Heat recovery ventilators (HRV) and energy recovery ventilators (ERV) are air exchange systems that help to enhance indoor air quality and minimize heating costs. They retain existing heat and optimize the interior moisture content in the air. These mechanical systems use fans to maintain a balanced airflow into the house while exhausting stale indoor air.
What is the difference between an HRV and an ERV?
HRVs and ERVs are similar devices in that both supply air to the home and exhaust stale air while recovering energy from the exhaust air in the process. The primary difference between the two is that an HRV transfers heat while an ERV transfers both heat and moisture. Both ventilation systems place the control of air quality and air exchange in the hands of the homeowner rather than relying on inherent, often inadequate, leaks in the home to provide necessary ventilation.
What are the benefits of HRV/ERV systems?
Properly selected and installed HRV and ERV units provide several benefits:
- Provide an energy-efficient means to exhaust indoor pollutants to improve indoor air quality;
- Maintain a continuous supply of fresh, filtered, and tempered outdoor air throughout the home;
- Control excess indoor humidity when outdoor humidity levels are lower;
- Recover heat from the exhaust air in winter;
- Cool incoming air in summer when the house is air-conditioned.
In addition, since ERVs have the ability to transfer moisture, they help prevent excess dryness in the cold season and reduce the demands on the air-conditioning system in the warm season.
Will an HRV/ERV save on utility costs?
Yes! In fact, mechanical ventilation systems are the only energy-efficient, effective way to ventilate a tightly built home to provide a healthy and comfortable indoor environment.
An HRV/ERV system provides critical ventilation while recovering heat and air conditioning energy which will save on energy bills. An ERV or HRV will pay for itself when compared to other mechanical ventilation options.
Which one is right for me? HRV or ERV?
An HRV and ERV are similar in that they both supply and exhaust air to and from the home while recovering energy from the exhaust air. Both are widely used throughout North America.
HRVs have been more commonly used in homes where the primary concern is high humidity in winter. ERVs are typically recommended where moderating between humidity extremes is a year round concern.
For more information, download the free HVI Heat and Energy Recovery Ventilators (HRV/ERVs) Brochure, and visit HVI’s Web site that offers a variety of resources including a Certified Products Directory.
The Healthy House Institute (HHI), a for-profit educational LLC, provides the information on HealthyHouseInstitute.com as a free service to the public. The intent is to disseminate accurate, verified and science-based information on creating healthy home environments.
While an effort is made to ensure the quality of the content and credibility of sources listed on this site, HHI provides no warranty - expressed or implied - and assumes no legal liability for the accuracy, completeness, or usefulness of any information, product or process disclosed on or in conjunction with the site. The views and opinions of the authors or originators expressed herein do not necessarily state or reflect those of HHI: its principals, executives, Board members, advisors or affiliates.
