An energy recovery ventilator (ERV) system scores high marks

An energy recovery ventilator (ERV) system scores high marks


An energy recovery ventilator (ERV) and a heat recovery ventilator (HRV) both replenish stale indoor air with fresh outdoor air. But how can you decide which system is best for your home? Here's a comparison.

Adding an energy recovery ventilator (ERV) doesn't have to compromise efficiency of your home or HVAC system.

ERVs solve the problem of a well-sealed home that holds the coveted heated and cooled air inside but also bottles up undesirable pollutants in the air supply. With its unique technology, the ERV prevents energy from escaping the home, while promoting optimal ventilation levels.

How an ERV system works

An ERV comprises components that maximize air circulation in the home while filtering outdoor pollutants and reusing energy. Here's how:

As the ERV's fan draws outside air into the unit through the intake vent, it passes through a standard air filter. At the same time, the unit pulls air from inside the home to the outdoors through the exhaust vent. Before it exits the system, the heat exchanger at the core strips energy from the air — in summer, it's cold energy; in winter, it's warm energy — and transfers that energy to the incoming supply of air.

In this way, the ERV can capture energy that would otherwise be wasted and reuse it to lower the operating costs of the system and drive energy efficiency.

Moisture control

Another key feature of the ERV is its moisture-control capacity. In fact, an ERV and heat recovery ventilator (HRV) are identical in function, with this one exception. As the ERV draws outdoor air inside, it strips the air of moisture. Otherwise, especially for homes in humid climates, running an HRV would ultimately raise indoor humidity to an uncomfortable level.

The ERV also puts its moisture-controlling abilities to work in the winter. Instead of allowing moisture to exit the home alongside the indoor air, the ERV captures moisture from that outgoing air and restores it to the home, preventing unnecessarily dry air.

Benefits of an ERV

With an understanding of how the ERV works, you can see the direct benefits that the system affords homeowners who have one installed in their home:

  • Controlled ventilation. If you were to open a window to achieve ventilation and air exchange, your home would also be subject to large amounts of energy loss, particularly in winter and summer. At certain times, ventilation through open windows and doors just isn't cost effective. With the ERV, however, you can adjust the controls to increase or reduce ventilation as needed, and you won't lose energy heating or cooling the great outdoors.
  • High efficiency. Pre-heating or -cooling the incoming air from scratch would require significant amounts of energy, and in effect, make operating a ventilation system cost-prohibitive. The ERV takes a significant bite out of energy consumption, proving that function doesn't have to come at the cost of efficiency.
  • Better indoor air quality. The ERV flushes pollutants out of the air by supplying a controlled rate of air exchange, ridding the home of harmful allergens.
  • Home comfort and preservation. The ability to control indoor relative humidity is a huge plus. Without it, high indoor humidity can lead to more than just the discomfort of family members. Higher indoor humidity levels also means homeowners have to compensate by running their A/Cs at a lower temperature, which leads to higher energy costs. Increased moisture in the home can also lead to damage to wood products, mold problems and health issues. The ERV effectively manages moisture, as you can use the controls to set the exact relative humidity you desire.

There's no better solution to poor indoor air quality, necessary ventilation and energy efficiency. The ERV offers homeowners controlled, measured air-to-air exchange while promoting optimal air quality and peak energy efficiency.

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Consider having your home's air quality tested when making changes to your insulation. (Photo courtesy of Jeff Rogers)
Consider having your home's air quality tested when making changes to your insulation. (Photo courtesy of Jeff Rogers)

Spray foam insulation will not make the home airtight without the right ventilation system in place. Check Angie's List to learn more about spray foam insulation.

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