CO_2排放量評估法是現代綠建築體系與建築碳足跡評估最重要的評估工具，其成敗的關鍵在於可靠的系統資材CO_2排放量資料庫及高精度的簡易CO_2排放量應用式。本研究以筆者之前研究所建立300餘項的建築空調 設備CO_2排放量資料庫與22項簡易CO_2排放量推估應用式為核心基礎，實際以42個空調系統工程案例樣本，分別解析空調工程所產生之CO_2排放量，並建立以空調面積或空調裝置容量簡算之CO_2排放量推估公式，其預測精度R2值均在0.9以上。此CO_2排放量推估公式提供了一個十分簡易的空調系統CO_2排放量評估方式，可以在空調設計階段藉由空調面積或空調裝置容量預測可靠的空調系統CO_2排放量，提供建築產業對地球環境衝擊的評估，對綠建築的永續設計與建築碳足跡評估有具體的貢獻。

Assessment of CO_2 emissions is the foremost imperative evaluation tool in modern green buildings and carbon footprints. The key to its success is dependent upon a reliable database system of CO_2 emissions along with an accurate and simple application. This research has been instituted based on more than 300 databases collected from CO_2-emitting air-conditioning units and 22 applications of estimated CO_2 emissions during graduate school. 42 actual air-conditioning system projects are then individually analyzed to derive emitted CO_2. Accuracy of the estimate is backed by coefficient of determination, R2, averaging above 0.9 using volume or capacity of the air-conditioning to formulate CO_2 emissions. It offers a simple assessment method for estimating reliable CO_2 emissions in the design stage by evaluating the impact the construction industry has on the global environment. Sustainable design and assessment of carbon footprint hence has made a significant contribution to green building.