建築物開口對風壓通風影響之研究

Influence of Building Opening on Wind-Driven Cross Ventilation

風壓通風是依靠建築物內外的氣壓差異所造成的空氣流動，具有改善室內空氣品質、節約空調耗能的功效。但風壓通風會受到室外風速、風向及開口特性的影響，定量計算較為困難。本研究利用風洞模型實驗來研究風壓通風的影響參數，研究參數包括風速、風向角和通風開口的大小、形狀、紗網、百葉窗等對通風量和流量係數的影響。本研究並利用理論分析建立一個風壓平衡模式，此模式不需要使用複雜的計算流體動力學模式來預測風場，僅利用室外風速、風向、開口大小及室外壓力分佈便可計算穩態風場中，室內壓力與時間平均通風量，此模式將有助於建築師評估、規劃建築物自然通風之用 。

Wind-driven natural ventilation has been demonstrated to be a valid means to maintain a comfortable and healthy indoor environment, as well as an energy-saving alternative to mechanical ventilation. This study used theoretical and experimental approaches to investigate wind-driven cross ventilation. A series of experiments were carried out in a large-scale wind tunnel to examine the influences of wind speed, attack angle, size and shape of opening on the discharge coefficient of a building opening. In addition, a pressure balance model was developed to calculate the internal pressure and ventilation rate. The experimental results verified that the pressure balance model could accurately predict ventilation rates of various external wind speeds, attack angles, opening sizes and shapes.