不同氣候下建築外殼隔熱性能對空調冷房負荷量影響之研究

Abstract

熱傳透率（U值）是影響建築能源消耗的重要指標，U值越低表示熱阻效果越佳，能有效降低冷暖房負荷，因此各國建築法規持續調降最大允許U值，以提升能源效率。然而，部分研究指出，U值並非越低越好，不同氣候條件下存在使建築能耗達到最低的最佳U值，當U值低於該最佳值時，反而會導致能耗上升，稱為「隔熱反效果現象」，此現象多發生於亞熱帶、熱帶及地中海型氣候區，因為高隔熱設計在降低外部熱入的同時，也限制室內熱量散出，並增加建材成本與空調耗能。本研究使用EnergyPlus模擬東亞八個地點辦公與住宅建築之能源負荷量，探討不同氣候條件下U值與冷暖房負荷之關係，以及隔熱反效果發生的區域，並提供建築法規最大允許U值的參考依據。

Thermal transmittance (U-value) is a crucial indicator influencing building energy consumption, where lower values indicate better thermal resistance and can effectively reduce heating and cooling loads. Accordingly, building codes worldwide have progressively lowered the maximum allowable U-values to improve energy efficiency. However, some studies indicate that lower U-values are not always better. There exists an optimal U-value under various climatic conditions that minimizes building energy use. When the U-value drops below this optimal point, energy consumption may increase—a phenomenon known as the "anti-insulation effect." This effect frequently occurs in subtropical, tropical, and Mediterranean climates, where high insulation reduces external heat gains but also hinders indoor heat dissipation, leading to increased air conditioning loads and construction costs. This study employs EnergyPlus to simulate the energy loads of office and residential buildings across eight locations in East Asia, investigating the relationship between U-values and total loads under varied climate conditions, identifying regions susceptible to the anti-insulation effect, and providing references for setting maximum allowable U-values in building regulations.