U-value

[ yoo-val-yoo ]

noun

1. a measure of the flow of heat through an insulating or building material: the lower the U-value, the better the insulating ability.

Word History and Origins

Origin of U-value¹

1945–50; U, symbol for internal energy

Example Sentences

The latest Crittall windows can achieve a U-value - a measure of their insulating performance - as low as 0.8, which is better than standard double-glazed windows.

From BBC

"It's thin and at the same time it has a very good, low U-value," she explains.

From BBC

This captures not only the U-value of the glass but other factors, such as the quality of the frame, which greatly affects the overall performance.

From BBC

Any building material you can think of will have a U-value, a measure of how easily heat passes through the material - the lower the number, the better.

From BBC

Though still to be decided, incoming regulations in England could demand windows have a U-value of 0.8 or below.

From BBC