The integration of building energy simulation (ES) and computational fluid dynamics (CFD) programs can provide more accurate prediction of building energy use and indoor environment due to the complementary information provided by the two programs. This paper outlines briefly a coupled energy simulation and computational fluid dynamics program with different coupling methods and validates the coupled program by using four sets of experimental data from literature. The comparison of the simulated results with the experimental empirical data reveals the advantages of the integrated building simulation over the separated energy simulation and computational-fluid dynamics applications. The program was then used to calculate the cooling load of a large-scale indoor auto-racing complex.