Is it worth installing an ERV or HRV?

Sometimes, improvements in one area can result in setbacks in another. For example, in recent years there has been a push for more energy efficient homes and comfortable living spaces. This is an improvement. However, homes that are better insulated, or “tighter” can often have poor indoor air quality since there is no “fresh” air blowing in through cracks in the building envelope. This is a setback because an adequate quantity and quality of ventilation and airflow are essential for healthy living. Why? Here’s what proper ventilation accomplishes:

  • To provide enough fresh air to keep the occupants healthy
  • To remove odors
  • To dilute indoor pollutants
  • To lower the indoor relative humidity

These reasons all are common sense, although the issue of indoor relative humidity may be a little abstract to most homeowners. Here’s a quick synopsis.

The story on humidity

The higher the humidity in a home, the less comfortable the air will feel during warm seasons. It can also promote the growth of mildew, or worse yet of mold, which is a definite health hazard. On the other side, the lower the humidity the less comfortable the air will feel during cold seasons. It can also cause dry skin and even negatively affect wood furniture or wooden floors. So, the key is maintaining the proper level of humidity which is generally between 35% and 60%.

Using outside air to ventilate a house can help lower the indoor humidity, but only if it is cold outside, since cold air normally has less moisture in it than warm air. But of course that means brining in cold air and having to heat it up. On the other hand, in most parts of the country, ventilating a house during warm or hot weather usually brings more moisture into the house raising the humidity. And of course, it means cooling it back down to keep the house comfortable.

How ventilating helps

More than likely, your home has one of these three ventilation options: 1) an exhaust-only ventilation system; 2) a central-fan-integrated supply ventilation system; or 3) a balanced ventilation system using an energy-recovery ventilator (“ERV”) or a heat-recovery ventilator (“HRV”).

The first option usually means there is an exhaust fan in the bathroom and kitchen. They get used enough that some fresh air is being pulled in on a regular enough basis through open doors or windows to provide basic ventilation. The second option is the same as the first except that there is also a fan that blows air into the home to replace what is being exhausted. This is necessary in the case of a tightly sealed and insulated home. Both of these two have the downside of an increase in energy demand. As we mentioned earlier, any air that is brought in from outside the home has to be heated or cooled to keep the house comfortable. More fresh air means higher utility bills.

That’s where the third option comes in. An ERV or an HRV is designed to reduce the cost of needing to condition fresh air. The upfront cost of installation may be relatively expensive, but they have the lowest operating cost of any ventilation option.

The story with ERVs and HRVs

To sum it up, an ERV or an HRV delivers fresh air to a home and exhausts stale air. Neither is designed to provide makeup air for fuel burning appliances like gas furnaces or gas ovens. They also are not meant to exhaust odors like the fans in a kitchen or bathroom. They also do not directly heat or cool the air coming into the home. Instead, they reduce the amount of heating or cooling that your system must do to the fresh air that is coming into the house.

And that is where it makes it worth installing an ERV or an HRV. Want to know more? Come back for the next part where we’ll explain the difference between the two and help you decide which is better for your home.

If you would like more information on how we can help you with your up-coming project to install an indoor air quality accessory in your home in the Beverly Hills, Culver City, Mar Vista, Miracle Mile, Hollywood, West Hollywood, Los Angeles, West Los Angeles, Santa Monica, Marina Del Rey, Pacific Palisades, Brentwood, Bel Air, Westwood, Downtown Los Angeles, Vernon, Huntington Park, Sherman Oaks, Encino area, please give GAMA Air a call at (310) 651-6936 or use our online form to request a free visit with no obligation.

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