A CFD simulation of airflow and temperature field in a heated room has been described in the paper. The tracking of pollutant particle movement is also presented here. The comparisons between computation and experiment show good and acceptable agreement. It can be concluded that CFD prediction can capture the main features of convective flow and provide satisfactory results. It can be seen that the thermal wall jet created by a radiator greatly influences the airflow pattern, temperature and pollutant particle distribution in the heated room. It can also be seen that the area close to the heat source has a high risk of air-borne contamination and imposes a harmful effect on the occupant.