Calories (15 °C, NBS 1939)
The 15 °C NBS 1939 calorie is the amount of energy required to raise the temperature of one gram of water by one degree Celsius, from 14.5 °C to 15.5 °C, at standard atmospheric pressure. This specific definition was established by the National Bureau of Standards (NBS) in 1939.
Therm (EC)
The Therm (EC) is a unit of energy primarily used in the United Kingdom for billing purposes in the gas industry. It is defined as 105.5 megajoules (MJ). The "EC" in Therm (EC) stands for European Community as it was created to standardize within European countries.