遮阳系数在透光面积上设遮阳设备时所吸收和透过的太阳热与无遮阳设备时所吸收和透过的太阳热之比
The shading coefficient is the ratio of the solar heat absorbed and transmitted over the light-transmitting area when shading equipment is installed to that when no shading equipment is installed
以上为机器翻译结果，长、整句建议使用 人工翻译 。