建築溫室氣體排放量預估及減量策略分析─以商辦建築為例

Abstract

在國內溫室氣體減量及管理法通過後，規範各部會需針對未來可能的溫室氣體排放量進行管制及減量，而本研究之目的為探討在國內人口及經濟發展之情況下，並考慮未來氣候變遷之條件，商辦建築溫室氣體排放量的變化，以及在改善商辦建築外殼隔熱性能之策略下，其帶來之效益，供住商部門參考。 本研究採用由下而上之模擬方式，依照商辦建築之使用情形建立耗能模擬模型，模型包含空調、照明及事務設備之推估公式。在空調耗能模擬方面利用蒙地卡羅設計法及拉丁超立方抽樣設計1000個商辦建築案例，其參數包括外殼性能、空調設備、室內條件等，並將模型代入EnergyPlus進行模擬，氣象條件則採用標準氣象年與全球大氣環流模式所產製的未來逐時氣象年，藉以模擬未來空調耗能密度之分布，照明及事務設備則參考過去文獻設定其使用密度以及運轉時間以推求其耗能密度之分布，接著利用未來商辦之樓地板面積，即可求得未來商辦建築之空調、照明及事務設備之耗能。由於其餘設備之占比較少，因此擬採用比例推估之方式計算。 推估結果顯示，由於未來的氣溫將微幅上升，以及經濟發展之情況下，未來2035年之商辦建築總耗電量將比2000年上升31.3%，溫室氣體排放量參考溫管法以2005年為基準年，若發電結構維持現況，2025年之排放量可能增加10.4%；若未來發電結構改變，參考能源局公告之電力碳排係數推估，2025年之排放量預計減少18.3%。 本研究之商辦建築溫室氣體減量策略將改善建築外殼中的外牆U值與窗玻璃之日射透過率 (SHGC)，並從原有的1000個案例中挑出外殼性能較差的案例進行改善，採EnergyPlus模擬的方式探討其改善計畫帶來之效益，結果顯示改善策略執行完畢時可為該年帶來3%的減量效益。

After the Greenhouse Gas Reduction and Management Act passed in Taiwan, it stipulates that government agencies have to establish strategies to reduce and manage greenhouse gas (GHG) emissions. The purpose of this study is to predict nationwide GHG emissions in commercial office buildings considering population growth, economic development and climate change in future and the benefits of the reduction strategies of improving the thermal performance of the building envelope. This study developed a bottom-up simulation model based on the occupants’ behavior, including the energy consumption of cooling, lighting and equipment. In terms of cooling energy consumption simulation, 1000 cases were generated using Monte Carlo simulation and Latin hypercube sampling method. The parameters of cases include building envelope, HVAC systems, internal heat gains, etc. Then, annual cooling energy use intensity (EUI) can be obtained by using EnergyPlus to simulate these cases with future hourly weather data produced by morphing method which uses the changes in future weather monthly averages to stretch, shift, or stretch and shift existing TMY files. Regarding the annual lighting and equipment energy use intensity, it can be calculated by power level per floor area and operation schedule. Next, the future commercial office building energy consumption can be calculated by EUI and building floor area, and the other energy consumption will be estimated according to its proportion because it is not very significant. The results show that the energy consumption of the commercial office buildings of 2035 was 31.1% up on that of 2000 because of increasing temperature and economic development. In terms of GHG emissions, if the composition of electricity source is maintained, the emissions of 2025 may increase by 10.4%; if changed with the energy policy, the emissions of 2025 may decrease by 18.3%, compared to 2005. The GHG reduction strategies in this study will focus on improving U-value of exterior walls and solar heat gain coefficient (SHGC) of windows’ glass. Worse cases will be selected from original 1000 cases with U-value and SHGC and improved. The benefits of the strategies will be simulated by EnergyPlus. When all worse cases were improved, the GHG emissions can decrease by 3%, compared to business-as-usual scenario.