Effective heat transfer is essential in a variety of energy technologies in order to enable the maximum possible power density and power conversion efficiency needed for economic competitiveness and fuel conservation. A particularly difficult heat transfer problem exists with gas coolants, due to their inherently low heat capacity and heat transfer coefficient. Innovative techniques have been proposed previously using porous metal heat transfer media infiltrated by the coolant. The general design strategy is to minimize the coolant flow path length in contact with the porous medium, and to minimize the friction factor in that zone while simultaneously maximizing the heat transfer coefficient. In this work we seek to develop improved phenomenological thermal-hydraulic models in order to assess various porous heat transfer media and to help optimize the heat transfer coefficient while minimizing the associated fluid friction in innovative design concepts. The results will be applied to the field of fusion energy research, where extreme thermal conditions exist and gas coolants are favored due to their inherent safety features.