: 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
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Products like these provide, in most cases, par and above par R-values for the contractor, and that truly depends on the application on the project. Don Magruder, The Tennessean, 22 Sep. 2024 The walls have a thermal resistance or R-value of 80, so the homeowner benefits from energy savings on top of cost savings. Jennifer Castenson, Forbes, 15 Dec. 2024 The Tensor All-Season has an R-value of 5.4 and weighs just 18.2 ounces. Scott Gilbertson, WIRED, 29 Nov. 2024 Pairing your sleeping bag with a sleeping pad that has sufficient insulation (measured as the R-value) is essential to getting the maximum warmth and performance from a bag. Kevin Brouillard, Travel + Leisure, 4 Nov. 2024 And, with an R-value of 7.0 (which is a measurement of the pad’s insulation to protect you from the cold ground below), this pad offers adequate warmth for year-round camping. Kevin Brouillard, Travel + Leisure, 25 Sep. 2024 Its thickened exterior walls, triple-glazed windows, and minimal heating system give it an impressive R-value of over 40, significantly boosting energy efficiency. New Atlas, 18 Sep. 2024 Though pricey, this super-warm pad from NEMO gives winter campers a good night’s sleep with a toasty 8.5 R-value, one of the best in its class. Emily Pennington, Condé Nast Traveler, 13 Nov. 2023 This insulation provides the highest R-value per inch of thickness, ensuring significantly lower heating and cooling costs. Chris Gallagher, USA TODAY, 16 Jan. 2024

Word History

Etymology

probably from thermal resistance

First Known Use

1948, in the meaning defined above

Time Traveler
The first known use of R-value was in 1948

Dictionary Entries Near R-value

Cite this Entry

“R-value.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/R-value. Accessed 22 Jan. 2025.

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