Abstract: Three types of enhanced promoters were tested for forced convection heat transfer in a rectangular channel. Heat transfer characteristics were measured for the liquid with the range of reynlods between 2.2 ×10³ and 6.25×10³. Thress types of turbulence promoters, ete perforated ribi-type. shallow serrated rib-type. deep serrated rib-type were tested. Performance comparison was made of the heat transfer ability of the enhanced surfaces with turbulence promoters under the condition of constant blower power. It was found that the surfaces with shallow serated rib-type tubulence promoters showed better and the surfaces with depth serrated rib-type turbulence promoters showed best excellent performace.