BTU (British Thermal Unit)
The energy needed to raise 1 pound of water by 1 °F — approximately 1,055 joules.
Definition
The British Thermal Unit (BTU or Btu) is a traditional unit of heat energy. It is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. It is commonly used in the US for heating, air conditioning, and power plant ratings.
Formula
1 BTU = 1,055.06 J = 0.000293 kWh
Examples
- A typical home HVAC system is rated at 12,000–60,000 BTU/hour.
- One cubic foot of natural gas releases about 1,020 BTU when burned.