R-value

American  

[ahr-val-yoo] / ˈɑrˌvæl yu /

noun

1. a measure of the resistance of an insulating or building material to heat flow, expressed as R-11, R-20, and so on; the higher the number, the greater the resistance to heat flow.

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Etymology

Origin of R-value

1945–50; R, symbol for resistance

Example Sentences

A higher R-value means the insulation is better at slowing down heat.

From Seattle Times • Dec. 5, 2023

Make sure your pro provides a fact sheet that explains the R-value of your materials.

From Seattle Times • Dec. 5, 2023

Your insulation’s effectiveness is measured in thermal resistance, otherwise known as R-value.

From Seattle Times • Dec. 5, 2023

All three systems would have the same R-value and heat loss or heat gain.

From Seattle Times • Feb. 6, 2023

From an energy-saving perspective, it doesn’t matter, as long as you install the depth recommended on the package to bring the total insulation to the R-value needed where you live.

From Washington Post • Nov. 23, 2021