The thermal dispersion and heat-transfer processes in the thermally-developing region of a sintered porous metal channel with asymmetric heating are analyzed by a two-equation model. The two-equation model considers different energy equations for the bronze and air due to the large difference in their thermal conductivities. In order to account for the large heat-transfer characteristics caused by the growth of thermal boundary layer in the thermal entrance region, the thermal dispersion conductivity is modeled as the product of an entrance-effect function, the dispersive length and the Peclet number. The empirical coefficients in the entrance-effect function are determined by comparing the experimental data. From the calculated results it is found a two-equation model underpredicts the Nusselt number if the thermal-entrance effect function is not included in the model. A parametric study is also conducted to investigate the effect of Peclet number and thermal conductivity ratio on the calculated Nusselt number distribution.