A numerical study of natural convection in a vertical channel partially filled with a porous matrix is performed. The flow is described using Brinkman-extended Darcy model. The governing equations are solved by using the finite-volume method. The pressure-velocity coupling is provided by the SIMPLER algorithm. The objective of this work is to determine heat transfer and fluid flow characteristics for Prandtl number Pr = 0.71. A parametric study was conducted by varying the thicknesses of the porous layers and Darcy Number for two Rayleigh number Ra = 106 and Ra = 107. The isotherms, streamlines, average Nusselt number and dimensionless temperature are presented for different parametric study.