Field study on the ventilation effectiveness and thermal comfort in a concert hall with displacement ventilation system.

The purpose of this study is to identify the ventilation effectiveness of a displacement ventilation system in a concert hall with 501 seats, where a large amount of outside air is required for ventilation. Displacement ventilation was considered appropriate to reduce the amount of outside air. Light bulbs were placed on all the seats to simulate the heat source from the audience. From the measured concentrations, the local mean age of air at the breathing point with the displacement ventilation system was found around one third of that of the fully mixed condition. No significant difference was found in local mean age of air on horizontal distribution in the occupied zone. The measured results of horizontal temperature distribution were almost uniform, while those of vertical temperature distribution were within an acceptable range in the occupied zone and quite high above it. The experimental findings suggest that the displacement ventilation system can be adequately operated with a relatively high cooling load to provide acceptable conditions of indoor air quality.