[mtlakejim]

You folks lay off of the OP. He has a real issue that is VERY common to Keystone products. He should be praised for bringing up the issue not belittled! The OP is correct that these campers are rather expensive and at the very least you would EXPECT systems to function as they should even if they don't use the best quality trim and such. There are places to use less expensive materials to give a lower cost and places here you should NOT cut corners!


Now to the issue. Yes this is a very common problem with the so called "quiet air" systems. As an engineer I am calling it out for what it is a DESIGN FLAW! The materials and design of those return ducts was not fully thought out PERIOD!! Keystone has admitted as much by coming up with their new "rigid duct" system that amounts to a band aid hard plastic connector between the duct sections (there are even videos of so called professional RV reviewers praising the rigid ducts--ya think they might be on someone's payroll?).


The owner developed solution is simply to stick two short lengths of 1.25" pvc (cut just small enough to fit thru grill holes), turn them parallel to the vent and slide them about half way between AC and the grill. That will effectively keep the cheap cereal box vent open. In addition most folks remove, replace or modify the outlet vents to increase air flow as well. You will find this resolves the issue.


However be advised that the very best you will get out of two AC units is a 20F drop from outside temp. If you add a third AC and set it up where you can run all 3 then you can get about 25-27F difference. We live in the desert so we know EXACTLY what you can get out of them best case (of course that is in low humidity but no shade).


Good luck and best wishes!