Lin Z, Chow T T, Fong K F, Liu J P
Bibliographic info:
Hong Kong, City University, Division of Building Science and Technology, 2001, proceedings of IAQVEC 2001, "Indoor Air Quality, Ventilation and Energy Conservation in Buildings: Fourth International Conference", held Changsha, Hunan, China, 2-5 October, 2

One of the reasons for using displacement ventilation is that it may provide better indoor air quality in the occupied zone than conventional mixing ventilation. It is therefore important to understand the importance of the system on this aspect. A validated CFD model was employed to generate concentration distribution data for CO2, radon and moisture in a Hong Kong shop with displacement ventilation. Analysis found that the concentration distribution affected by factors such as the source type and location, its associated plume strength and human body convection, etc. The indoor Radon comes from building materials. The indoor CO2 and moisture are generated by the occupants. Because the upward free convection around a person brings the air from lower level to the breathing zone, the inhaled air is cleaner than the air at the same height. This effect is largely strengthened by the generally upward displacement airflow. Prediction of contaminant distribution is more difficult than air temperature and flow distribution.