Numerical Study Of The Effect Of Air Terminal Layouts On The Performance Of Stratum Ventilation System

摘要

It has been found that air terminal layouts could affect ventilation performance in a room. As a new air distribution system, stratum ventilation was proposed to accommodate elevated room temperatures. Its performance with various air terminal layouts was investigated by numerical method in this research. Totally four different exhausts locations were studied to determine the optimal exhaust locations. Exhausts were located at (a) middle level of the wall opposite to the supplies; (b) low level of the same wall of the supplies; (c) low level of the wall opposite to the supplies and (d) the ceiling level, respectively. Ventilation performances were evaluated by airflow pattern, temperature distribution, percentage of dissatisfied (PD) people due to draft, effective draft temperature (EDTs) and local mean age of air. The computational predictions were validated by experimental results. From the results, similar performance with exhausts located at middle or low level of the wall opposite to the supplies was observed. In case with exhausts located at the ceiling level, temperature and EDTs in occupied zone is relatively low. However, with this arrangement more fresh air could be supplied to the breathing zone. Better performance is found in case with exhausts located at low level of the same wall with supplies. Indoor environment could achieve thermal comfort and good air quality. This arrangement also helps to save the space for system installation. It is therefore a better choice for stratum ventilation design if performance requirements are met.