U-val·​ue ˈyü-ˌval-(ˌ)yü How to pronounce U-value (audio)
: a measure of the heat transmission through a building part (such as a wall or window) or a given thickness of a material (such as insulation) with lower numbers indicating better insulating properties compare r-value

Word History



First Known Use

1949, in the meaning defined above

Time Traveler
The first known use of U-value was in 1949

Dictionary Entries Near U-value

Cite this Entry

“U-value.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/U-value. Accessed 2 Jun. 2023.

Love words? Need even more definitions?

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