應用全尺度實驗屋探討植栽牆熱性能之研究

Abstract

台灣自產能源缺乏，一間設計良好的建物可以有效減少日常耗能，而日常使用所消耗的能源遠高於營建所需之耗能。夏日空調用電占總用電約40%，因此若建物設計良好藉由減少冷氣使用而有效減少建物之耗能。建物立體綠化是建物完成過後有效節省空調耗能的手段之一，建物立體綠化包含綠屋頂與植栽牆。近年來綠屋頂與植栽牆系統皆有許多研究：在植栽牆實驗方面針對季節、天氣、日夜、覆蓋率探討在熱溼氣候中的研究較少被提及；植栽牆模擬研究方面，大多研究經由許多假設及簡化將植栽牆轉至為其他物件。對此本研究目的是藉由全尺度實驗屋裝設以常綠植物組成的植栽牆，進行不同季節、天氣、覆蓋率、日夜為變因的實驗；並針對建立植栽牆基於能量及水量平衡建立物理模型再以全尺度實驗屋驗證。在實驗觀察結果上，日間使用之建物，在夏季可以增加27%左右的熱舒適滿意度，而冬季卻會降低5%左右的熱舒適滿意度，因此若採用落葉植物可能會有較佳的效益。至於夜間使用的建物，熱舒適滿意度的影響均在5%以下，不論增加或降低，故若有經費因素考量，可不必裝設植栽牆。在模擬驗證上，植栽層表面溫度模擬結果表現最佳，標準化方均根誤差為7.3%；含水率表現結果最差標準化方均根誤差為19.8%。

A shortage of domestic energy production has always been a concern in Taiwan. A well-designed building may effectively alleviate this problem for the daily use of a building outcompetes all other aspects in energy consumption such as construction. Statistics has shown that about 40% of energy consumption in summer can be attributed to air conditioning. Therefore, it is very likely to reduce the total energy consumption if a building is well-designed for humans and the air conditioning can be less frequently operated. Building greenery, including green roofs and green walls, is one of the most effective ways to save energy from the excess use of air conditioning. Most of the recent studies focus on green roofs and green walls. However, of the green-wall studies, few experiment mentioned the effects from seasons, weather, day-and-night and coverage. Additionally, oversimplification of parameters by certain assumptions has usually been made in the studies of green-wall simulation. To assess the effects of environmental factors and coverage on green walls, a full scale study house is set with an evergreen plant (Asparagus sprengeri)-covered green wall for experiments; to build the model with physical based energy and water balance and validate it.. The results show a 27% increase of the Predicted Percentage of Dissatisfied in summer but a 5% decrease in winter in the house with the green wall used in day time. As a result, if the green walls adopt deciduous plants rather than the evergreens, the benefits of thermal comfort could be better. For the buildings used in night time, green walls show only about 5% increase or decrease of the Predicted Percentage of Dissatisfied, implying that, if there is short of funding, it is not necessary to set green wall for these buildings. The results of simulation show that the surface temperatures of foliage layer is the paremeter most close to the experiments, with the normalized root-mean-square error (NRMSE) only 7.3%; water content simulated is the most deviant, with the NRMSE up to 19.8%.