I just received shipment of a couple of new Coleman Mach 15 units to add to my toyhauler fifth wheel, one for the front bedroom and one for the garage. And I'm replacing and updating the ducted unit in the next couple of weeks. My Jayco is a 2005 model and I've been having to work on the main unit now fairly often.Other than wiring the garage unit on a dedicated exterior circuit that install is fairly straight forward although I need to figure out if I can use the wires that went to the vent fan to add a thermostat since that unit will be too high to reach the controls on without a ladder.But my concern is the bedroom unit. The roof over the front bedroom slopes towards the front end of the RV. Using a four foot level I measure a drop of two and a half inches. Reading the instructions for the Coleman unit it warns that the front of the unit needs to be higher than the rear if not level and if the roof is sloped in the wrong direction I should build a leveling frame to fix the problem. But I don't really want the unit to be sitting up off the roof. That will make wheather sealing a problem and it will be a place for leaves and trash to collect under the unit. Coleman advises not to mount the unit backwards for some reason, maybe to protect the coils while traveling.Has anyone else run into the situation and worked out a solution? I'm tempted to simply flush mount it and ignore the instructions rather than having it jutting up out of the roof that much. But I don't want condensation dripping back into the unit either.

You are talking about raising the low end 2 1/2 in. The high end won't be raised at all.

Not sure of the exact slope, but our front A/C is on a downward slope to the front of the rig.

I've seen lots of them on steep angled roofs like the transition slop between the lower and upper living area so they must be built to do it.

I see them on a slope too. I'm just going to flush mount it the same way I see all the others done.

The only issue that I see is possibly the ability of the unit to drain. Some have pumps and some use gravity, but the drain hole location could be a problem with either one.If the condensate pan were to overflow, you could get water in the electrics or even inside your RV.

Air Conditioning Leveling on Install | Good Sam Community

K_Charles
Explorer
Jul 04, 2013
You are talking about raising the low end 2 1/2 in. The high end won't be raised at all.
wkswenson
Explorer
Jul 04, 2013
Not sure of the exact slope, but our front A/C is on a downward slope to the front of the rig.
ScottG
Nomad
Jul 04, 2013
I've seen lots of them on steep angled roofs like the transition slop between the lower and upper living area so they must be built to do it.
boiledcrabs
Explorer
Jul 04, 2013
I see them on a slope too. I'm just going to flush mount it the same way I see all the others done.
haddy1
Explorer
Jul 04, 2013
The only issue that I see is possibly the ability of the unit to drain. Some have pumps and some use gravity, but the drain hole location could be a problem with either one.

If the condensate pan were to overflow, you could get water in the electrics or even inside your RV.
boiledcrabs
Explorer
Jul 05, 2013
I thought about the drainage. And I've watched it with the cover off. It seems to work fine. It is draining ok. I don't really see what difference the front to rear slope makes. Hopefully I won't find out later I was wrong but for now it's working great. Now to replace the main unit and add the unit to the garage.
RoyB
Explorer II
Jul 05, 2013
We always park our trailer with the back side of the trailer just down a bit to allow the air conditioner draining to go off the back side of the trailer instead of the front side awning area...

Roy Ken
Hornnumb2
Explorer
Jul 05, 2013
I think I would slope it on my bench and give it some power and see what it does before cutting hole for it.
stuplich
Explorer
Jul 06, 2013
boiledcrabs wrote:
I see them on a slope too. I'm just going to flush mount it the same way I see all the others done.

Why on earth would you mount an expensive roof air contrary to the manufactures instructions?
As Mom used to say, "if your friends jumped off a cliff would you think it was a good idea and follow them"?

But it is your money.... waste however you want to!
Mel
robsouth
Explorer II
Jul 07, 2013
Why not call Coleman and ask them about it. They may already have a solution so you don't have to reinvent the wheel. Worth a shot.