| 摘要: | 「外遮陽」可隔絕日照，能改善室內溫熱環境，是建築基本設計中極為重要的節能手法。因此本研究目的探討施作水平式外遮陽對於建築物室內溫熱環境、舒適度、不滿意度、及節能效益的影響。本研究調查場址為嘉南藥理大學校園內B棟大樓窗口朝南的三樓(B305)及四樓(B406)的教室。調查分為兩階段進行，第一階段期間(民國103年10月~民國104年2月)，B305教室已完成水平室外遮陽施作(深度比為0.8)，而B406教室則無施作外遮陽，此階段之研究目的為探討施作水平式外遮陽對室內溫度的影響；第二階段期間(民國104年3月~民國104年5月)，B406教室也施作了水平室外遮陽，惟設計了不同的深度比(0.9)，此階段探討不同深度比對水平式外遮陽之隔熱效果的影響。本研究主要量測室內的三維空間溫度，以更能詳細解析室內溫度的空間分布；日時間動態調查則分三個時段，上午時段(8:00~9:00)、中午時段(11:00~12:00)、下午時段(14:00~15:00)，以觀察不同時段的室溫變化。同時，也量測室內溼度，以評估室內環境的舒適度(Predicted Mean Vote，PMV)及不滿意度Predicted of Percentage Dissatisfied)，PPD)指標。第一階段期間計量測22天次，實驗結果顯示B305教室的中央剖面平均溫度低於B406教室，尤其中午時段差異最大，中央縱剖面平均溫度B305較B406教室低1.5℃~1.6℃，中央橫剖面平均溫度B305低於B406教室1.6℃。中午時段，B305教室在高度200cm處的水平剖面平均溫度，可低於室外溫度達2.8℃。教室靠窗戶與靠走廊的平均溫差，B305教室為0.1~0.5℃，明顯低於B406教室的0.3~1.0℃。以上監測結果可說明水平式外遮陽的隔熱效果。B305教室的舒適度(PMV)平均值0.14優於B406教室的0.37，而不滿意度(PPD)平均值B305教室為10%亦低於B406教室的14%。在第二階段共進行11天次實驗，B406施作水平式外遮陽後室溫轉變成與B305接近且差異不大，中午時段的中央縱剖面平均溫度B305僅低於B406教室0.1℃~0.2℃，中央橫剖面平均溫度B305低於B406教室0.1~0.2℃。中午時段，B406教室在高度200cm處的水平剖面平均溫度，B406教室與室外溫度相差2.7℃，而B305教室與室外溫度相差2.5℃。教室靠窗戶與靠走廊的平均溫差，B305教室為0.1~0.4℃，B406教室為0.1~0.3℃。B305教室與B406教室的舒適度(PMV)平均值均為0.80，而不滿意度(PPD)平均值B305教室為28%，B406教室為27%。本研究另外以實測溫度代入熱傳導公式推估室內外熱傳送通量，並且以冷氣冷房防能力與耗電量推估出節能與減碳效益。結果顯示，有施作水平室外遮陽的教室，一年約可節省電量為156 kw-hr/yr，相當於節省343元/yr的電費及減少225.83 kg C/yr的二氧化碳排放量。水平式外遮陽處於模擬性實驗，而沒實際長時間監測，透過本實驗研究更可瞭解，探討施作前與施作後對於室內溫熱環境影響，以利往後施作水平式外遮陽參考之依準，提升水平式外遮陽之效益。
External shading is an important energy-saving method in architecture which can isolate sunlight as well as alter indoor thermal environment. Therefore, this study is to investigate the effects of building facilities for horizontal exterior shading on indoor thermal environment, comfort, dissatisfaction, and energy saving.The investigated sites of this study were classrooms of the campus buildings B with south-facing window at Chia Nan University of Pharmacy and Science, on the third floor (Class B305) and the fourth floor (Class B406). There are two stages in the surveys, during the first stage (Oct., 2014 to Feb., 2015), class B305 was equipped with external shading (depth ratio at 0.8), while the class B406 was not. The study purpose of this stage is to investigate the effect of horizontal exterior shading on room temperature. During the second stage (March, 2015 - May, 2015), class B406 was also applied external shading, but in depth ratio at 0.9, in order to discuss the effect of different depth ratio on horizontal external shading. This study measured three-dimensional space of indoor temperature, in order to analyze the profile of the indoor temperature. Three periods has been experimented, morning session (8:00~9:00), at noon time (11:00~12:00), and afternoon session (14:00~15:00), to observe changes in room temperature in different periods. Besides, the indoor humidity, the comfort of the indoor environment (Predicted Mean Vote, PMV) and dissatisfaction Predicted of Percentage Dissatisfied), PPD) index have as well as been experimented.During the first stage, 22 monitoring days have been conducted, results showed that the average temperature of the central cross section in class B305 was less than B406, especially at noon time. The average temperature of the central longitudinal section of the class B305 was 1.5~1.6 ℃ lower than B406. The average cross-sectional temperature in class B305 is about 1.6℃ lower than class B406. At noon time, horizontal section at the height of 200 cm in class B305 can be lower than the outdoor temperature of 2.8 ℃. The average temperature difference between the window side and the aisle side showed 0.1 ~ 0.5℃in class B305, which was significantly lower than 0.3 ~ 1.0℃in class B406. These results illustrated the effect of horizontal insulation of external shading. PMV in class B305 was 0.14 better than 0.37 in class B406, while the index of PPD was 10% in class B305 lower than 14% in class B406.A total of 11 monitoring days was experimented in the second stage. After class B406 being equipped with horizontal external shading, the temperature converted to be close to the temperature in B305. At noon, the figure of central longitudinal sectional and central cross section in class B305 were 0.1 ℃ ~ 0.2 ℃ lower than class B406. At noon, at the 200 cm height, class B406 compared to outdoor temperature difference was 2.7 ℃, while class B305 compared to outdoor temperature difference was 2.5 ℃. Results of temperature difference between window side and aisle side, 0.1 ~ 0.4 ℃ in class B305, 0.1 ~ 0.3 ℃ in B406. Both PMV in class B305 and class B406 were 0.80, while dissatisfaction (PPD) in class B305 was 28%, 27% in B406.In this study, measured-temperature was brought into heat transfer equation to estimate the flux of heat transfer from indoor to outdoor. Results showed that class with external shading can save 156 kw-hr/yr of electricity, which was 343 NT dollars per year and can reduce 225.83 kg C/yr of carbon dioxide.Horizontal external shading was in the simulation experiment, and not the long time monitoring. Through this study, better understandings were offered to the thermal changes of applying external shading for future standard to enhance efficiency of horizontal external shading. |
