鋼筋混凝土外牆降低熱傳改善方式之研究－以台灣鄉村地區農宅為例

Abstract

台灣鄉村地區農宅普遍為獨棟興建的建築，使外牆易直接受到日照的影響，又這些農宅的外牆多以12cm鋼筋混凝土構造為主，再以水泥砂漿粉刷，其隔熱性能不佳，造成夏日室內過熱的問題，因此本研究將以既有的外牆為基礎，從設計面上提出降低熱傳改善方式，並對各改善方式中不同的模組進行隔熱性能、厚度與經濟性評估。 透過理論與實際面的了解，歸納出以下6種外牆降低熱傳改善方式，分別為：室內增設隔熱層、室內增設封閉空氣間層、室外增設隔熱層、外牆表面噴抹塗料、室外增設封閉空氣間層、室外增設流動空氣間層。 研究結果顯示，室內增設隔熱層改善方式與室內增設封閉空氣間層改善方式的熱得減少率約在60%~80%之間；室外增設隔熱層改善方式的熱得減少率約在70%~90%之間；外牆表面噴抹塗料改善方式的熱得減少率在37%~55%之間；室外增設封閉空氣間層改善方式的熱得減少率在41%~51%之間；室外增設流動空氣間層改善方式的熱得減少率在53%~62%之間。 在30%~50%熱得減少率時，外牆表面噴抹塗料改善方式的不同模組中，有最理想厚度之模組與最理想價格之模組；在60%熱得減少率時，室內增設隔熱層改善方式的不同模組中，有最理想厚度之模組，而室內增設封閉空氣間層改善方式的不同模組中，有最理想價格之模組；在70%熱得減少率時，室外增設隔熱層改善方式的不同模組中，有最理想厚度之模組，而室內增設隔熱層改善方式的不同模組中，有最理想價格之模組；在80%~90%熱得減少率時，室外增設隔熱層改善方式的不同模組中，有最理想厚度之模組與最理想價格之模組。

Residential buildings in rural areas of Taiwan are typically large detached houses, which are exposed to direct sunlight on their exterior walls as there are no surrounding buildings to block sunlight and create shade. Also the 12cm reinforced concrete exterior walls are the mainstream in Taiwan’s residential buildings, which has the property of high thermal conductivity that can easily make the thermal flow transfer indoors. So this research is under the premise of retaining the original exterior walls, from the design point of view to develop the methods of reducing heat transmission, and make on assessment of each model’s performance, thickness and economic viability. Through the understanding of theory and practical perspectives, the methods of reducing heat transmission from the exterior walls can be summed up as follows six methods: additional interior insulation layers, additional interior closed cavities, additional exterior insulation layers, outer surface painting, additional exterior closed cavities and additional exterior naturally ventilated cavities. The results showed that the additional interior insulation layers method and the additional interior closed cavities method could reduce the indoor heat gain by about 60%-80%; the additional exterior insulation layers method could reduce the indoor heat gain by about 70%-90%; the outer surface painting method could reduce the indoor heat gain by between 37% and 55%; the additional exterior closed cavities method can reduce the indoor heat gain by between 41% and 51%; and the additional exterior naturally ventilated cavities method could reduce the indoor heat gain by between 53% and 62%. When the purpose is to reduce the indoor heat gain by about 30%-50%, the outer surface painting method consists of the optimal models from the thickness point of view and the economy point of view; when the purpose is to reduce the indoor heat gain by about 60%, the additional interior insulation layers method consists of the optimal model from the thickness point of view and the additional interior closed cavities method consists of the optimal model from the economy point of view; when the purpose is to reduce the indoor heat gain by about 70%, the additional exterior insulation layers method consists of the optimal model from the thickness point of view and the additional interior insulation layers method consists of the optimal model from the economy point of view; when the purpose is to reduce the indoor heat gain by about 80%-90%, the additional exterior insulation layers method consists of the optimal models from the thickness point of view and the economy point of view.