街道尺度與建築配置對室内自然通風效益之影響

The Effects of Different Building Layouts on Indoor Ventilation Performance

近年因都市熱島效應與極端氣候之影響，減少能源消耗且適應環境之建築設計思維已成為現今主流，以德國為起點，歐美亦已推動被動式建築（Passivhaus），台灣亦有綠建築政策鼓勵建築提高所使用資源效率，與減低對環境與人體健康之影響，被動式建築也逐步在推廣。而若是在都市設計階段即考慮到建築與環境之關係，後續再推動被動式建築或是綠建築政策則會有更好的節能效率與適應環境之能力。在都市環境中，自然通風之效益較差，而室內自然通風之效益除了與建築配置相關外，亦受外部街道環境影響，故本研究探討建築配置對於室內通風效益之影響。研究結果得知，主要建築配置方位與該地區之主要風向呈45º角，室內通風效益為最佳；街谷高寬比（H/W）越高則室內通風效益越佳，但相對其街道中的迴流區亦較高，因此建議需有其他配套設計解決街道通風效益較差之問題；不同建築配置情況下，平行配置與錯列配置之室內通風效益趨勢相似，但在街谷中造成之流況不同，平行配置風流況較穩定具規律性，但高H/W情形下縮流效應明顯，錯列配置受渦流影響風流況較不穩定，但縮流效應相對較低。

 

Decreasing energy consumption and adapting to environments have become the mainstream architectural design concepts in response to the recent urban heat island effect and climate changes. The Passivhaus (i.e., passive house) concept, which was developed in Germany, has been promoted in Europe and North America. Similarly, green building policies have been implemented in Taiwan to promote resource efficiency in constructions and to reduce their impact on the environment and human health. Passivhaus are also being promoted in Taiwan. In urban planning, considering the relationships between buildings and the environment before implementing Passivhaus and green building policies enhances energy efficiency and environmental adaptation. Typically, natural ventilation is inadequate in urban environments. In addition to building layouts, natural indoor ventilation is affected by outdoor street environments. In street and indoor environments with poor ventilation, exhaust gas and pollutants can persist and jeopardize human health and comfort. This paper discusses the effect of building layouts on indoor ventilation performance. The findings indicated that the efficacy of indoor ventilation would be optimized if the direction of the main building layout and that of the main wind lie at an angle of 45 degrees; that the higher the street canyon aspect ratio (H/W) was, the better the efficacy of indoor ventilation was, but compared to the circulation zone in the street it was also higher, and therefore, other related measures or designs should be introduced to solve a lower ventilation efficacy; and that considering different building layouts, the ventilation efficacies of a parallel layout and a intertwined one were similar but led to distinct circulation situations in the street canyon, namely, the parallel layout generating a relatively stable and regulatory circulation however with a marked Venturi effect under a high H/W, and the intertwined one leading to a relatively unstable circulation with a lower Venturi effect.