Abstract: The S/P model, an integral model for calculating cooling tower plume rise developed in German guidelines, is introduced. The rise of a cooling tower plume is computed for different air stabilities and different wind velocities with the corresponding control data. The parallel plume rise of gas from a chimney or a cooling tower is calculated. The results show that, in the soft wind condition the rise from a cooling tower is remarkably higher than the rise from a chimney because of its heat release. An example result shows that, under extremely unstable air condition with wind velocity greater than 4.5 m/s, the rise from a cooling tower is lower than that from a chimney.