The energy consumption of AC (air conditioning) systems in large buildings is normally higher than the energy consumption in smaller buildings, and its indoor air flow field is also more complex than that in small building. To study the air flow mode and the indoor air flow fields in large spaces is of great significance to the energy conservation of AC systems and thermal comfort of the occupants. This paper presents an example using a large building that uses stratified air conditioning delivered through the linear slot sidewall diffusers and perforated sidewall diffusers. Using CFD simulation methods, three air flow field situations were simulated: (1) total air volume supplied from linear slot diffusers located in the middle of a side wall, (2) 50% flow through the linear slot diffusers the remainder supplied through the perforated sidewall diffusers, (3) 30% of the volume supplied with linear slot diffusers, 70% supplied through the perforated sidewall diffusers. The simulated results show that the third airflow mode is the optimal one for the three modes, which is good for achieving energy conservation and a comfortable building thermal environment in buildings with large spacial areas.
