The CFD is an effective method for investigating air distribution and thermal conditions in large industrial buildings. CFD computing cost is a major concern for industrial simulation, in which CFD grid number plays a dominant role. The mesh type and size are critical on determining the cost of computation and the accuracy of the numerical results. The study uses several different industrial applications to analyze the influence of grid on CFD prediction. The research provides some guidelines on how to control the grid quality to obtain a reasonable accuracy while shorten the computing time for industrial applications