What type of heat transfer occurs in the evaporator?

In the evaporator, latent heat transfer occurs as the refrigerant absorbs heat from the surrounding environment, which causes the refrigerant to change state from a liquid to a vapor. This process is essential to the operation of refrigeration systems, as it allows the refrigerant to cool the air or fluid that passes over or through the evaporator.

Latent heat transfer is specifically concerned with the heat energy required for a substance to change its state without a change in temperature. In the case of the evaporator, the refrigerant enters in a low-pressure liquid form, absorbs heat, and evaporates into a gas. This heat absorption is what achieves the cooling effect necessary in refrigeration cycles.

Other types of heat transfer, while important in various contexts, do not accurately describe the primary mechanism at work within the evaporator. Conduction involves heat transfer through direct contact, convection refers to heat transfer through fluid motion, and radiant transfer involves energy transfer through electromagnetic waves. These concepts may play a role in different stages or components of a refrigeration system, but they do not characterize the main action occurring in the evaporator like latent heat transfer does.