住宅建築利用熱緩衝空間達成之空調省電及其照明耗電之比較研究-以台大綠房子為例

Abstract

由於能源短缺的問題日益嚴重，近年來在節約建築空調耗能的課題上，「熱緩衝空間(Thermal Buffer Zone)」概念的發展與應用，成為住宅建築有效降低耗能量的設計方式之一。 熱緩衝空間可歸納為外緩衝空間(半室外的陽台、外檐廊及露台)與內緩衝空間(一般住宅中使用時間較短或無裝設冷氣設備需求之室內空間)二大類型，住宅建築透過熱緩衝空間的配置設計，發揮其遮陽與隔熱之功能，可以達到調節室內熱環境、節約空調耗電量之效果。但是，從室內晝光利用層面而言，熱緩衝空間卻也可能因遮蔽窗口部採光量，反使室內在白天需要多開燈具而增加照明耗電。是故探討熱緩衝空間於住宅建築之應用方式，並量化比較其對冷氣耗電及日間照明耗電量之影響與增減比例，成為本研究欲解決之主要課題。 本文從彙整前人於熱緩衝空間應用對空調耗能量影響之相關實證研究開始，擷取其研究思路、方法、工具的應用以及變因的設定方式；而後以台灣大學內之節能示範屋-綠房子為實例，在經過電腦數值模擬工具計算結果的準確性驗證後，分別針對綠房子空間配置實況與剔除外緩衝空間(陽台、外檐廊及露台)、內緩衝空間(陽光室及儲藏室)，建置了不同空間配置方式之綠房子建築數值模型，並進行了全年逐時冷氣耗電及日間照明耗電量之數值模擬計算與結果之比較分析。 研究結果顯示，在綠房子原有空間配置型態下，全年冷氣耗電量經計算為3383.69Kwh，日間照明耗電量為1473.78 Kwh，總計為4857.47Kwh。為了得知綠房子在完全無熱緩衝空間可供遮陽、隔熱，但卻不影響窗口部採光之情況下，各項耗電量之增減比例，故於數值模型中剔除室外的陽台、露台、外檐廊空間以及室內的陽光室與儲藏室後，得到的計算結果為全年冷氣耗電量大幅增加為6471.02 Kwh，而日間照明耗電量僅略減少為1289.91Kwh，總耗電量為7760.93 Kwh，較原先增加了59.77％。 在台灣熱濕氣候型態下，住宅建築適當應用熱緩衝空間減緩室外熱源向室內空調空間之傳遞，具有相當可觀之空調節能效益。以本研究案例而言，若在最初設計時未考慮熱緩衝空間之利用，住宅建築冷氣耗電量將大幅度提升，而日間照明耗電量則僅小幅降低，是故熱緩衝空間之運用確實具有積極正面之節能效益，為未來我國住宅建築節能設計上可採行之有效策略。

As energy shortage is more and more serious, in recent years, the development and application of thermal buffer zone in saving air conditioning energy consumption becomes a design which can effectively reduce energy consumption of residential architecture. The thermal buffer zone can be classified into exterior buffer zone (Semi-outdoor veranda, eaves gallery and balcony) and interior buffer zone (Indoor zone of common residence which only uses air conditioning equipment for a short time or needs no conditioning equipment). The application of thermal buffer zone in residential architecture for sunshade and heat insulation purpose has the effect of adjusting indoor heat environment and saving air conditioning energy consumption. However, as for indoor utilization of day lighting, because thermal buffer zone decreases the amount of available sunlight at the window, the lighting energy consumption will increase as more lamps and lanterns are required. Therefore, this research tries to discuss the application method of thermal buffer zone in residential architecture and make quantitative comparison of its influence on air conditioning energy consumption and daytime lighting energy consumption, as well as the increase and decrease proportion. This essay first summarizes the predecessors’ empirical researches studying the influence of thermal buffer zone on air conditioning energy consumption, in order to capture their research approaches, methods, tools, and variable setting methods. Then, taking the N.T.U energy-saving demonstration room—Smart Home as an example, this research establishes green house construction numerical models in light of different spatial allocations respectively ignoring external butter zone (veranda, eaves gallery and balcony) and internal butter zone (sunny room and store room) after validating the accuracy of computer numerical simulation calculating result. In addition, this research compares and analyzes the numerical simulation calculating result of air conditioning energy consumption and daytime lighting energy consumption in all-year times. The result shows that with the original spatial allocation, the green house will consume 3383.69Kwh energy by air conditioning system all the year around and 1743.78Kwh by daytime lighting, so totally the energy consumption is 4857.47Kwh. To get the increase and decrease proportion of energy consumption when no thermal buffer zone is applied in the green house for sunshade and heat insulation purpose, and consequently the amount of available sunlight at the window will not be influenced, this research respectively removes the outdoor veranda, eaves gallery and balcony and indoor sunny room and store room from the numerical model. The result shows that the air conditioning energy consumption all the year around will increase steeply by 6471.02 Kwh, and the daytime lighting energy consumption all the year around will only decrease a little by 1289.91Kwh, so the total energy consumption is 7760.93 Kwh, 59.77% more than before. In the hot and humid climate of Taiwan, appropriate application of thermal buffer zone in residential architecture to reduce heat transfer from outdoors to air conditioning zone can produce a considerable energy saving effect in air conditioning system. According to this case study, if no thermal buffer zone is applied in the design of residential architecture, the air conditioning energy consumption will increase steeply and the daytime lighting energy consumption will only decrease a little, so the application of thermal buffer zone really has a positive effect in energy saving and is an feasible and effective strategy for the future energy saving design of residential architecture.