本法是以“达尼留克图表”为基础，用简单的计算方法求取投光口的基本光束量。实践表明本法有助于设计人员较好地掌握计算精度、节约时间。 根据“立体角投影定律”的概念，将立体角ω分解为δ和η，分别代表窗洞高度ａ及宽度ｂ与幅射距离ｒ的比值。算出δ和η，立即可换算成ｅ１和ｅ２，那么ｅ１×ｅ２×ｃｏｓθ即窗洞的基本光束量。 考虑到投射角度的变化和墙厚的影响，按下列公式计算δ和η： １．对垂直安装的窗： δ＝（ａｓｉｎθ-ｔｃｏｓθ）ｃｏｓθ／ｈ　　① η＝（ｂｓｉｎβ-ｔｃｏｓβ）ｃｏｓθ／ｈ　　② ２．对水平安装的窗： δ＝（ａｃｏｓθ-ｔｓｉｎθ）ｃｏｓθ／ｈ　　③　 η＝（ａｓｉｎβ-ｔｃｏｓβ）ｃｏｓθ／ｈ　　　 ３．对大厅式多 窗（垂直安装）： δ＝（ａｃｏｓθ-ｔｃｏｓθ）ｃｏｓθ／ｈ　　 η＝Ｎ（ｂｓｉｎβ-ｔｃｏｓβ）ｃｏｓθ／ｈ　④ ４．对任意倾角安装的窗先用“外切角换面法”换成水平窗，再用③式和②式求得δ、η。 式中：ｈ——窗中点至工作面的高度（Ｍ） Ｎ——多樘窗的樘数。 ｂ——多樘窗的平均宽（Ｍ） ｔ——墙厚（Ｍ） θ——垂直投射倾角， β——水平投射倾角。 算得δ和η成换成ｅ１ｅ２后，按下式计算出采光系数Ｃ。 Ｃ＝ｅ１×ｅ２ This method is based on the “Danieluk chart” and uses a simple calculation method to obtain the basic beam quantity of the light projection port. Practice shows that this method helps designers to master the calculation accuracy and save time. According to the concept of “solid angle projection law”, the solid angle ω is decomposed into δ and η, which respectively represent the ratio of window height a and width b to the radiation distance r. Calculate δ and η and immediately convert it into e1 and e2. Then e1×e2×cosθ is the basic beam amount of the window hole. Taking into account the change in projection angle and the effect of wall thickness, calculate δ and η as follows: 1. For vertically mounted windows: δ=(asinθ-tcosθ)cosθ/h 1 η=(bsinβ-tcosβ)cosθ/h 2 2. For horizontally mounted windows: δ=(acosθ-tsinθ)cosθ/h 3 η=(asinβ-tcosβ)cosθ/h 3. For hall type multi-window (vertical installation): δ=(acosθ-tcosθ)cosθ/h η=N(bsinβ-tcosβ)cosθ/h 4 4. For windows with arbitrary inclination angles, use the “external angle change surface method” to replace the horizontal window, and then use δ and η to obtain δ and η. Where: h - the height of the window from the midpoint to the work surface (M) N - the number of turns in the multi-window. b - Average width of the multi-sacral window (M) t - Wall thickness (M) θ - Vertical projection inclination, β - Horizontal projection inclination. After calculating δ and η to be replaced by e1e2, the lighting factor C is calculated by the following equation. C=e1×e2