Quelle est la différence entre un Échangeur d'Air VRC et VRE?
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What is the difference between HRV and ERV Air Exchangers?

The HRV vs ERV Conundrum: An Extensive Guide

As Montreal's premier HVAC (Heating, Ventilation, and Air Conditioning) company, AirGreen prides itself on providing top-notch air solutions that enhance the quality and comfort of indoor environments. Among the vital tools in our offerings are Heat Recovery Ventilators (HRV) and Energy Recovery Ventilators (ERV), two sophisticated types of air exchangers. While both devices serve a similar purpose of ventilating your indoor spaces, there are crucial differences between them. This in-depth article will demystify these differences and guide you in choosing the right solution for your needs.

Understanding Heat Recovery Ventilators (HRVs)

An HRV is an advanced type of air exchanger that efficiently manages your indoor air quality by expelling stale indoor air and bringing in fresh outdoor air. However, HRVs also recover heat from the exhausted indoor air and transfer it to the incoming air during the colder months, while reversing the process in the summer. This heat transfer mechanism makes HRVs an energy-efficient choice for many homes and businesses.

Understanding Energy Recovery Ventilators (ERVs)

Much like an HRV, an ERV also continuously replaces stale indoor air with fresh outdoor air. An ERV also recovers heat from the exhausted air. However, ERVs have an added function: they also transfer moisture between the outgoing and incoming air. This moisture exchange allows ERVs to control humidity levels in the indoor environment, which is particularly beneficial in areas with significant seasonal humidity variations like Montreal.

HRV Vs ERV: Spotting the Differences

While both HRVs and ERVs are designed to improve indoor air quality and enhance energy efficiency, they cater to different ventilation needs. Here are the key differences:

  • Humidity Control: The most significant difference between an HRV and an ERV is how they handle humidity. An HRV only transfers heat, so it does not affect the indoor humidity level. Conversely, an ERV transfers both heat and moisture, allowing it to regulate indoor humidity, a critical feature for climates with significant humidity variations.
  • Suitability for Different Climates: HRVs are generally more suitable for colder, drier climates, as they remove excess moisture from the indoor air during winter, reducing the likelihood of condensation on windows. On the other hand, ERVs are more suitable for areas with hot, humid summers or cold, damp winters, as they can reduce the moisture in the incoming air during the humid season and retain indoor humidity during the dry season.
  • Energy Efficiency: Both systems are energy-efficient as they reduce the load on your heating or cooling system by pre-conditioning the incoming air. However, ERVs might have a slight edge in very humid or dry conditions because they also manage moisture levels, reducing the need for dehumidifiers or humidifiers.

Choosing Between an HRV and an ERV

The decision between an HRV and an ERV depends on various factors such as your local climate, the building's air-tightness, and your specific needs. As a general rule:

  • Choose an HRV if you live in a colder climate with little humidity variation throughout the year and your primary concern is heat recovery and ventilation.
  • Choose an ERV if you live in a climate with significant humidity variation, and your primary concern is both heat recovery and humidity control.

At AirGreen, our HVAC experts can conduct a comprehensive assessment of your building and provide recommendations tailored to your specific needs, ensuring you choose the right system.


In summary, both HRVs and ERVs are valuable components in a comprehensive HVAC system, providing high-quality indoor air and energy efficiency. However, the choice between an HRV and an ERV depends on your unique requirements, including local climate conditions and the need to control indoor humidity. As a trusted HVAC provider in Montreal, AirGreen is dedicated to assisting you in navigating these choices, ensuring you enjoy a comfortable and healthy indoor environment.