This paper numerically investigates the heat transfer enhancement using rectangular winglet pairs in a fin-and-tube type heat transfer surface having five inline rows of tubes. The influence of number of winglets, attack angles of the winglets, and their location has been analyzed under laminar flow conditions with Reynolds number ranging 400–1500. To account for the combined effect of heat transfer enhancement and pressure drop penalty, an enhancement factor is also discussed by changing the winglet pair's number and location. The numerical results show that pressure drop can be reduced significantly by placing the winglet more toward the exit of the flow channel. Streamwise distance and spanwise distance of the winglet pairs have been investigated for maximum enhancement factor. The numerically obtained results show that the winglets number and their placement at different locations have a major influence on enhancement factor. The results show that both the heat transfer and the pressure drop increase with an increase in attack angle of the winglets and best angle for the highest enhancement factor has been found out. Correlations have been developed for streamwise distance, spanwise distance, and angle of attack for different range of Reynolds numbers.