We have 2 AC's in our 330RSTS and the one in the LR is the whisper quiet setup where the one in the bedroom has the removable ceiling panel to access the bottom of the AC with it's own "chill" vents that can be opened to allow direct air flow, or closed to use the helix ductwork in the ceiling. We were told from day one, not only from the salesmen, but Jayco (during a chat with a rep), and many others that already owned the same model, that the two AC's are ducted together and were designed to work in tandem.
After using the AC a few times, I noticed two separate things about the air flow from the AC ceiling vents. First was that the bedroom AC ceiling vents didn't have nearly the air flow that the LR ones did when running the corresponding AC units. So I pulled the ceiling panel from the bedroom AC and immediately saw where the holes were cut (or should I say "punched") thru the insulation board on each side to allow cooled air into the helix duct work. However, the holes were woefully small compared to the cutout in the AC unit itself and the ductwork, about the size of baseball. So I trimmed away the excess so that the hole matched the rectangular hole on the AC unit and duct taped the edges between the AC unit and the helix ductwork to seal it up. The airflow out of the two BR ceiling vents was now equal to or even a little better than the LR ducts were.
The second issue I noticed from day one, regardless whether one or both of the AC's were running at the time, was that the air flow to the camp side row of ceiling vents always had MUCH more airflow than the driver side vents did. From my experience with the BR vents, and seeing how things are attached to the duct work, my suspicion is that the same issue of a woefully small hole, or more likely, one hole smaller than the other was "punched" thru the insulation board on the LR AC unit, or that there was another issue that was allowing substantial air loss on that side of the duct work. But because that AC unit is inaccessible thru the LR ceiling due to the whisper quiet setup, I didn't know how to look for that, or any other possible issues and decided to add it to my punch list of issues and leave it until we took it in for warranty work. It worked ok for now, but wasn't where I felt it should be, especially after my experience with the BR AC install.
When we picked up the unit a few weeks ago and were going over the repairs that were completed, they mentioned they "fixed" the AC air flow issue. They mentioned something about air loss thru the BR AC and that the system was just pushing all the cold air OUT thru the BR AC! Not wanting to get into a lengthy discussion or otherwise "lose my cool" (pun intended), I moved on with the rest of the repairs.
So when I got the unit back home, I immediately took a look at what they did. Their "fix" was to just tape off the holes to the helix duct work in the BR AC unit that I had previously trimmed out to INCREASE air flow from that unit into the ceiling vents, and opened up the BR AC "chill" vents in the ceiling panel! So now, the LR AC was the ONLY unit feeding the helix duct work and opened up the "chill" vents on the BR ceiling panel!
I removed the "fix" and put it back to the way it should be for now until I figure out if there is anything else I can do to fix it myself.
Since then, I have noticed another possible contributor to my ills when I pulled the LR ceiling vent cowl. I have a lot of cooled air flowing between the ceiling insulation and the ceiling panels which means there is a pretty substantial leak somewhere. I have already found posts that recommend to pull all the ceiling vents and sealing the gap between the ductwork and the ceiling panels to prevent as much air loss as I can around those vents, and plan to do that shortly.
But can anyone suggest anything else I might be able to check out/repair on my own to address additional air leaks?