The purpose of the investigation presented in this study is to evaluate the tube side single phase heat transfer performance on the EXTEK (Twisted Multi-Head) tube. The geometry of the cross-section for a flow passage has an effect on its convective heat transfer capabilities. For concentric annuli in a double tube heat exchanger, the annular surface enhancement and tube profile enhancement play an important role. EXTEK (Twisted Multi-Head) uses twisted extrusion of a star shape tube for tube profile enhancement. The study was able to develop individual heat transfer coefficient correlations for this new method of enhancement for the turbulent flow regimes. A plain annulus was also investigated for comparison. The Wilson plot method was used to determine the tube side heat transfer coefficients from which the Nusselt type correlations were developed. © 2011 Asian Network for Scientific Information.