What type of system typically uses a fixed orifice as a metering device?

A fixed orifice is a metering device commonly found in refrigeration systems. This device is used to control the flow of refrigerant in various applications, such as in evaporators within refrigeration cycles. The principal characteristic of a fixed orifice is that it allows a consistent flow rate of refrigerant, regardless of the pressure differences that may occur in the system. This makes it particularly useful in refrigeration systems, where the operational conditions tend to be stable and predictable.

In contrast, heat pump systems and large commercial chillers may use other types of metering devices like expansion valves, which can adjust the flow based on varying conditions to optimize performance and efficiency. By using a fixed orifice, refrigeration systems can maintain a simpler and more cost-effective design, given that they do not require the complexity of variable adjustments that other systems might need.