Rate of work in HVAC systems is typically measured in what unit?

In HVAC systems, the rate of work is often measured in BTUs per hour (Btu/hr). This unit is particularly relevant because it quantifies the amount of heat energy that an HVAC system can transfer in one hour, whether in heating or cooling processes. Specifically, BTUs measure the energy needed to raise the temperature of one pound of water by one degree Fahrenheit, making it a suitable choice for understanding heating and cooling capacities in buildings.

While watts, joules, and horsepower are related to energy and power, they are not as commonly used in the HVAC industry for this specific application. Watts and joules are more frequently associated with electrical systems, and horsepower is often used in mechanical contexts or for engines rather than directly in HVAC equipment ratings. Thus, Btu/hr is the preferred and most widely recognized unit for gauging the rate of work or energy output in HVAC systems.