I have had my 282DBHS for just under a year. Last year we did not use the AC much and I thought it was working fine. It wasn't until a trip over July 4 that I realized I was wrong. After removing the interior panel I found that there are two ducts that come out of the AC unit. One feeds the camp side and only runs into the bathroom. The other (non-camp side) feeds four vents that run the entire length of the camper. There was very little air flow out of the vent above the rear bunk and just moderately more out of the remaining vents. The vent in the bathroom blows air like a jet engine.
I took off all of the vents and taped them so the air feed from the duct into the vent and not into the ceiling. Like everyone else with Dutchmen products, the vent installations were done by a blind person (no offense to the blind).
That still did not produce any real changes so I lowered the interior portion of the AC unit. I discovered that the feed to the bathroom vent was 2X6 and the feed to the rest of the camper was 2X2. I tried taping off some of the bathroom vent but the that restricted airflow too much causing the unit to shut off. I called Advent and they sent me a new freeze sensor.
After looking at it again I decided to try and make the opening on the non-camp side bigger. I removed all of the foil tape on that side and discovered that the feed into the duct was in the wrong spot (about 5 inches off) and that was why the opening was so small.
Main duct feed
I could not move it so I was able to make a rectangle "duct" out of some foam I had around the house. I then cut the existing duct and inserted it into place. Then I taped everything off making a much larger opening than previously existed.
I then made the opening to the bathroom duct a little smaller as well.