What does the term "latent heat" refer to in refrigeration?

The term "latent heat" specifically refers to the heat absorbed or released by a substance during a phase change, without a change in temperature. In the context of refrigeration, understanding latent heat is critical because it explains how refrigerants absorb heat from the environment or release heat, allowing for effective temperature control within the refrigeration cycle.

For example, when a refrigerant evaporates from a liquid to a gas, it absorbs latent heat from its surroundings, cooling the area effectively. This process occurs without a temperature increase during the phase change itself, which is a key characteristic of latent heat. This concept is essential for the operation of refrigeration systems, as it highlights the importance of material phase transformations in managing heat transfer.

In contrast, other terms in the choices involve different concepts. Heat causing temperature change relates to sensible heat rather than latent heat. Heat lost during expansion refers to the process of work done by the refrigerant during its phase transitions but does not specifically define latent heat. Lastly, the heat capacity of the refrigerant pertains to how much heat energy a substance can store per unit of temperature increase, not to the transfer of heat during a phase change, which is what latent heat encompasses.