ESCO Air Conditioning Practice Exam 2026 – Complete Study Resource

A capillary tube metering device is recognized for its simplicity and low cost, making it an attractive option for many refrigeration and air conditioning systems, particularly in smaller applications. It functions as a flow restrictor that utilizes the pressure differential created by the refrigerant cycle to regulate the flow of refrigerant into the evaporator.

While they are indeed capable of supporting certain operational conditions, capillary tube metering devices do not handle variable loads effectively. This is largely due to their fixed orifice design, which means that the flow is dictated solely by the refrigerant pressure and temperature, regardless of the system's demand. This can lead to inefficiencies or inadequate cooling during periods of fluctuating load, as it cannot adjust dynamically to changes in cooling requirements.

On the other hand, their ability to maintain a consistent refrigerant flow stems from this fixed-orifice function, which can be advantageous in stable operating conditions. Additionally, they find their niche in smaller systems, such as residential air conditioning units, where the simplicity of design aligns with the nature of the load.