Fundamentals of Refrigeration Practice Test 2025 – Complete Exam Prep

In refrigeration, latent heat is a crucial concept that refers to the amount of heat energy required to change a substance from one state to another without changing its temperature. The units most commonly used to measure latent heat are BTUs (British Thermal Units).

One BTU is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. This unit is particularly relevant in refrigeration systems, where phase changes—such as from liquid to vapor—are fundamental processes in heat absorption and rejection. During these phase changes, heat is added or removed without affecting the temperature of the substance, which is the essence of latent heat.

While other units like Joules are also used to measure heat energy, BTUs are specifically favored in many refrigeration applications, especially in the United States. Watts measure power rather than heat content, and Pascals are units of pressure, which do not pertain directly to latent heat. Therefore, BTUs is the most appropriate and commonly used unit for measuring latent heat in refrigeration contexts.