In this paper, the computational fluid dynamics technique (CFD) was used for air flow simulation in the solar chimney. The flow is assumed laminar, unsteady and incompressible. The air flow model consisted of a system of governing equations continuity, momentum, energy are solved for 2D Cartesian system uses the SIMPLE algorithm and the Power-Law differencing scheme. The influence of the variation depth of the solar chimney on the thermal efficiency of the system was studies. The principle of functioning of the system is visualized. The temperatures obtained on the level of the zone of occupation are adaptable to the interval of thermal comfort. The results of simulation are congruent with those of the literature. (c) 2011 Elsevier Ltd. All rights reserved.