R-value

noun
\ ˈär-ˌval-(ˌ)yü How to pronounce R-value (audio) \

Definition of R-value

: 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

First Known Use of R-value

1948, in the meaning defined above

History and Etymology for R-value

probably from thermal resistance

Keep scrolling for more

Learn More about R-value

Time Traveler for R-value

Time Traveler

The first known use of R-value was in 1948

See more words from the same year

Dictionary Entries near R-value

Ružička

RV

RVA

R-value

RVer

RVSVP

RW

See More Nearby Entries 

Statistics for R-value

Cite this Entry

“R-value.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/R-value. Accessed 25 Jan. 2021.

Comments on R-value

What made you want to look up R-value? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

Test Your Vocabulary

Slippery Words Quiz—Changing with the Times

  • ducreux self portrait yawning
  • What is an earlier meaning of nice?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!