Btu (I.T.)
The British Thermal Unit (International Table) is a unit of energy commonly used in the United States defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit at a constant pressure of one atmosphere.
Newton-meters
A newton-meter (Nm) is primarily used to quantify torque which is the rotational force applied to an object. It is the force of one newton applied perpendicularly to a lever arm one meter long.