Abstract: An air flow system for use in ambulance is generally comprised of a blower unit mounted in the ceiling of the ambulance's patient compartment, an air conditioning condenser, and a series of exhaust vents extending through the sidewalls of the patient compartment and positioned adjacent the floor. The exhaust vents each include a fan mounted therein for drawing the air in the patient compartment thereto and forcing the air out of the compartment. The blower unit includes louvers to permit selective air direction control, but essentially the blower unit always directs the conditioned air vertically downwardly over a patient supported on a stretcher, thereby creating an air curtain around the patient.