What is a British thermal unit (BTU) used to measure?

A British thermal unit (BTU) is a unit of measurement specifically used to quantify heat energy. It represents the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit at a constant pressure. This makes BTUs particularly relevant in the fields of heating, ventilation, air conditioning, and refrigeration, where understanding energy transfer is crucial for the design and operation of systems that manage temperature.

Understanding BTUs is essential for anyone involved in HVAC systems because it helps in calculating heating and cooling loads, which are necessary for ensuring efficiency and comfort in indoor environments. This measure is particularly useful for comparing the heat output of different heating appliances, such as boilers, furnaces, and heat pumps.