Radiant Heat through Windows

Solar heat gain with roller shades, vertical blinds and Venetian blinds

Sun Radiation through Windows

Heat gain from sun radiation through windows can be controlled with shades and blinds.

Type of Shading

Transmitted Solar Energy
(%)
Reflected Solar Energy
(%)
Absorbed Solar Energy
(%)
Single or double glass without shading 75 - 80 10 - 20 10 - 20
Vertical Blinds 5 40 - 60 35 - 55
Venetian Blinds 0 23 77
Roller Shades < 25 15 - 80 20 - 65

Effect of Shading compared with unshaded Window

Types of Shading Fraction of Gain through Unshaded Window
Unshaded Window 1.00
Inside roller shade - half-drawn 0.80
Inside roller shade - fully-drawn 0.62
Inside venetian blind 0.65
Canvas awning 0.30
Outside shading screen - solar altitude 20o 0.38
Outside shading screen - solar altitude 30o 0.25
Outside shading screen - solar altitude 40o 0.18

Search the Engineering ToolBox

Engineering ToolBox - SketchUp Edition - Online 3D modeling!

3D Engineering ToolBox - draw and model technical applications

Engineering ToolBox - SketchUp Edition - enabled for use with the amazing, fun and free Google SketchUp

Translate the Engineering ToolBox
About the EngineeringToolbox