Air Conditioning Repair Certification (ETI) Practice Exam 2025 - Free Air Conditioning Repair Practice Questions and Study Guide

A capillary tube metering device is designed to provide a constant flow of refrigerant based on the pressure difference between the high and low sides of the system, rather than adjusting flow based on varying conditions. The statement that it can be used in high-capacity applications is not true because capillary tubes are generally best suited for low-capacity systems. They lack the ability to meter refrigerant flow dynamically, which is necessary for managing high-capacity systems that experience significant variations in load.

In contrast, capillary tubes are indeed gravity dependent, meaning that their performance can be affected by the orientation of the system, particularly in systems that are installed at various angles. This characteristic affects how the refrigerant flows through the tube. Furthermore, these devices do not provide any control over superheat; they have a fixed orifice size, which does not allow for adjustments based on the superheat requirements of the system, unlike other metering devices that can regulate flow according to varying conditions. This understanding of capillary tube operation clarifies why the statement regarding their use in high-capacity applications is not accurate.