Connecting Bedroom AC to Main

[meaz93*]

Wondering how big a job it would be to marry the bedroom AC to the main plumbing?
I have a 2018 Outback 328RL.
(2) Coleman Mach 13.5 AC's....not sure why it didnt come from the factory with the main unit housing a 15k, especially since it shipped to AZ.
Anyway it doesn't make much sense to me not to have the bedroom unit working in conjunction with the main.
Their is 1 AC outlet in the bedroom ceiling. Take it in and have it professionally done or is it a somewhat straight forward repair?
PS....yes I currently do the oscillating fan in the bedroom pointing to the main room with changed out adjustable/closing vents in the bathroom & master bedroom to help out.

[sourdough]

Are you talking about trying to run them off the same thermostat? Do they both share the same ductwork or is the bedroom unit a stand alone? Do you have InCommand? Trying to let a thermostat in the living room control the temp in the bedroom is probably going to lead to some aggravation due to the variance in temps.

[wiredgeorge]

Do you own a sawzall? If you have interconnecting ducting (take out fan and look) and you have a thermostat that has 2 zones, probably not a big deal. If not, welllll get out the sawzall.

[meaz93*]

@sourdough & @wiredgeorge .....the sawsall> now that's funny![emoji6], although I do own a Milwaukee [emoji106]
I do not have dual zone thermostats....just changed out the Colemans to digital.
The bedroom is plumbed for blasting and or for a huge hairdryer? None the less you could hang beef in their> a good thing : blush:
I called a RV service Tech and actually found one that was pretty knowledgeable...yeah suprised me too.
It sounds like it could be " Rocket Science"... maybe it can be done, maybe not...bring it in we'll look it over kinda thing.
It's also possible that that bedroom AC could cause some turbulence like Sourdough mentioned.....
I also was told that since I'm in AZ having a 15k vs a 13.5k AC unit wouldn't make a whole lot of difference?>ok[emoji848]
Sounds like a lot of work...

[sourdough]

Being in Phoenix every bit of A/C you can get will be important. I've looked and looked and the best I can tell is that your primary unit is ducted. The optional bedroom unit is wired but that's it leaving you with a manual overhead unit like you describe - and yes, that bedroom A/C, even at 13.5k will run you out when using the dump.

When I installed the 2nd unit on my last trailer I asked about ducting (which it didn't have either) and was told it would be very hard, very expensive and maybe impossible due to trying to get through the roof rafters (aluminum) with ducting. I opted to forego that effort and expense and live with it. We let the main unit (ducted) take care of cooling chores until we hit hot country. In addition to the Reflectix etc. I used the bedroom unit on max cool/high fan with a 20" box fan pushing air into the main area. It worked pretty well. The fan was in the bedroom door and we had access through the bathroom to the bedroom.

[JRTJH]

There are two types of "roof ducting configurations" used in travel trailers. One, the first type used, is "S-configuration". It has two supply ducts on the A/C unit, blows air out both sides with the warm air intake on the bottom of the unit. One side of the supply ducting goes left and to the rear of the trailer, the other goes right and to the front of the trailer. (sides may be reversed in some models).

The other, more recent "innovative ducting system" is the "racetrack ducting system". It has one supply duct, usually on the right side of the main A/C unit and two return air ducts, One on the bottom of the unit and one on the left side of the unit. This configuration allows for air to be "drawn from the supply duct if "looped to the second air conditioner unit".

The two types are not interchangeable and attempting to "rebuild the ducting" would first require removal of most of the ceiling panels and "hopefully" the roof rafters that were installed have holes on both sides for ducts to pass through. If so, the system "could be reconfigured at great expense"... If the roof rafters do not have holes to fit the "racetrack ducting" then an entire "trailer roof structure rebuild" would be necessary... That's likely to cost more than the trailer is worth at this point, so for most people, it would not be a "sound financial venture"...

Short answer: From the information in the 2018 Outback brochure, your trailer has "S-type ducting" (first picture) and that configuration does not accommodate connecting both air conditioners to the same ducting system. You can see the difference in the second picture from the Laredo brochure.

[meaz93*]

@JRTJH ....thank you for saving me a wasted trip to the RV Dealership only to be told what you presented[emoji106]
I have 1 more mod to try out and that would be the RV AIRFLOW KIT .
I guess it can only help.

[wiredgeorge]

I installed an RV Airflow in my Dometic 15K btu A/C and it helps airflow quite a bit.