I'm not an HVAC expert by any stretch of the imagination, but I'd think that all vents need to be within the same zone/floor that the return(s) for that zone are located in.

After we moved into our new home, I realized that the foyer vent and an upstairs bedroom vent were switched. The HVAC guy came back and switched the ducts, which were right next to each other and still accessible in a part of the lower level ceiling where we were going to put up a DIY dropped ceiling. If they'd been in a different location, he would have had to tear out the drywalled ceiling. He said mistakes like that occasionally happen.

What you've got will give you more a.c. in the summer and more heat in the winter in the first floor rooms, and less in the 2nd floor rooms. To me that would not be a good thing, since the 2nd floor zone goes on much more often during both seasons than the 1st floor zone, and therefore without those 2 ducts up there the affected rooms probably would be hotter in the summer and colder in the winter. How the various 2nd floor rooms would be affected would depend on where the thermostat is, and how well the air is circulated throughout the house.

However, it may not be that the ducts are switched. They may have forgotten to do whatever they need to to switch the duct to the 2nd floor zone--there's some little mechanical thingy that they add to the duct. But they'd have to be able to access the ducts.

Anne

Thanks, I guess I'll mention it and see what they say.

Bee