British thermal unit

British thermal unit, abbr. Btu, unit for measuring heat quantity in the customary system of English units of measurement, equal to the amount of heat required to raise the temperature of one pound of water at its maximum density [which occurs at a temperature of 39.1 degrees Fahrenheit (°F) ] by 1°F. The Btu may also be defined for the temperature difference between 59°F and 60°F. One Btu is approximately equivalent to the following: 251.9 calories; 778.26 foot-pounds; 1055 joules; 107.5 kilogram-meters; 0.0002928 kilowatt-hours. A pound (0.454 kilogram) of good coal when burned should yield 14,000 to 15,000 Btu; a pound of gasoline or other fuel oil, approximately 19,000 Btu.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on British thermal unit from Fact Monster:

  • Conversion Factors - Conversion Factors Below are instructions for converting factors, including changing acres to ...
  • Btu - Btu: Btu: see British thermal unit.
  • Miscellaneous Units of Measure - Miscellaneous Units of Measure Below is information about units of measure, including acre, bolt, ...
  • thermal unit - thermal unit: thermal unit: see British thermal unit.
  • Top Energy Producers and Consumers - Top Energy Producers and Consumers The United States produces the most energy in the world, but it ...

See more Encyclopedia articles on: Physics