7/30/2015

Advantages of Installing an ERV in an Older Home

Older homes often have several problems affecting energy efficiency and comfort. Air leaks around seals, windows, and doors are common and allow heated or cooled air to escape while allowing outside contaminants and humidity in. Insulation is often missing or inadequate, further increasing the difficulties with controlling the temperature. Installing an ERV, or Energy Recovery Ventilator, in an older home can help to mitigate these issues and improve both comfort and energy efficiency.

What Does an ERV Do?

An ERV removes stale air from a home and replaces it with fresh outdoor air. To do this, the ERV sucks air from vents that are strategically positioned in areas of the home that generally produce a lot of moisture or are in need of more active ventilation, such as bathrooms, kitchens, and basements.

The outgoing air moves through the ducts and to an exterior vent, passing through a box with air channels on the way out. As outdoor air is pulled into the home, it passes through the box and moves through channels that alternate with the outgoing air, which allows energy and humidity to transfer from one source to the other.

Reverses Home Air Pressure

One way that an ERV helps to improve air quality in older homes is by changing negative indoor air pressure to slightly positive indoor air pressure. Negative indoor air pressure allows outdoor air to be passively pulled into the home along with humidity and contaminants. This can cause mold to form in the walls and can decrease the quality of the indoor air. Positive indoor air pressure creates an air flow in the opposite direction, pushing stale air out of the home and reducing contaminant levels.

Reduces Strain on Heating and Cooling Units

When heat energy is passed from outgoing air to incoming air or vice versa, it helps to heat or cool the incoming air, which limits the amount of work that a heating or cooling system needs to do. An ERV always transfers the heat energy from the warmer air to the cooler air. This help to reduce a home’s overall energy usage, reduce heating and cooling costs, and improve comfort levels.

In hotter months, the outgoing air is cooler, so the heat energy moves from the incoming airflow to the outgoing air flow and is vented out before it enters the home. In cooler months, the air moving out of the home is warmer, so the heat energy moves from the outgoing air to the incoming air, heating the air before it enters the home.

Helps to Control Moisture

Moisture buildup inside of a home can cause mold to grow, which can put occupants’ health at risk and cause damage to the home. An ERV helps to control moisture in much the same way that it controls heat. As outgoing and incoming air pass moving in opposite directions, moisture transfers from the air that has higher levels of humidity to the air that has lower humidity. This helps to humidify the home when indoor air is dry and dehumidify the home when indoor air is moist.