# Questions On Adding A Second Ac Unit.



## cmykpro (May 12, 2015)

Hello all, we are the proud owners of a new 312bh. We used the unit this past weekend when temps were averaging 87 during the day. Our unit has one AC and it was difficult keeping it 75. The front bedroom seemed to stay the coolest with the door closed while the bunkhouse stayed much warmer. We tried opening the internal doors and keeping them open with little change. I'm thinking about adding a second A/C unit as we were told our unit was pre-wired for a second. Correct me if i'm wrong but I have gathered that the second unit is supposed to go in place of the skylight in the front bedroom. My concern is that the front bedroom is already the coolest place in the camper with the ac on. If I do add a second unit do the share the same ducting effectively pushing more air through the entire unit or does the ductwork to the front bedroom get cut off so the main unit cools the main cabin and bunkhouse?

Also if I do get a second unit does the main thermostat control both units or will the second unit be controlled independently by switches on the unit itself?

I know I want to add the second unit so if you folks know anything I may be missing or not properly understanding I would appreciate some good info. Also, if there are any specific model recommendations I would appreciate that as well.

Thanks a bunch!


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## cmykpro (May 12, 2015)

ob277rl said:


> Cmykpro there are a lot of things I could say about the way the A/C's are sized and setup in Outback's, but the simplest solutions would be to install the second A/C. The second A/C does go in the skylight and the power to be used for it should be right next to the skylight. The bedroom A/C will be a standalone unit and will not connect to the main A/C. The bedroom A/C can come with the controls on the unit or you can select a model that takes advantage of a wall thermostat (more expensive and complicated). When running the bedroom A/C you could close off the outlet in that area which would require you to change out the register in the bedroom to one that is closeable but that isn't necessary. Leaving the register open will help to take some of the cold air in the bedroom to the rest of the trailer due to the return air on the main A/C. To get more air and better coverage in your trailer install additional ceiling outlets, this would help in the bunk area. Good Luck.
> 
> Robert


Very good info, thank you. I just got finished talking with my dealer and he also said it should use a stand alone unit. I just find this strange since the room is already ducted from the main unit. To me it would make more sense to tie into the ducted lines already there which I would assume would increase the cool air flow all over the trailer. Perhaps two units on the same line work against each other?


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## cmykpro (May 12, 2015)

Well the plot thickens. I decided to call Keystone direct and talked with a service liaison. He actually said to get a ducted unit and a new dual zone thermostat. However when I asked if there was wiring in place for the thermostat already he was unsure.

I'm really on the fence here. On one hand I feel ducted is a better option as it will disperse the air more efficiently to the whole camper utilizing the ducts already in place. Since the bunkhouse tends to be the least cool area I think having two units push air back there might be for the best. However if I have to get a new thermostat and possibly run wiring from new thermostat to ne a/c unit it may be more work than I want to tackle.

On the other hand a second stand alone unit would be easier to install, cheaper, and not require a new thermostat and wiring. However if I went this route I would have to figure out how to block off the duct work in that room and hope the other unit will have sufficient cooling power to cool the main cabin and the bunkhouse.

So here I sit with the dealer saying one thing and the manufacturer saying the complete opposite, fun....


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## Texas Friends (Feb 12, 2006)

I added a second A/C unit to my Outback 5th Wheel and it is only wired for 30 amp service. The new unit "stand alone" is not tied into the ducting system. Our stand alone unit has made a DRAMATIC difference in cooling in the summer. Since the unit is not ducted the cold air blows directly into the RV instead of running thru the ducts that are heated up from the summer sun. The added unit is in master bedroom so we close the original A/C vents that run into that area.

We do not have it running thru a thermostat either... We just control it directly from the A/C unit and it works out fine!

*We have no problem chilling down the camper even in the hot Texas summers!*


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