Explain the term "latent heat" as it relates to heat pumps.

Latent heat refers to the heat absorbed or released by a substance during a phase change without a change in temperature. In the context of heat pumps, this concept is crucial because heat pumps operate by moving refrigerant through various phases (liquid and gas) to transfer heat.

When a refrigerant evaporates, it absorbs latent heat from its environment, which allows it to extract heat from a space that needs to be cooled. Conversely, when the refrigerant condenses, it releases this latent heat, transferring warmth to the area it is heating. This ability to absorb and release latent heat is what enables heat pumps to efficiently transfer thermal energy between spaces, optimizing heating and cooling processes.

Understanding latent heat is fundamental to grasping how heat pumps function in transferring heat. The other options do not capture the essence of latent heat’s role in the phase change of the refrigerant, and therefore do not reflect the accurate definition needed in this context.