary filter, through the plenum and then into the germicidal chamber in a vortex-shaped whirling mass air stream flowing in a protracted course around and past the irradiation lamps for maximized exposure to the lamps, a purified air stream being discharged, after a final filtration, through the air exhaust louvers, then is returned to the environment.