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

The component that is essential for measuring the pressure of refrigerants during maintenance is the manifold gauge set. This equipment is specifically designed to provide accurate readings of both high and low refrigerant pressures within an HVAC system. The gauges on the manifold allow technicians to monitor the system's performance, diagnose issues, and ensure that the refrigerant charge is appropriate for optimal operation.

By using the manifold gauge set, technicians can determine if the system is operating within the manufacturer's specified pressure ranges, which is crucial for effective troubleshooting. This set is also used to evacuate the system, check for leaks, and recharge the refrigerant, making it an indispensable tool in HVAC maintenance and repair.

In contrast, other options such as the capillary tube, thermostat, and expansion valve serve different functions within the HVAC system. The capillary tube is primarily involved in controlling refrigerant flow, while the thermostat regulates temperature. The expansion valve, on the other hand, controls the flow of refrigerant into the evaporator coil. None of these components provide the functionality necessary for measuring refrigerant pressures during maintenance.