Which characteristic of the evaporator's first coil section indicates it is absorbing sensible heat?

The characteristic indicating that the evaporator's first coil section is absorbing sensible heat is when it contains mainly low-pressure liquid refrigerant. In this state, the refrigerant is transitioning from a liquid to a vapor as it absorbs heat from the surrounding environment. This phase change process illustrates the concept of sensible heat, where heat is added to the refrigerant without changing its state (meaning it doesn’t yet boil and turn into vapor). As the low-pressure liquid refrigerant absorbs heat, it warms up and eventually reaches its boiling point, beginning the transition into vapor.

The other characteristics reflect different phases or states of refrigerant. For example, being completely filled with vapor would signify that the refrigerant is already in its gaseous state and may not be absorbing sensible heat. If the evaporator section is at its boiling point, while it could be absorbing latent heat during the boiling process, it does not primarily indicate sensible heat absorption at that moment. Being superheated means that the refrigerant is in a gaseous state above its boiling point, which also would not demonstrate sensible heat absorption in the initial coil section.