To reduce the costs of building operation, it is necessary to provide for the use of energy-saving technologies at the stage of building design. This allows efficient use of material and energy resources, minimize costs during the design and construction of buildings and structures. One of the energy-saving technologies widely used in construction is the use of ventilated facade systems. Its application in difficult climatic conditions of many regions of Russia requires improvement and refinement of the existing methods of calculation of influence of temperature stresses in elements on strength characteristics of system, ways of the account of influence of air exchange in a backlash. The aim of the work is to determine the velocity of air flow in the gap of a ventilated facade with different width of the gap, the height of the building and climatic conditions by the method CFD (Computational Fluid Dynamics) - simulation of convective heat flux.