Dometic Air conditioner / Themostat

[rohrmann]

It's probably doing the best that it can with only one A/C. You might have better results if you had a second A/C, and this doesn't have anything to do with the way the A/C is ducted. Your rig is 35 feet long and you not only have to cool the air inside, but also everything inside, walls, floors, furniture, etc. That is why it is suggested to have the A/C(s) on early, so it doesn't warm up inside.