Window Terminology: Window Terms Starting with "U"

U-Factor (U-value)

Measures heat loss or heat gain through a product.  The U-factor may be expressed for the glass alone or the entire window, which includes the effect of the frame and the spacer materials. The lower the U-factor, the greater a window's resistance to heat flow and the better its insulating value.

Ultraviolet Light (UV)

The invisible rays of the spectrum that are outside of the visible spectrum at its short-wavelength violet end. Ultraviolet rays are found in everyday sunlight and can cause fading of paint finishes, carpets, and fabrics.


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Universal Windows Direct

Nationwide group of dealers and window installers that offer the exclusive UniShield line of windows, siding and doors at factory direct prices.


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