Airflow and thermal comfort in naturally ventilated classrooms.

The airflow pattern and thermal comfort in a naturally ventilated classroom were predicted using CFD techniques. The CFD model for turbulent flow consists of equations for the conservation of mass, momentum and thermal energy and the equations for the k-E turbulence model, taking account of the effects of buoyancy and obstacles in the room. The thermal comfort was assessed according to the predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD). The mean radiant temperature for each grid point was calculated from the radiant heat balance for the classroom and the shape factor of the point. Thepredicted velocity and temperature distributions were compared with experimental results and reasonable agreement was achieved.It was found that occupants in the room have great influence on the airflow pattern and temperature distribution.