在近年都市逐年升溫的背景下，降溫策略之議題備受關注，其中設置遮蔭是提高人體熱舒適之有效策略之一。然而，回顧熱輻射文獻或評估工具，存在三種潛在問題，一是工具本身不容易使用，二是評估方式無法引導設計，三是評分結果缺乏科學量化數據支持。本研究旨在藉由熱輻射理論的簡化以及各樣評估工具的整合，建立了一個兼具使用性、引導性及科學性效益之基地遮蔭輻射降溫公式，供設計者使用。
在研究方法上，首先於夏日下午進行實測，並透過ISO計算式以及Rayman軟體工具取得Tmrt來驗證ENVI-met模擬值之準確性。同時也簡化了熱輻射理論，基於長短波的輻射接收模式，以人工與自然遮蔭之設計參數創建公式架構，接著依據ENVI-met模擬之Tmrt降溫效益分析來擬訂公式參數，最後試算大量實際案例去進行驗證及適用性評估，並針對該公式進行延伸與補充。
研究成果發現Tmrt之實測與模擬數據於夏日下午時段適配良好，台灣街道常見之1:1寬高比的騎樓在極端高溫之夏季午後可貢獻22℃之Tmrt降溫，若朝西曬方向則會再減少5至8℃，而遮陽板每提升10%透光率約減少3℃之Tmrt降溫效益，且使用木板之降溫效果較混凝土或金屬佳。本研究依上述降溫數據建立各類遮蔭項目的Tmrt降溫效益核對表，於進一步納入面積參數後，研擬出基地遮蔭輻射降溫公式（Site Shading Benefit，SSB），該式可透過簡單運算評估基地戶外空間整體熱輻射接收情形。
研究驗證方面則透過案例的試算，確認SSB公式的使用性、引導性及科學性。此外，本研究亦進一步延伸擴充SSB公式，一是提出評估項目更加完整的詳評版本供設計者參考，二則發展ΔTmrt與ΔPET之間的簡易轉換模式，提出基地遮蔭體感降溫公式SSBthermal，幫助使用者更值觀地瞭解基地遮蔭設計對於基地熱舒適提升的效果。
最後，在應用方面則依據研究成果，提出台灣綠建築評估手冊-社區類（EEWH-EC）戶外遮蔭係數（HIj）的修正建議。並將成果導入臺北熱島降溫指標（HCI）之日射降溫值（Tr）相關計算方式。同時，也基於普通民眾或設計參考者的角度彙整研究成果，將成果精要以條列式的文字建議搭配說明圖例建立遮蔭設計建議指南。

In the context of rising urban temperatures, the efficacy of cooling strategies, particularly shading installations, has garnered significant attention. However, prevalent issues in thermal radiation literature and assessment tools include challenging usability, insufficient guidance for design, and a lack of scientific data support. This study addresses these challenges by simplifying thermal radiation theory and integrating diverse assessment tools. The outcome unveils a site shading radiation cooling formula, a user-friendly, design-guided, and scientifically supported approach for designers evaluating site shading.
The research methodology involves conducting initial measurements on summer afternoons using ISO and Rayman to validate ENVI-met simulation accuracy. This study simplifies thermal radiation theory, creating a formula structure based on short- and long-wave radiation reception modes and translating scientific parameters into actionable design factors. Formula parameters are derived from ENVI-met simulated Tmrt cooling benefits, followed by computations on numerous cases to verify and assess formula applicability.
Findings indicate a good match between the measured and simulated Tmrt data during summer afternoons. A common 1:1 width-to-height ratio colonnade in Taiwan contributes a 22°C cooling effect in extremely hot afternoons, with an additional decrease of 5-8°C if facing west. Each 10% increase in the roof transmittance resulted in an approximately 3°C Tmrt reduction benefit, with wood providing the best cooling effect and metal the least. Based on the obtained cooling data, a Site Shading Benefit (SSB) formula was developed by incorporating area parameters, allowing for a simple calculation to assess the overall radiant heat reception of outdoor spaces on a site.

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