The
therm (symbol
thm) is a non-
SI unit of
heat energy. It was defined in the
United States in 1968 as the energy equivalent of burning 100
cubic feet of
natural gas at standard temperature and pressure. In the US gas industry its SI equivalent is defined as exactly 100,000 BTU
59°F or 105.4804 mega
joules.
Public utilities in the U.S. use the therm unit for measuring customer usage of gas and calculating the monthly bills. In the
European Union it was defined in 1979 as exactly 100,000 BTU
IT or 105.505 585 262 megajoules. The unit was abolished in the
United Kingdom in 1999.
Category:Units of energy