Indirectly, the roots of the energy recovery industry can be traced back to Philadelphia in July 1976, when 34 people died of "Legionnaire's Disease", focusing attention on what would later become known as "sick building syndrome". Ventilation became the answer to Indoor Air Quality (IAQ) issues.

During ventilation, inside conditioned air that contains energy (heat and humidity), is exhausted and replaced with fresh, but unconditioned, outside air, which must then be heated, cooled, humidified and/or dehumidified.

Energy Recovery Ventilators (ERV) were invented to recover some of the energy from the exhausted air, and transfer it to the unconditioned outside air entering the building, saving as much as 15% on the building's HVAC operating costs.

Energy Recovery systems can also be used for dehumidification, or in combination with heat recovery systems to provide enhanced efficiency for HVAC systems.

Types of ERV (Energy Recovery Ventilator)

There are basically two types of ERV: Rotary Wheels, which rotate an energy recovery medium through the exhaust and outside air streams to transfer heat and humidity, and Plate Type exchangers, which use a series of stacked plates (membranes) to separate the two air streams while allowing them to be close enough to exchange heat and humidity through the plates.

Rotary Wheels are generally used for larger commercial air handler applications due to their lower cost and higher efficiencies, while Plate Type exchangers are used for smaller residential applications due to their compactness and lack of moving parts.

Energy Wall™ is the first product that can successfully operate as a single core, replacing existing plate type exchangers - OR as a modular "energy wall", replacing rotary wheel exchangers.