How to read a window label

Window labels contain wealth of knowledge about energy efficiency and performance of the window. The most important label to look at is National Fenestration Rating Council – an independent window and door third party rating organization. Replacement window cost ct

window label

A – U-Factor also known as U-Value describes the amount of heat flow and usually falls between 0.15 and 1.20. The lower the number is the better the window is at resisting heat escaping from your house during winter. This number is considered among professionals to be the most important factor of window performance.
B– Solar Heat Gain Coefficient also known as SHGC for short determines the how much long-wave ultraviolet radiation is admitted trough your window. Replacement window cost ct Again the lower the number the better the window is at keeping heat out during the summer. Usually it falls between 0 and 1.
C– Visible Transmittance is the amount of sunlight (daylight) is passing through your windows. The higher the number the more light is admitted to your home. Normally the number can be anywhere between 0 and 1.

SHGC