| 摘要: | 隨著世界各國愈趨著重地球資源，建築節能的議題也受到國內外相關單位關注與研析。我國在推動綠建築時，以ENVLOAD指標來檢視其建築外殼耗能。在ENVLOAD公式中，由於日射量變數IHK遠大於溫度差變數DH，因此建築外殼的遮蔽變數M對ENVLOAD的影響力，顯然遠比隔熱變數L來得大，這就是為何外殼遮陽因子遠比隔熱因子重要的原因。然而在現今都市高密度的土地使用下，以往在建築物節能的研究，大多是以單棟建築的思維為出發點，但建築與外部環境的關係是十分密切的，如採光、遮陽、通風會受到鄰棟建築的影響；可是我國在《辦公廳類建築物節約能源設計技術規範》中，對於基地外鄰棟建築物遮蔽之影響，忽略不計。故有失其建築耗能客觀之結果。
本研究係以建築群的思維、及ENVLOAD公式為基礎，進一步針對辦公建築群的外遮陽係數(Ki)加以解析修正。主要以台北地區辦公建築群為例，在模擬的遮蔽影響因子（方位、高度、間距）中，將經由相關之文獻擬訂出假設模型之條件。以下為研究各章節內容之簡要介紹：第一章說明本研究之研究動機、目的、研究內容、方法及研究流程。第二章 主要歸納整理目前各相關領域的研究成果，以及建築節能相關法規的研析。第三章經由ECOTECT電腦模擬操作求得，建築群日射量分佈以了解建築群對熱環境的影響、進而從太陽軌跡圖分析以求得建築外殼在全年中的遮蔽百分比及輻射量。第四章最後由兩個實際案例來實證，分析探討鄰棟建築遮蔽對全年空調用電量密度EUI之影響。第五章本研究期望能藉由可視性之圖表化之結論，提供以建築群的觀點，將鄰棟建築之遮蔽效應納入遮陽係數(Ki)加以考量，提供日後進行進一步管制或修訂ENVLOAD值之參考依據。
經由本研究以『鄰棟遮蔽』觀點探討建築節能效率，最後得出之結論：1.建築群體的數量多寡，會對其整個基地環境場域的熱環境也會有所變動，進而影響到建築外殼耗能的變化。2.透過本研究模擬得到，有受鄰棟建築遮蔽效應的影響其外遮陽係數Ki值大都小於《舊有建築物外殼遮陽節能改善工程設計參考手冊》所規範之基準值Ki≦0.5以下。3.在實例的模擬操作上，不論是南北座向之案例A或是東西座向之案例B，都會因鄰棟建築遮蔽之效應，而使全年空調用電量密度EUI值有所改變。對於日後在計算相關建築節能時，應不可忽視其鄰棟建物之遮蔽效應所帶來的影響。
As the use of the Earth’s resources gains increasing attention from countries around the world, architectural energy-saving issues are being researched by organizations both foreign and domestic. While Green Architecture is being promoted in Taiwan, the ENVLOAD index is being utilized to determine the energy consumption through a building’s outer casing. Since in solation (IHK) is much more important than temperature difference (DH) in the ENVLOAD formula, the influence of the shading variable (M) of a building’s outer casing on ENVLOAD is apparently far more than the heat-insulation variable (L). This is the why the outer-casing shading factor is much more important than the heat-insulation factor. Most former research into the energy-saving properties of buildings has been based on the viewpoint of a single building. Nevertheless, the relationship between buildings and their exterior environments is very closely related in the high-density land use conditions in today’s cities. Factors such as lighting, shading, ventilation etc. will be affected by nearby buildings. Nevertheless, the shading influence from nearby buildings has been ignored in The Technology Standards for Energy-Saving Design for Office Buildings. Therefore the results of building energy consumption research are not objective enough.
This research is based on building-group thought and the ENVLOAD formula to analyze and revise the exterior shading variable (Ki) for an office building group. Most examples are cited from an office building group in the Taipei area. Among simulated shading influence factors (direction, height, distance), the conditions of the assumed model will be determined through related documents. The contents of each chapter in this research are briefly introduced as follows:
Chapter 1 explains the motive, purpose, content, method, procedure of this research.
Chapter 2 mainly introduces 0and arranges the current research results of each related field, and analyzes related laws and regulations regarding building energy savings.
Chapter 3 obtains the distribution of in solation by ECOTECT computer-simulating operation to realize the influence of a building group on a heat environment, then proceeds to acquire the yearly shading percentage and radiation amount for the building outer casing through analysis of the orbital map of the Sun.
Chapter 4 finally demonstrates two real-world cases to analyze and probe the influence of nearby buildings’ shade on the yearly air-conditioning electric consumption density (EUI).
Chapter 5 expects to utilize a visible schematic result to bring nearby buildings’ shading effect into the shading coefficient (Ki) to consider the viewpoint of the building group in order to offer an important reference basis for further control or to revise the ENVLOAD value in the future.
This research inquires into the architectural energy-efficiency of “nearby building’s shading” and finally determines the results as follows:
1. The amount of building group makes the heat environment of whole site environmental field changed and then affects the variation of building’s outer casing energy-consumption.
2. Through simulation, this research determines that the exterior shading coefficient (Ki) influenced by nearby building’s shading effect is mainly less than the basic value (Ki≦0.5) stipulated by The Design Reference Manual for Shading Energy-Saving Improvement for Old Buildings’ Outer Casing.
3. In simulating operation of actual cases, air-conditioning electric consumption density (EUI) varies due to the effect of nearby building’s shading, regardless of the south-north orientation as in Case A or the east-west orientation as in Case B. Therefore, the influence of the shading effect from nearby buildings must not be ignored when computing related architectural energy-savings in future. |
