What does 'latent heat' refer to in refrigeration?

Latent heat refers specifically to the amount of energy absorbed or released by a substance during a phase change that occurs at a constant temperature. In the context of refrigeration, this is essential to understand how refrigerants work as they transition between different states, such as from liquid to vapor and vice versa.

During evaporation, for instance, a refrigerant absorbs latent heat from the environment, allowing it to cool the surrounding air or surface. Conversely, when the refrigerant condenses from vapor to liquid, it releases latent heat. This concept is fundamental in refrigeration systems, as the efficient transfer of heat during these phase changes is what allows for effective cooling and temperature control within the system.

The other options deal with different concepts. The energy lost during operation is not the same as latent heat, as that relates to inefficiencies in the system. Heat transferred to the surrounding environment does not specifically encompass the idea of latent heat, which focuses solely on heat involved in phase changes. Lastly, the temperature at which refrigerants boil is part of thermodynamic properties but does not define latent heat itself. Understanding latent heat's role in phase changes is crucial for anyone working within refrigeration and air conditioning mechanics.