Definition

1. Noun:
   • A unit of heat measurement: The British thermal unit is a traditional unit of energy. It is defined as the amount of heat energy required to raise the temperature of one pound of water by one degree Fahrenheit at a specified condition (one atmosphere of pressure).

Usage

• The British thermal unit is primarily used in the United States and, to a lesser extent, the United Kingdom, to quantify energy content, particularly for fuels (like natural gas), heating, and cooling systems. It is a common unit in the power, steam generation, and air conditioning industries.
• It is often abbreviated as Btu (or BTU).

Examples

• Noun:
  • This air conditioner has a cooling capacity of 12,000 British thermal units per hour.
  • Natural gas is typically sold by the thousand cubic feet, with its energy content measured in British thermal units.
  • One British thermal unit is approximately equal to 1,055 joules.

Advanced Usage

• "Btu/hour (Btu/h)": A common unit of power, indicating the rate of energy transfer per hour. This is frequently used to specify the output of heaters or the cooling capacity of air conditioners.
  • The furnace has a maximum output of 80,000 Btu/h.
• "Million British thermal units (MMBtu)": A standard unit used in larger-scale energy commerce, such as for wholesale natural gas.
  • The contract was for the delivery of 10,000 MMBtu of natural gas.

Variants and Related Words

• Btu (BTU): The standard abbreviation for British thermal unit.
• Therm: A unit of heat energy equal to 100,000 British thermal units, often used for natural gas billing.
• Joule: The SI (International System of Units) unit of energy. One British thermal unit is approximately 1,055 joules.

Synonyms

• Heat unit: A general term for a unit measuring thermal energy. (Note: "British thermal unit" is a specific type of heat unit.)

Related Phrases

• Btu content: Refers to the amount of energy, measured in British thermal units, contained in a fuel or released during its combustion.
  • The Btu content of this coal sample is very high.
• Btu rating: A specification for appliances indicating their energy input or output capacity in British thermal units.
  • Check the Btu rating on the space heater before you buy it.

Noun

1. a unit of heat equal to the amount of heat required to raise one pound of water one degree Fahrenheit at one atmosphere pressure; equivalent to 251.997 calories