Computer simulation played a key role in the optimization of a displacement ventilation system in a school auditorium by helping to reconfigure the locations of the diffusers and the exhausts in order to eliminate unnecessary air flow. Displacement ventilation systems, which locate the air supply on the floor instead of the ceiling, are gaining popularity in North America because they are more efficient and require less energy to maintain a given level of comfort. However, displacement ventilation systems are generally more difficult to design due to several inherent issues like the need to avoid temperature gradients and drafts with the air supply located near the people.