A stand-alone recovery ventilator pulls in fresh outdoor air while exhausting stale indoor air. The air streams pass through opposite sides of an exchanger core. Ideally, the two air streams do not mix at all but do exchange heat (both ERV and HRV) and moisture (ERV only). In winter, then, the outgoing warm air gives up some of its heat to the incoming cold air. The warm air also has more moisture and in an ERV, some of that moisture will migrate to the cold, dry air coming into the house. Illustration by Tim Healey.
As a stand-alone system, it needs it's own duct system. The lines can be smaller than heating and cooling ducts, which makes them easier to snake through the house. These lines are made by Air Pahoda. Photo by Ted Cushman.
This metal manifold, supplied by Air Pohoda, will serve as the return manifold. This manifold lacks any sound attenuation characteristics, but the designers considered it adequate for the return lines of the system. For the higher-velocity supply-side air, the designers on this project chose a Zehnder manifold with sound-attenuating mass-loaded vinyl core elements. Photo by Ted Cushman.
An air supply register in the ceiling. Each register can be served by either one or two three-inch lines, depending on the quantity of air needed. The system is fine-tuned by adjusting manifolds and fan speeds, and can be modulated as needed in service to respond to changes in the required exhaust and supply rates. Photo by Ted Cushman.
An alternative wall-mounted supply air register on a different project. This register and the line are made by Zehnder. Photo by Tim Healey.
Ceiling mounted supply were installed in the bedrooms. Photo by Tim Healey.
Eric Hartman of Harvestar, in Lincoln, Vt., gets ready to install the grille on the ERV exhaust outlet. The fresh-air intake is behind him. The manufacturer (and building codes) require that the outdoor air intake and exhaust air grilles be located a minimum of 10 feet from each other