Btu (I.T.)
The British thermal unit (International Table), Btu (IT), is about 1,055 joules, roughly the energy needed to warm one pound of water by one degree Fahrenheit. In the United States air conditioners and furnaces are rated in Btu per hour.
Foot-pounds
A foot-pound (ft-lb) is a unit of work or energy in the Imperial and U.S. customary systems that is the amount of energy required to exert a force of one pound over a distance of one foot.