How to Understand the Difference Between HRV and ERV Ventilation

How to Understand the Difference Between HRV and ERV VentilationHeat recovery ventilators (HRVs) and energy recovery ventilators (ERVs) are whole-house ventilation methods that provide the optimum option for moving air in and out without paying a penalty in heat loss or gain. With today’s tighter energy-conserving construction methods that eliminate the natural influx of fresh air, new houses don’t breathe like older homes used to. The result is indoor air stagnation and an accumulation of airborne pollutants, fumes and humidity to unhealthy, uncomfortable levels.

HRV and ERV Similarities

HRV and ERV systems have many features in common. They both induct fresh outdoor air and exhaust stagnant indoor air in equal volumes. This maintains neutral indoor air pressure critical to retaining cooling and heating.

Both systems utilize dedicated small-bore ductwork or the existing HVAC ducts to remove stagnant air from designated areas and deliver fresh outdoor air to other areas. Incorporated in the central controller is a heat exchanger that extracts heat from the warmer air stream and adds it to the cooler air stream.

During summer, heat is removed from incoming fresh air and transferred to the outgoing cooler stale air. Up to 85 percent of the heat energy is extracted, so your indoor environment is flushed with fresh air, but your A/C isn’t burdened by any heat gain. In winter, the opposite effect occurs. Heat is recovered from the exhaust air stream and added to cooler incoming fresh air to warm it up and conserve heating energy.

Depending on fan speed, both systems consume an average of about 150 watts of electricity.

The ERV Extra

An energy recovery ventilator adds an extra dimension to balanced, controlled ventilation. In addition to transferring heat like the HRV, an ERV also extracts water vapor from the moist air stream and moves it to the drier air stream. This helps reduce the accumulation of excess humidity caused by incoming fresh outdoor air during summer and also minimizes uncomfortably dry indoor air during winter.

Paitson Bros. has kept Wabash Valley homeowners comfortable and informed since 1922. For more information on HRV and ERV options, contact us today.

Our goal is to help educate our customers in Terre Haute, Indiana about energy and home comfort issues (specific to HVAC systems).  For more information about ventilation and other HVAC topics, download our free Home Comfort Resource guide.

Credit/Copyright Attribution: “iQoncept/Shutterstock”

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    Jeff Paitson Jeff Paitson is a third generation business owner who continues to run the business with the same values that have been passed down from previous generations since 1922.

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    Ethan Ethan Rayburn is a lifelong resident of Terre Haute and a 2005 graduate of Purdue University.

    An Eagle Scout, Ethan spent four years as a non-profit executive with the Boy Scouts of America before joining Paitson Bros. as a comfort advisor and later General Manager. In that role, Ethan has brought a renewed enthusiasm for customer care, integrity, value, and service to Paitson Bros. Heating & Air Conditioning.

    Ethan enjoys singing and was a member of the Purdue Varsity Glee Club. He also enjoys playing and coaching soccer, spending time with his family and two young boys, and volunteering his time and resources with his church, Terre Haute First Baptist Church, which he has attended from a very young age.
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