By Arnaldo Perez-Negron

Home building has come a long way in the last 50 years. New standards for improved insulation values and air-tightness have enabled huge boosts in energy efficiency. But these improvements come with a risk of poor indoor air quality and moisture retention. Adding managed ventilation systems retains energy efficiency through heat recovery, while optimizing interior moisture, and providing fresh filtered air into your home. Heat Recovery Ventilation (HRV) and Energy Recovery Ventilation (ERV) are air exchange systems that not only offer great benefits for your home and your health, but can also help in saving money from your utility bills.

Both systems have similarities including providing fresh filtered air and recovering energy from exhaust air. One important thing to keep in mind is that the exhaust air and the fresh filtered air never come in contact, passing via two different airways. The energy exchange occurs in the core through a process called heat conduction, in which heat is passed from outward vented air to incoming external air of a different temperature (or vice versa in summer). This retains the benefits of the interior conditioned air.

WHAT’S THE DIFFERENCE?

Now you may be wondering, what is the difference between HRVs and ERVs and which one should I choose for my home? Both systems are physically similar. However, the difference lies in moisture, also referred to as humidity. An HRV only captures heat in its exchange mechanism. While on the other hand, ERVs are able to capture both heat and humidity. 

WHICH ONE IS BEST?

If you were to take some time to research which system is best for you, you would need to answer the following question: What type of climate do I live in? There are two conflicting responses to your answer. One answer would say, if you live on the West side of the United States, then HRVs are generally used, while if you live on the East side of the United States, ERVs are generally used. Another response is that in warmer and more humid regions it is best to use HRVs, as they won’t bring extra humidity into your home, while in colder and dryer regions an ERV would help in maintaining humidity in your home. Both answers are partially correct, but in reality the true answer is, it depends.

By considering local climate, humidity levels in your home, and personal preference, one will be best equipped to make a decision. If your home is very humid, regardless if in a cold or warm region, and you would prefer it to be less humid while getting the benefits of an air exchange system, then you can consider an HRV a better option since it will help lower humidity levels. If your home is already dry, then an ERV system could be best as it won’t allow for further depletion of humidity. Regardless of which system you use, both systems can help your home become more energy efficient and healthier.

Watch this short video for a great overview of how these systems work.

A common complaint of some HRV and ERV systems is that they are noisy in operation. Small Planet Supply, a company dedicated to supply, education, and training in the use of energy-efficient building materials and practices, explains that noise is what defines quality within the different brands. One of the top performing HRV and ERV systems is the Zehnder ComfoSystems. These systems offer constant clean and fresh air while remaining extremely quiet and performing at the highest level. Since we spend so much of our time at home, our indoor living environments are good places to actively care for our overall health, starting with the very air we breathe.

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