[Jack Houpe]

The basement air looks like it has been modded to me. Is that where your existing heat pump/AC outside units are? Because the original SCS units were NOT heat pump capable. If Newell retrofit the new units into that space, which would be logical, then some modification was need to adapt the conditioned air outlet into the existing ductwork.

The discharge outlet on the SCS units was on the very top, and one elephant snorkel was attached at the top. That snorkel fed the internal distribution system. The front ductwork was very simple, it divided into two flexible hoses that ran up the passenger wall with the discharges just above the passenger head and just above the door. The rear setup was a lot more convoluted depending on the floor plan of the coach. Usually there was one plenum that ran the centerline of the basement and split into ductwork for the galley, bedroom, and bathroom(s).

The air intake was underneath the steps and fed a central cavity that both SCS units pulled recirculated air.

Some of what I described is a bit different with ‘race’ coaches. Some of them had both SCS units mounted on the driver side to move the noise away from the passenger outside area.

These are Coleman model #46515-811 two ton basement heat pumps, they are probably OK if hooked up correctly but they are not plumbed into the system in a good way and the heat pump doesn't work on either unit and if they did in the past there is something wrong and I suspect it has to do with thermostat wiring. Discharge air from what I can tell is on the bottom but I will verify that soon. To much silicon rubber and hvac tape to make joints. 

The mini splits will be a vast improvement over this situation and a lot cleaner mechanically.