What is a British thermal unit or Btu?
A British thermal unit (Btu) is simply a term used to measure heat energy. One Btu is the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit. It is approximately the same amount of heat you would get from burning a wooden match. One cubic foot of natural gas has about 1,031 Btu. The amount of heat in one hundred cubic feet of natural gas (1 CCF) is about 103,000 Btu. Some natural gas suppliers will measure and bill the customer for each 100,000 Btu that is delivered and this is referred to as one therm of heat energy. Rate tariffs for this kind of metering and billing will show the charge per therm used.
