Energy-recovery ventilators (ERVs) have become increasingly common in recent years. You can find them in both residential and commercial heating, ventilation and cooling (HVAC) systems. An ERV, however, isn’t a substitute for a traditional air conditioner and furnace. Instead, it lives up to its namesake by “recovering” some of the thermal energy produced by an HVAC system.
The Basics of ERVs
ERVs are systems that are used to recover thermal energy in a ventilated building or home. Assuming your home is ventilated, some of the thermal energy produced by your HVAC system will be lost. Ventilation means that fresh outdoor air will enter your home, thereby replacing the old indoor air. In doing so, your home will lose some of its conditioned air, which is thermal energy.
The purpose of an ERV is to minimize the loss of thermal energy due to ventilation. It will recover some of the thermal energy in the old indoor air before exhausting it. Without an ERV, a substantial amount of thermal energy will be lost from ventilation.
How ERVs Work
While there are different types, most ERVs work in the same way. They consist of a heat exchanger that’s connected to a ventilation system. When indoor air is exhausted outside of your home, it will pass through the ERV. When fresh outdoor air enters your home, it will also pass through the ERV. The ERV will exchange some of the heat and humidity in the air while subsequently recovering thermal energy from it.
If you’re running the air conditioner on a hot summer day, the ERV will essentially cool and dehumidify the fresh outdoor air before it enters your home. If you’re running the furnace on a cold winter day, conversely, the ERV will warm the fresh outdoor air before it enters your home.
Benefits of Using an ERV
One of the main benefits of using an ERV is increased HVAC efficiency. Some ERVs have an efficiency rating of 50%, whereas others have an efficiency rating of 70% or even 80%. With an ERV, your HVAC system will be more efficient because it will lose less thermal energy due to ventilation.
You can also use an ERV to control the humidity level inside of your home. ERVs don’t just minimize the loss of thermal energy; they regulate humidity. If your home suffers from high humidity during the summer, you want to invest in an ERV. It will help to control indoor moisture vapor so that it doesn’t cause high humidity.