What is a major disadvantage of using a hand expansion valve?

A hand expansion valve's primary characteristic is that it allows for manual adjustment of refrigerant flow. This means the operator must physically manipulate the valve to set the flow rate based on the system's current requirements. The major disadvantage here is that it cannot automatically adjust flow in response to changing conditions, such as variations in temperature or pressure, which can lead to inefficiencies. If the system demands a different flow rate for optimal operation, an operator must be present to make these adjustments, which may result in inconsistent performance and additional labor.

In contrast, other types of expansion valves, such as electronic or thermostatic expansion valves, are able to make these adjustments automatically based on sensor inputs, providing better efficiency and performance without constant human intervention. This limitation of the hand expansion valve is critical in applications that require precise control and responsiveness to changing operating conditions.