Steady-state, laminar natural convection flow characteristics inside a two-dimensional horizontal enclosure with flush-mounted discrete heat sources (DHSs) on the walls is numerically investigated. Two-dimensional laminar numerical simulations are obtained by solving the full elliptic governing equations using a finite volume based computational fluid dynamics (CFD) code. The heat and fluid flow structures are examined using velocity vector and isotherm contour plots. Enclosure wall and heater temperatures are fixed. Six different cases are investigated with different locations of DHSs. It is observed that DHS locations significantly alter the natural convection flow pattern. For each case investigated different air movement characteristics were obtained.