What is Energy Recovery Ventilator

An Energy Recovery Ventilator (ERV) is a ventilation system that helps improve indoor air quality while simultaneously conserving energy. It is commonly used in residential and commercial buildings to bring in fresh outdoor air and exhaust stale indoor air, all while recovering the energy from the outgoing air stream.

The main purpose of an ERV is to provide ventilation while minimizing the loss of heating or cooling energy. It achieves this through a heat exchanger that transfers heat and moisture between the incoming and outgoing air streams. Here's how an ERV works:

1. Air Exchange: The ERV is connected to the building's HVAC (heating, ventilation, and air conditioning) system, where it exchanges the indoor and outdoor air. Stale indoor air is exhausted from the building, while fresh outdoor air is brought in.

2. Heat Transfer: Within the ERV unit, the incoming and outgoing air streams pass through separate channels. The heat exchanger core facilitates the transfer of heat between the two air streams. During the winter, the heat exchanger transfers the warmth from the outgoing indoor air to the incoming cold outdoor air, preheating it before it enters the building. In the summer, the process is reversed, with the heat exchanger transferring the coolness from the outgoing indoor air to the incoming hot outdoor air, precooling it.

3. Moisture Transfer: Along with heat, an ERV can also transfer moisture between the air streams. This helps to maintain a balanced humidity level in the building. In humid conditions, moisture from the incoming air is transferred to the outgoing air, reducing the humidity level indoors. In dry conditions, moisture from the outgoing air is transferred to the incoming air, increasing the humidity level indoors.

4. Filtration: ERVs typically include filters to remove particulates, dust, pollen, and other airborne contaminants from the incoming air. This helps improve indoor air quality by reducing the presence of allergens and pollutants.

The benefits of an Energy Recovery Ventilator include:

1. Improved Indoor Air Quality: ERVs provide a continuous supply of fresh outdoor air while removing stale indoor air. This helps remove pollutants, odors, and excess humidity, resulting in improved indoor air quality.

2. Energy Efficiency: By transferring heat and moisture between the incoming and outgoing air streams, ERVs help reduce the load on heating and cooling systems. This leads to energy savings and improved energy efficiency in the building.

3. Balanced Humidity: The moisture transfer capability of ERVs helps maintain a balanced humidity level indoors, preventing overly dry or humid conditions. This is particularly beneficial for occupant comfort and preventing issues associated with high or low humidity.

4. Cost Savings: With reduced energy consumption, an ERV can contribute to lower heating and cooling costs over time.

5. Comfort and Health: By ensuring a constant supply of fresh air, ERVs create a more comfortable and healthier indoor environment by reducing stuffiness, odors, and the buildup of indoor pollutants.

It's worth noting that ERVs are different from Heat Recovery Ventilators (HRVs), which primarily focus on heat transfer and do not transfer moisture between the air streams. ERVs, on the other hand, provide both heat and moisture transfer capabilities.