HVAC - EPA Certification Practice Exam 2025 - Free EPA Certification Practice Questions and Study Guide

The primary function of a filter drier in an HVAC system is to remove moisture from refrigerant. This is crucial because moisture can cause several problems in HVAC systems, including corrosion of metal components, reduced efficiency, and the formation of acidic byproducts that can damage the compressor and other vital parts.

The filter drier operates by containing desiccant materials that absorb moisture from the refrigerant, thereby preventing the potential for ice formation in the metering device and ensuring that the system runs smoothly. In doing so, it helps maintain the integrity and efficiency of the entire cooling system.

While the other options describe functions that may relate to HVAC systems, they do not accurately define the specific role of a filter drier. Enhancing cooling efficiency and increasing airflow pertain to overall system performance rather than moisture control, and regulating temperature is a function of the thermostat and overall system design rather than the filter drier itself.