One of the features of the Highland project will be a whole-house Heat Recovery Ventilator (HRV) system. Unlike a typical heating and air conditioning system, which recirculates air within the home, an HRV is a distinct system designed to continuously bring fresh air into the home and exhaust stale are. That’s the “ventilation” part. The “heat recovery” part refers to a heat exchanger where energy is transferred between the incoming and outgoing air streams. For example, in winter, cold air is brought into the HRV from outside and the warm exhaust air is used to pre-heat the cold fresh air before it is introduced into the house. Similarly, in summer the relatively colder indoor air is used to cool the incoming hot and humid air. Thus the HRV supplies fresh air but also reduces the home’s energy use, since less heating or cooling is necessary to condition the fresh air. One major HRV manufacturer, Zehnder, has an interesting article about the need for mechanical ventilation in efficient homes
