A Study on Stack Effect and Natural Ventilation in Atriums

本文旨在探讨冬季中庭热不适的烟囱效应，以及秋季中庭整体降温或夏季玻璃屋顶附近中庭顶部热空间降温的自然通风方式。1.高层办公建筑中庭热环境及空气流动实测分析：整个中庭都覆盖着玻璃。在夏季，中庭顶部的空气温度会上升到60摄氏度，来自热玻璃屋顶表面的辐射会导致热不适。中庭顶部的自然通风非常重要。在冬季，大量的室外空气通过入口进入中庭，导致中庭内空气温度降低。2.室外空气向电梯井道的流动及电梯井道的泄漏影响因素分析：通过测量室外、中庭、电梯厅和电梯井道的压力，估算了烟囱效应引起的电梯井道空气流入量。3.通过收集文献和向设计人员发放问卷调查，对已建成的玻璃幕墙建筑进行了调查：通过对文献记载的近500个中庭的分析，探讨中庭空间类型、空间高度、建筑面积、玻璃面积、通过对中庭设计者问卷调查的分析，明确了目前流行的自然通风和抑制烟囱效应引起的室外空气流入中庭的热环境控制方法。

The purpose of this report is to investigate stack effect which causes thermal discomfort in atriums in winter seasons and to investigate natural ventilation which cools overall the atrium space in autumn seasons or cools the hot space at the top of atrium near the glass roof in summer seasons.1.An analysis of thermal environment and air movement measured in an atrium attached a high-rise office building : This atrium is overall covered with glasses. In summer, the air temperature at the top of the atrium increases until 60ﾟC and radiation from the hot glass roof surfaces causes thermal discomfort. Natural ventilation at the top of the atrium is very important. In winter, a large amount of outdoor air flows into the atrium through entrance openings and causes air temperature decrease in the atrium.2.An analysis of the air flow from the outdoor to the elevator shafts and the leakage tactors of the elevator shafts : Air flow rate into the elevator shafts caused by stack effect is estimated using measurements of pressure at the outdoor, the atrium, the elevator hall and the elevator shafts. The leakage factors of elevator shafts are estimated too, using measurements.3.An investigation of already constructed glass-covered architectures from collecting literature and from sending out questionnaires to designers : About 500 atriums recorded in the literature are analyzed for the purpose of surveying the tendency of space type, space height, floor area, glass area, space use etc. An analysis of the questionnaire reply from the atrium designers makes clear popular controll methods of thermal environment involving natural ventilation and restraint of out door air flow into atriums caused by stack effect.