Btu
One BTU is the energy required to heat 1 avoirdupois pound of liquid water by 1 degree Fahrenheit, at a pressure of one atmosphere.
One BTU is the energy required to heat 1 avoirdupois pound of liquid water by 1 degree Fahrenheit, at a pressure of one atmosphere.
The mean calorie is the total amount of energy needed to heat one gram of air-free water from 0 to 100°C at standard atmospheric pressure, divided by 100.It's value is 4.19002 J