This paper presents transient heat transfer characteristics of an effective energy conversion between high-temperature gas enthalpy and thermal radiation by means of porous media. A theoretical analysis is conducted for the one-dimensional system where conduction, convection and radiation take place simultaneously. The porous medium is assumed to be a homogeneous continuum which absorbs and emits thermal radiation. The coupled energy equations for gas and porous media are solved numerically. To confirm the validity of the analysis, experiments which strictly correspond to the analytical model are performed. The predicted results agree well with those of the experiments.