A Three-dimensional unstructured control volume finite method is developed to simulate unsteady coupled heat and mass transfer phenomena that arise during convective drying of unsaturated porous media.  In order to simulate 3D geometries, as application here the drying of clay brick portion, we developed a Fortran code based on 3D unstructured meshes generated by the free mesh generator Gmsh.. Several simulation results are presented and depict the effect of the variability of heat and mass transfer coefficients. These simulations prove that only three-dimensional model is able to capture the effect of variability of heat and mass transfer coefficients.