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Re: 2nd ac Unit

Posted: April 29th, 2019, 9:20 pm
by Larrytbm
I'll add this, the Coleman unit, while fairly light, is physically very big. Something like 43" in length and most of that is behind the 14" roof vent. I had no clearance issues, but awkward to lift onto the roof. The instructions say the unit must be mounted level (when the RV is level) or max. 15 degrees low at the rear for proper cooling. This is fine if the unit is going at the rear of a fifth wheel. But the entire value of a low profile unit is where the fifth wheel has it's highest point at the front of the RV. And that means the roof is likely sloping down at the front, which is the case with the Telluride. Anyway, I used solid PVC trim from Lowes to make a 14" x 14" base that was 3/4" thick at the back and 1-1/2" thick at the front. That makes the unit sit level on the sloped roof.

On the other hand, since doing my installation, I have seen a Jayco Eagle with the same Coleman unit for the 2nd A/C. It was clearly sloping down at the front, so not consistent with Coleman's instructions. And it was probably a factory installation. Just FYI

Re: 2nd ac Unit

Posted: April 29th, 2019, 2:07 pm
by neversweat
Thanks Larry, great info and confirms what I was thinking.
Getting a few quotes now on the Coleman Mach 8 low profile unit.
Most want to match the Dometic unit that I have but I have seen on the web that the low profile unit can be loud.
This forum seems hard to move around in, especially on the phone, or maybe I just need some practice!
Thanks again,
Bill
http://www.starcraftowners.com/posting. ... =30&t=3062

Re: 2nd ac Unit

Posted: April 17th, 2019, 3:02 am
by Larrytbm
The standard thermostat only controls a single A/C unit, it is not a dual zone model. Also, there are no thermostat wires running from it up to the bedroom vent. So the 2nd A/C needs it's own thermostat and wiring to connect to the A/C. Much easier to use a unit that has the thermostat built into the A/C unit, which typically means a non-ducted model. The low profile unit I bought had mounting bolts that were way too short for the thickness of the roof. So, I had to use all-thread rod cut to length and double nutted. I think the bolts were 6" long and I needed at least 8", but I can't remember for sure.

2nd ac Unit

Posted: April 14th, 2019, 7:34 pm
by neversweat
thinking of adding a 2nd ac in the bedroom. Larry has mentioned he has done this,anyone else? Curious if I should tie into the ducted system or keep it as a stand alone unit. If tie into the duct work will the same thermostat work for both unit or will I need to add one? Have not taken the vent out to see what there, yet, and the dealer I don’t think knows either.
Any input would be appreciated!
Thanks
Bill