What does the term "BTU" stand for?

The term "BTU" stands for British Thermal Unit, which is a standard unit of measurement for energy. Specifically, it is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit at a constant pressure. This unit is commonly used in the HVAC industry to quantify the amount of heat energy needed for heating and cooling systems. Understanding BTUs is essential for calculating the appropriate size and capacity of heating and cooling equipment for residential and commercial applications. The other options do not accurately represent the meaning of BTU or its significance in the context of thermal energy measurement.