Heat Recovery Ventilators are also known as air to air exchangers. In tightly built homes the air can become very stale and saturated with moisture just from occupants in the house. A tightly built home is great for energy conservation but can have poor air quality. HRV’s exchange the air in a house by using the pre-existing or dedicated ducting system. To reduce energy costs associated with exchanging indoor warm air with cold outdoor air, the unit uses a heat transfer core that transfers the heat from the exiting warm stale air to the entering cold fresh air. This is also an effective way of controlling moisture in the home.