The effect of a porous layer on thermal convection in a closed rotating square chamber has been studied in this paper. The left border of the chamber is heated up, the right one is cooled, and other walls are thermally insulated. The governing relations with the initial and boundary conditions written employing stream function and vorticity variables are worked out by the finite difference technique. Two approaches are considered and analyzed for setting the heat border conditions at the internal interface between clear liquid and porous material. The first approach assumes that the thermal flux is divided between two phases based on their effective conductivities and temperature gradients. The second model states that both phases at the interface obtain the same thermal flux as the wall. The performed analysis has shown possible differences between these models and the range of governing parameters when these models allow to obtain the similar results.