R-value
noun
: a measure of resistance to the flow of heat through a given thickness of a material (such as insulation) with higher numbers indicating better insulating properties compare u-value
Examples of R-value in a Sentence
Recent Examples on the Web
Look for a sleeping pad with an R-value of five or higher.
—
Kaelyn Lynch,
Outside,
23 Jan. 2026
Pick insulation with the right R-value for your climate; fiberglass is the easiest and most affordable choice.
—
Timothy Dale,
The Spruce,
17 Jan. 2026
Insulation is identified and labeled by R-value.
—
Sarah Moore,
Freep.com,
12 Dec. 2025
Most experts agree the R-value of attic insulation should be at least R-30 (R-38 is preferable in northern climates).
—
Chad Murphy,
The Enquirer,
2 July 2025
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Kaelyn Lynch,
Outside,
23 Jan. 2026
Pick insulation with the right R-value for your climate; fiberglass is the easiest and most affordable choice.
—
Timothy Dale,
The Spruce,
17 Jan. 2026
Insulation is identified and labeled by R-value.
—
Sarah Moore,
Freep.com,
12 Dec. 2025
Most experts agree the R-value of attic insulation should be at least R-30 (R-38 is preferable in northern climates).
—
Chad Murphy,
The Enquirer,
2 July 2025
Cite this Entry
“R-value.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/R-value. Accessed 5 Jul. 2026.
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