British Thermal Unit 59 Degrees Fahrenheit

**Semantic type:** Quantitative Concept

**Definition:** A non-SI unit of energy equal to the amount of heat required to raise the temperature of one pound avoirdupois of air-free water by one degree Fahrenheit (from 58.5 to 59.5 degrees) at a constant pressure of one atmosphere. The British thermal unit at 59 degrees Fahrenheit is based on the definition of the 15 degrees Celsius calorie (exactly 4.1855 joules) and is equal to approximately 1.054804 kJ.

**Synonyms:** - B.T.U. (59F) - B.Th.U. (59F) - BTU (59F) - British Thermal Unit at 59 Degrees Fahrenheit - British thermal unit (59 oF) - British thermal unit at 59 Degrees F - British thermal unit at 59 degrees F - Btu_59 - [Btu_59] - [Btu_59]