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(ˈyuˌvæl yu)

a measure of the flow of heat through an insulating or building material: the lower the U-value, the better the insulating ability. Compare R-value.
[1945–50; U, symbol for internal energy]
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References in periodicals archive ?
A U-value is a numerical measurement of the amount of heat lost through a specific material.
To meet the environmental criteria, panels are injected with CFC-free polyurethane foam providing a thermal efficiency U-value of 1.
U-value is a measure of uncertainty first reported in a paper on the analysis of serial dependencies in response chains by Miller and Frick (1949).
At the same time, depending on tape width, it will also supply a U-Value as low as 0.
Results show the critical aspects of 100% WWR buildings: in the coldest climate the main problem is the huge surface of relatively high glass U-value compared with standard walls, while in the warmer one the main efforts need to be done to avoid the summer overheating caused by incoming solar radiation.
He said that the current college curriculum "quite rightly" covered the basic roofing installation essentials - but failed when it came to incorporating "crucial" energy efficient-related skill sets, such as U-value calculations, condensation risk analysis and heat-loss monthly savings.
Our thermal door, for example, is tested, and we can provide an accurate U-value to prove its efficiency.
We have exceeded those standards on many, many counts -- from the U-Value, to the thermal insulation, through to the performance of the HVAC system.
Energy efficiency is also a key priority: an exceptional U-value of 1.
Properties built post-1994 must achieve a minimum U-value (ie the rate at which heat passes through a wall/roof/window etc).