A BTU is defined as amount of heat required to raise the temperature of one 1 pound (0.454 kg) of liquid water by 1 °F (0.556 °C) at a constant pressure of one atmosphere – it is used in the power steam generation heating and air conditioning industries
1 Btu/h = 2.931 W / 1000 W = 3412.14 Btu/h
