What does BTU stand for, and what does it measure?

The term BTU stands for British Thermal Unit, and it specifically measures heat energy. A British Thermal Unit is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit at constant pressure. This unit is commonly used in heating and cooling applications, helping HVAC professionals quantify the energy required for heating spaces or transferring heat in air conditioning systems.

Understanding the BTU is fundamental in HVAC as it enables technicians to determine the proper sizing of heating and cooling equipment. By knowing the BTUs needed for a particular area, they can select units that will efficiently meet the heating or cooling demands of a residential or commercial space.