What is an energy recovery ventilation (ERV) system and when should it be used in base facilities?

• A. Exchanges energy between exhaust and incoming air to reduce heating/cooling loads; use in climate zones where ventilation energy savings justify cost, especially in high-performance buildings.
• B. Heats water for domestic use using exhaust energy.
• C. A device that recovers energy only from outside air without exchange.
• D. A filter device that reduces energy consumption by lowering airflow.

Answer: (A)

Energy recovery ventilation is a system that transfers energy between outgoing stale air and incoming fresh air, so you can ventilate for good indoor air quality without paying full heating or cooling penalties. It captures heat from the exhaust air to precondition the incoming air, and many ERVs also transfer some moisture, helping to control indoor humidity as outdoor conditions change. This makes ventilation feasible in base facilities that require continuous air exchange but want to keep energy use and humidity levels in check. ERVs are especially worthwhile in climates where the energy savings from ventilating are significant or in high‑performance buildings with tight envelopes and strict humidity control. In cold conditions, the incoming air is pre-warmed; in hot/humid conditions, the system helps temper humidity and reduces cooling and dehumidification loads. Other descriptions that miss the cross‑stream energy exchange or mischaracterize the system (such as heating water from exhaust, or recovering energy without any air exchange, or simply filtering to lower airflow) do not describe how ERVs actually function.