Window Shading
Window Shading: computes and outputs results from the input parameters.
请输入参数后点击计算
简化模型公式:
投影深度 = P / tan(α)；SC = 1 - min(H, P / tan(α)) / H
其中: P=遮阳板挑出长度, H=窗户高度, α=太阳高度角, K=朝向修正系数（作用于辐射得热估算）
朝向修正系数: 南向 K=1.0, 北向 K=0.3, 东西向 K=0.7
太阳高度角: α = 90 - |纬度 - 太阳赤纬|
本工具为简化模型，实际工程请使用专业软件计算。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Shading coefficient | SC = SHGC ÷ 0.87 (referenced to 3 mm clear glass, SHGC = 0.87) | GB 50189-2015 Design Standard for Energy Efficiency of Public Buildings (annex) |
| Combined SC | SC_total = SC_glass × SC_external shading; external shading has the largest effect | JGJ 75-2012 Design Standard for Energy Efficiency of Residential Buildings in Hot Summer Warm Winter Zone |
| Overhang coefficient | SD = a·PF² + b·PF + c with PF = overhang length ÷ window height (horizontal shading) | JGJ 75-2012 Annex A fitted formula |
| Glass SHGC range | Clear glass 0.85, Low-E IGU 0.35–0.55, coated 0.25–0.45 (varies with coating) | GB 50189-2015 and glass datasheets |
| Energy code limits | South-facing windows SC ≤ 0.35–0.45 in hot-summer/warm-winter zone (by WWR); no limit in severe cold zone | GB 55015-2021 General Code for Building Energy Efficiency and Renewable Energy Utilization |
估算外遮阳构造后的窗户综合遮阳系数，辅助隔热选型与节能判断。