Maybe this is just a silly non-pro question, but...
balance the returns, balance the returns... That's all you hear when talking about non-zoned systems. However, my HVAC installer is telling me that on our new zoned system the returns (at least one in every room with a door except bath and laundry) should always stay active regardless of whether the zone is calling or not. To me this makes no sense. In the non-zoned world the reasons for returns everywhere is to make sure you don't over pressurize any area of the house, right? Wouldn't pulling air from a return in a closed room, with no air going into it create a slight depressurization?
What is the correct way to do zoned returns?
Thanks as always.