This article studies the thermal comfort control strategy of an indoor environment by computational fluid dynamics (CFD) software. It intends to show the capabilities of the CFD in modeling and predicting the room air dynamics. A room model with an exposed wall has been built to simulate the temperature　 distribtions under different load conditions. The comfort is measured by a combination of the air temperature, radiant temperature and air velocity . The system controls the comfort of the environment by monitoring the wall temperature and the exhaust air temperature and it is able to provide a stable comport environment to the occupants.