HVAC Metering Devices Practice Test 2026 - Free HVAC Practice Questions and Study Guide

A filter drier is installed between the liquid line or condenser and the capillary tube to prevent contaminants from entering the capillary tube. This device plays a critical role in the refrigeration system by filtering out moisture, which can cause corrosion, and capturing particulates that can clog the small passages of the capillary tube. If contaminants were to enter the system, they could lead to significant operational issues or even failure of the HVAC system due to blockages or chemical reactions.

The capillary tube, being a small diameter tubing, is particularly susceptible to blockages from debris and moisture. Installing a filter drier helps maintain system efficiency and prolongs the lifespan of the HVAC components. Proper filtration ensures that only clean refrigerant enters the capillary tube, allowing for optimal performance of the refrigeration cycle.