In an air-conditioning system that uses a thermostatic expansion valve, the temperature of the evaporator outlet is typically:

In an air-conditioning system using a thermostatic expansion valve, the temperature of the evaporator outlet is typically warmer than at the evaporator inlet. This phenomenon occurs because the evaporator's primary function is to absorb heat from the surrounding environment, which causes the refrigerant to evaporate. As the refrigerant passes through the evaporator coil, it takes in heat from the indoor air (or space) and changes from a low-pressure liquid to a low-pressure vapor.

This heat absorption results in a decrease in temperature at the evaporator inlet, where the liquid refrigerant enters, and an increase in temperature at the outlet, where the vapor refrigerant exits. The difference in temperature indicates that heat transfer has occurred. This process is essential for the system's efficiency, as it allows for effective cooling by removing heat from the air inside the space.

While other options may suggest scenarios that could occur under different conditions, they do not align with the typical functioning of an air-conditioning system using a thermostatic expansion valve, where effective heat absorption leads to an increase in temperature from the inlet to the outlet of the evaporator.