What does the term BTU stand for?

BTU stands for British Thermal Unit, which is a unit of measurement used to quantify thermal energy. Specifically, one BTU represents the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit at a constant pressure. This measurement is particularly important in the heating, ventilation, and air conditioning (HVAC) industry, where it helps professionals assess the heating and cooling capacities of systems. Understanding BTUs is essential for sizing equipment and determining the effective operation of heating and cooling systems, ensuring they can efficiently meet the thermal comfort needs of spaces. The other options do not accurately define BTU, as they either misrepresent the term or use incorrectly defined sources that are not recognized in the HVAC field.