CFD SIMULATION OF CONCENTRATION OF GASEOUS IMPURITIES IN A TYPICAL HONG KONG SHOP

摘要

One of the reasons for using displacement ventilation is that it may provide better indoor air quality in the occupied zone than mixing ventilation. It is therefore important to understand the performance of the latter on this aspect for comparison. A validated CFD model was employed to generate concentration distribution data for CO_2, radon and moisture in a typical Hong Kong shop with mixing ventilation. Analysis found that the concentration distribution affected by factors such as the source type and location and its associated plume strength and human body convection, etc. The indoor Radon comes from building materials. The indoor CO_2 and moisture are from 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. Prediction of contaminant distribution is more difficult than air temperature and flow distribution.