Question 174Refrigeration & AC - Assistant Engineer

The correct answer is C) temperature of the evaporator coil outlet. In a refrigeration system, the pressure within the power element of a thermostatic expansion valve depends directly on the temperature of the refrigerant leaving the evaporator coil. This is because the power element is connected to the outlet of the evaporator, and the pressure it experiences is a function of the temperature at that point. As the evaporator coil outlet temperature changes, the pressure in the power element changes accordingly, which then adjusts the opening of the expansion valve to maintain the desired superheat. The other answer choices are incorrect because they do not directly determine the pressure in the power element. The compressor suction pressure (A) and the temperature in the box (B) affect the system but do not directly influence the pressure in the power element. The heat transferred from the saturated liquid in the evaporator (D) is a result of the temperature at the evaporator outlet, not a direct determinant of the power element pressure.