Experiments were conducted to investigate the performance of an axial flow tubular heat exchanger with a novel swirl flow of air created by the addition of circular baffle plates featuring trapezoidal air deflectors with various inclination angles. The tubes remained in identical longitudinal arrangement and maintained constant heat flux over their surface. Each baffle plate contained four deflectors with an equal inclination angle, generating an air swirl inside the circular duct containing the heated tubes that improved the air-side turbulence and thus the rate of heat transfer from the tubes' surfaces. The pitch ratio of the baffle plates was varied, and the Reynolds number was kept in the range of 16000–28000. Results from the study showed an average 7.4% improvement in performance enhancement criteria when the exchanger was fitted with a baffle plate featuring a deflector inclination angle of 30° and operated under counter flow conditions when compared to a parallel flow arrangement operating under similar experimental conditions.