What unit would you primarily use to measure cooling capacity in HVAC systems?

In HVAC systems, cooling capacity is primarily measured in BTUs, or British Thermal Units. This unit is used to quantify the amount of heat energy that can be removed from a space in one hour. A BTU is defined as the amount of heat required to increase the temperature of one pound of water by one degree Fahrenheit. This makes it particularly relevant for HVAC applications, where the goal is to control temperature and humidity within a given environment.

Using BTUs allows HVAC professionals to effectively assess and compare the ability of various cooling systems to maintain comfortable conditions. For example, a system's cooling capacity is often indicated in BTUs per hour, which directly correlates with how much heat energy it can remove from an indoor space.

While watts, kilojoules, and horsepower are all units of energy or power, they do not specifically relate to the standard measures used in the heating and cooling industry. Watts are typically used to measure electrical power, kilojoules are a metric energy unit, and horsepower is used for measuring engine power. Therefore, BTUs remain the most applicable and widely recognized unit for expressing cooling capacity in HVAC systems.