都市日趨高溫化影響下,除了造成室內空調耗能增加、降低戶外熱舒適性,已嚴重影響都市生態問題。其中遮蔽對於戶外熱環境更有顯著影響,戶外遮蔽一方面能直接阻擋太陽輻射量,減少因短波輻射而造成人體的不舒適感受;再則遮蔽所形成陰影能有效降低地面溫度,減少鋪面表面高熱所產生長波輻射量影響。然而植栽、人工建築或構造物等不同戶外遮蔽因子,對於長波及短波反應特性不盡相同,故對於整體之微氣候應有不同影響,亦將反應於抑制熱島效應之效果。在台灣氣候炎熱且面對全球暖化衝擊現況下,亟需探討不同戶外遮蔽因子對於戶外熱環境長期影響,以提供相關戶外遮蔽設計提供參考,達到都市退燒與提升熱舒適性效果。本研究將根據多種遮蔽程度及不同舖面材質選擇多個不同的實測點,並利用相關物理儀器進行戶外長期監測,紀錄空氣溫度(Ta)、相對溼度(RH)、黑球溫度(Tg)、風速(v)等收集平均熱輻射預測模型所需資料,並進行不同鋪面及不同遮蔽程度的比較及熱舒適性的評估與比較,希望提出台灣氣候條件下遮蔽因子對於戶外熱環境的關鍵性影響。
Global warming effects not only increase the energy consumption of indoors but also decrease the thermal comfort in outdoor environment. Shading is the import factors contribute to micro-climate due to the blocking sunlight mitigate the thermal uncomfortable due to of short-wave radiation. Furthermore, the shadows on the ground decrease surface temperature which reduces the long-wave radiation. However, the trees and artificial may cause different effect of thermal comfort which should be further discussed. Since Taiwan have hot and humid weather, its important to offer a guideline for the designer while deal with the microclimate, which help to release the heat island effect and enhance the thermal comfort.