In HVAC terminology, what does BTU represent?

BTU stands for British Thermal Unit, which is a standard unit of measurement used in the HVAC industry to quantify the amount of heat energy. Specifically, one BTU is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. Understanding BTU is crucial because it helps in assessing the heating and cooling capacity of HVAC systems. This measurement allows HVAC professionals to size equipment appropriately for various applications, ensuring efficiency and comfort in climate control systems.

The other terms provided in the choices do not accurately represent this widely recognized measurement in HVAC terminology. Hence, they are not applicable in this context.