Definition

1. Noun:
   • A unit of heat: Specifically, a British Thermal Unit (BTU) is a traditional unit of energy defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit at a specified pressure (one atmosphere).

Usage

• The term "BTU" is used primarily in the power, steam generation, heating, and air conditioning industries to quantify energy content, heat output, or cooling capacity.
• It is a standard measurement for comparing the efficiency of appliances like furnaces, air conditioners, and water heaters.

Examples

• Noun:
  • This air conditioner has a cooling capacity of 12,000 BTUs per hour.
  • Natural gas is often sold by the therm, a unit equal to 100,000 BTUs.

Advanced Usage

• "BTU/hr" or "BTU per hour": A common rate measurement indicating power, often used for heating and cooling systems.
  • The furnace's output is rated at 80,000 BTU/hr.

Variants and Related Words

• British Thermal Unit: The full name for BTU.
• Therm: A unit of heat energy equal to 100,000 BTUs.
• MMBtu: One million BTUs, commonly used in commercial energy markets.
• Quad: One quadrillion (10^15) BTUs, used for discussing large-scale national or global energy consumption.

Synonyms

• Heat unit: A general term for any unit measuring thermal energy.

Notes

• The precise modern definition relates it to the International System of Units (SI), where 1 BTU is approximately 1055.06 joules.
• The calorie is another unit of heat; the definition states 1 BTU is equivalent to approximately 252 calories (specifically 251.997 as noted in the reference).

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