This is the Zehnder HRV (Heat Recovery Ventilator) Unit that we just installed in our Passive House off the Palouse. These systems first came to the U.S. in 2010 from Germany where Passiv Haus construction originated. HRV systems transfer heat or coolness from stale exhaust air to fresh intake air. This balanced ventilation system removes excess moisture, odors, and contaminants while conserving energy and enhancing comfort. This is really cool technology. Read more about it at ZenderAmerica.com.