层式通风——高温空调下的出路

Ventilation system for higher room temperature setting

节能减排是当前全球性的呼声。作为回应,东亚区域的若干个政府都提倡采用更高的夏季空调温度。要推广高温空调,就必须使公众相信,这样做不会降低室内环境品质,尤其是不会降低热舒适性。要实施高温空调,就必须筛选出在这样的非常规工况下性能良好的通风系统。因其在较高室温下的良好性能,本文以数间香港办公室为例,介绍并分析一种新型通风系统——层式通风。实验和模拟计算的结果显示,如果送风速度,送风量和送、排风口的设计正确,层式通风具有热舒适性好(具体表现为头脚温差小)、能耗低、特别是呼吸区空气品质好的特点。下一步的工作将对上述优点进行定量研究。

There is worldwide plea to reduce carbon dioxide emission.In response to such a call,several governments in the East Asia recently required to adopt higher room temperatures in summer.To promote such an idea,the public need to be convinced that such practice would not sacrifice indoor environmental quality,especially thermal comfort of the occupants.To implement such a measure,suitable ventilation system(s)to work under the unconventional conditions should be identified.Stratum ventilation is introduced to demonstrate its feasibility in coping for the higher room temperatures.A case study,a typical office in Hong Kong,is used to illustrate the performance of this new ventilation mode.Experimental and computational results show that with properly designed supplied air velocity and volume,locations of supply and exhaust,the proposed system has the potential to maintain better thermal comfort with a smaller temperature difference between the head and foot level,lower energy consumption, and better indoor air quality(IAQ)in the breathing zone.Much further work is needed to determine if the benefits are significant.