The next rumor I tracked down concerned the Zehnder ComfoBox, a combination appliance that includes a ground-source heat pump, hydronic heat distribution system, domestic water heater, and HRV. Zehnder's U.S. representative is Barry …. Ventilation requires small air flows, while the delivery of space heat and cooling usually requires larger air flows — making the integration of these two functions illogical. In hopes of achieving a particular heat-delivery goal, …