This paper focuses on determining thermal conductivity in porous media using symmetry and asymmetry models. Since porous media are not uniform and homogeneous in most of the cases, anisotropy must be taken into account, what derives in the application of an asymmetry model as thermal gradients are not equal in all directions. The paper demonstrates that, under certain conditions, isotropic conditions, therefore, symmetry model can be applied to non-homogeneous or uniform porous media. The paper also proves that as external power and temperature increases the symmetry model is no longer valid, being necessary to apply the asymmetry model that takes into account convection effects. The comparison between symmetry and asymmetry model results allows determining the influence of convective cells. The proposed algorithms can be used to calculate thermal conductivity at any conditions, say external power or operational temperature. Thermal conductivity at the starting up point can be determined using symmetry model, using the asymmetry model for higher temperatures. The modeling has been validated comparing experimental data and estimated values, within a very good accuracy, higher than 99% in all cases.