Final answer:
The statement is true, as an Automatic Expansion Valve (AXV) is most efficient under constant evaporator load conditions, regulating the refrigerant flow to maintain consistent superheat and prevent inefficiencies.
Step-by-step explanation:
The statement 'an AXV works best when the evaporator load is constant' is TRUE. AXV stands for Automatic Expansion Valve, which is a device used in refrigeration and air conditioning systems to regulate the flow of refrigerant according to the evaporator load. The efficiency of an AXV is highest when the load remains constant because the valve is designed to maintain a consistent superheat by adjusting the refrigerant flow based on the temperature and pressure conditions that correspond to a steady load. When the load fluctuates significantly, the AXV may not respond quickly enough to changes, leading to inefficiencies such as underfeeding or overfeeding of the refrigerant, which can result in less effective cooling or potential damage to the system.