2004 Newmar Essex AC/Heat ductwork

[remi]

can anyone tell me if the heat / ac duct work in the ceiling and walls of this model have duct piping or is the ducting done with channels cut into the insulation?

[JFXG]

You have HVAC registers in your walls? I’ve never seen that. In my ‘02 DutchStar the output of the roof units — hot or cold— is distributed through a single continuous duct that runs through the length of the ceiling, with 8 or 9 outlet registers along the length. This is a tandem duct, the opposite side of which carries the return air.
The propane furnace is mounted at floor level, and this output is also carried through a single full-length duct in the floor with four registers along the length. There’s also a furnace output duct to the water bay. The furnace return is a simple louvered opening in the cabinetry at the furnace location.

[Luv2go]

As JFXG said, Newmar has used two equal sized rectangular ducts for A/C Heat Pump for a very long time.

007 has some information about the HVAC in his Quick Tips and Easy Mods (Look down the page to the 6th and 7th posts for them, search for "AC's & HEAT PUMPS & CONTROLS" in the first Quick Tips post).