Refrigeration and Air Conditioning Mechanics (313A) Advanced Practice Exam

The purpose of an Energy Recovery Ventilator (ERV) in an HVAC system is to minimize energy loss and facilitate heat recovery. ERVs are designed to transfer heat and moisture between incoming fresh air and outgoing stale air. This process allows the system to condition the incoming air more efficiently, especially in heating and cooling applications.

When the warmer, stale air is exhausted from the building, it passes through the heat exchanger where it transfers some of its heat (and moisture, if needed) to the incoming, cooler air. In winter, this can help preheat the incoming air, thus reducing the overall heating demand on the HVAC system. Conversely, in summer, it helps pre-cool the incoming air. This method significantly improves energy efficiency by lessening the load on heating and cooling systems, leading to lower energy costs.

The other options mentioned—recovering water from exhaust air, ventilating areas without air conditioning, and filtering particulates from the air—do not accurately describe the primary function of an ERV. While these points may touch on aspects related to HVAC systems, they miss the specific role that ERVs play in energy efficiency and heat recovery.