What effect does a thermostatic expansion valve with a discharge power element have on the evaporator?

The correct answer relates to the specific function of a thermostatic expansion valve (TXV) equipped with a discharge power element, which is designed to precisely control the flow of refrigerant into the evaporator.

In this scenario, when the evaporator experiences a starved condition, it indicates that insufficient refrigerant is entering the evaporator, leading to a reduction in cooling capacity and inefficient operation. The discharge power element in the TXV responds to changes in the discharge pressure, adjusting the flow of refrigerant accordingly. If the pressure is too low, it could result in the valve restricting refrigerant flow even further, causing a starved evaporator where the surface area of the evaporator is not fully utilized. This can happen if the system is low on refrigerant or if there is an obstruction or improper functioning of the valve itself.

Therefore, the condition of a starved evaporator is accurately characterized by the implication that the unit isn’t receiving enough refrigerant for proper heat exchange, ultimately leading to ineffective cooling and potential system damage if not addressed.