建築物通風之目的在於提供居住者所需的新鮮空氣、降低室內溫度與污染物濃度,達到舒適的室內環境。台灣濕熱的氣候狀況,使得許多建築物不分季節、不分晝夜地使用冷氣空調來維持建築物室內環境的舒適性,而耗費大量的電力。若能有效地利用自然通風協助或維持室內居住環境和空氣品質,將可達到建築節能之目的。本研究結合理論模式、CFD數值模式與風洞實驗結果,發展一套風壓通風的計算模式,可考慮風向、紗窗、縱深、不透風之陽台以及相鄰建築物對風壓通風的影響,並藉由一個單一樓層住宅案例有系統地說明風向、開口面積、位置及室內隔間對建築物自然通風量的影響。研究成果顯示:建築物自然通風所造成的小時換氣率ACH愈大,室內氣溫因被室外空氣置換而降氣的速率愈快,便不需要使用冷氣空調來降溫。亦即建築物自然通風狀況下的各區塊的平均換氣率ACH可做為評估住宅建築物自然通風潛勢良窳之標準。
This study employsa theoretical model, wind tunnel experiments and a Computational Fluid Dynamics (CFD) model to investigate the natural ventilation potential of residential buildings. The effects of wind direction, window screen, balcony, building length and adjacent buildings are considered by the present model. Then the modelis employed to systematically investigate the natural ventilation of a residential building. The simulation results reveal that the ventilation rate of buildings with the internal doors closed is much smaller than that of building with all the windows and doors are open. In addition, the average air change rate, ACH, of the building under the natural ventilation condition can be used to assess the effectiveness of the natural ventilation for buildings cooling.