Adding second A/C unit

[Matt.Bud]

Hi all,

New member here, so I apologize if this is posted in the wrong spot. I tried searching the forums and didn't find much on what I'm looking into. I'm wanting to install a second A/C unit on my fifth wheel. If I understand correctly, the second unit will replace the roof vent in the master bedroom and should fit in the hole that's already there (correct me if I'm wrong). It would be a ductless unit with temperature controls right on the unit itself. First, any suggestions on which unit to use would be great, as I've just started to research them. Second, I'm looking for some model-specific info. My camper is a 2017 Wildwood Heritage Glen 356QB, I'm wondering if anyone happens to know off-hand if it would be pre-wired for a second A/C unit? I'm guessing I could look in the breaker box to see if there's a breaker dedicated to another A/C circuit, but my camper is currently being stored 3 hours from me so I can't just go check it out. Also, if it should be pre-wired for the second unit, does anyone know where the wiring would be located? I would expect it to be somewhere around the vent hole in the master bedroom, but I have no experience and that's just a guess.

Any help/guidance would be greatly appreciated!

[A32Deuce]

Is your unit 50 amp? If so, it may be pre wired for an A/C unit at that vent. Pull down the surround and check. The 120 volt wire may be there. I know some units come that way.

[Matt.Bud]

Yes it's 50 amp. I'll have to pull down the vent surround and check when I go get it in a couple months. I hope it's already wired, that would save a lot of work. Thanks for the tip!

[Larry0071]

I can not speak to your unit make/model, so take this for what it is....


I had my bedroom vent replaced with a fantastic fan and the shop that I had do the job mentioned to me that I had both 12V and 110V wiring in place on the edge of that vent hole. Once they removed the vent/crank assembly, folded up at the edge of the cut out was the wires needed for a fan or an AC unit. I do not show an extra AC breaker, so my assumption is that they must have that set of wires for the 110V hanging out back behind the panel someplace? I would guess further (and trust me, I am no electrician!) that the wires would need to be placed into a new breaker dedicated to that set of wires.


So depending on the responses or lack of responses that you get, you may want to start out by pulling apart that OEM fixture to gain visual access to the surrounding area and look for the wires that were seen in my Coachmen Apex unit. That would at least tell you that this was going to a fairly easy endeavor compared to pulling wire to create your own circuit.


I wish you the best and hope that you get informed responses to your specific unit.


Happy New Year!

[llr]

My TT was available with a 50AMP option or a 50AMP & 2nd air prep so unless you know the details on what was available on yours and what it has it is hard to say.

It could have been standard or an option.

[Bama Rambler]

According to the spec sheet for that model it has wiring and bracing for the second A/C, so looks like you're in luck.

They do the wiring in a couple of ways. There is supposed to be a box mounted in the ceiling near the cutout with a blank cover on it that you would run wiring from it to the A/C, but a lot of times they just terminate the wiring with wire nuts and leave it in the ceiling near the hole. There is also supposed to be a breaker for it, but again, a lot of times the wiring is just rolled up inside the power center.

[Matt.Bud]

That's what I wanted to hear Bama, thank you! I can handle adding a breaker and connecting the wiring if it's already there. I was NOT looking forward to having to run new wiring, so you've given me hope that it should be a fairly easy install. Again, thank you!

[LedgendarySharp]

Hey I’m doing the same thing to my 2012 Forest River Wildcat. I did find a YouTube video showing an installation. Just type adding second AC to RV. You should be pre-wired if your unit is a 50Amp. I did say should be! My was pre-wired but my wires where under a solid light switch cover next to vent opening in bedroom. You mentioned you wanted to go ductless and use controls on unit only. I’m doing the same thing but think it through. If you do that you have to think about these units only lower the outside temperature about 25 to 30 degrees at best. So if you visit hot location a ducted unit will help cool the hold unit. I like the Furrion 15,500 it cools better and is the quietest. Domestic is what I have living area. Very loud! Go etrailer.com for a good review for different AC’s before you choose. The hardest thing is going to be getting up on the roof.

[Matt.Bud]

You bring up a good point, I was leaning towards non-ducted simply because it should be easier to install. If I wanted to add a ducted unit for the second one, would it be as simple as tapping into the ducts that are already in the ceiling in the bedroom? (again, I'm looking to install the second unit in the current ceiling vent hole in the front bedroom). If so I'm guessing I'd have to pull down some ceiling panels to access the existing ducts (haven't paid too much attention to what would be involved with taking down some of the ceiling, but I can't imagine it would be too terribly hard).

I like the idea of having the second unit ducted to help out the original unit, especially since it's a larger trailer. however, I was also just exploring the option of adding a thermostat in the bedroom connected to the second unit, and having the second unit only control the temp in that room. In which case I would block off the ducts in the ceiling coming from the first a/c unit, which in turn should increase flow out of the remaining ceiling vents throughout the rest of the camper. Just a thought, you've got me thinking now...

[RUcamping]

I have 2018 27RK Crusader Lite with 30 amp service. I have installed a Coleman-Mach 8 Cub Air Conditioner 9000 btu with heater in the front bedroom. I have also installed 2 EasyStart™ 364 (3-ton) Soft Starter in each A/C unit. Main A/C is a Brisk 15000 btu. Also have installed the Progressive Industries HW30C 30 Amp Hardwired EMS-HW30C RV Surge & Electrical Protector. I had to add in my own wiring to the breaker panel. With this installation it has allowed me to run both A/C units at the same time. I can also run the two A/C units on my Champion 3500 watt generator. Had to fabricate a bypass plug for the generator cause of the Progressive unit.

[justpassinthru]

I actually had dealer install a second ac for me in the exact spot, and was already prewired so a relief. It cost me a total of 1200$ including install and parts. If your capable to do the work even better. Only one concern in your post is. You want to install a unit that is non ducted with the controls on the interior of the ac I will give you a food for thought. 4 yrs ago I had a ac installed on another 5th well we had before and hated the controls on the ac to adjust temp and fan speeds. Reason hated was yes unit will cycle off at the temps you set at the dial but, the fan speeds are either low, Ned and high or off. Meaning all night long need to listen to fan running at selected speed. So on my 2020 unit I made sure ac was with a wall thermostat that way when it reached the set temp it shut off fan and ac together. Similar to your home ac. Just wanted to throw this out to you. I guess if you don’t mind that fan motor running day and night go with the ac with the controls. Or get one installed non ducted or ducted but make sure it’s on its own separate thermo. Also they ran thermostat wire from ac through ceiling and fished to wall for the thermostat. Also the one added on my 2020 5th wheel is a Coleman ac and Coleman thermostat vs those problematic thermostats by Dometic and there AC’s as well. Hope this helps. Good luck

[Kimber45]

as previously stated you can pull the vent and look for a wire. My heritage glen unit came with the second ac unit but my build sheet showed an option for pre wired. If you have your build sheet it would clearly say yes or no.

[Matt.Bud]

Thank you for the input! I was looking into the thermostat option and I think that's the route I'll go. Non-ducted with a thermostat just for that bedroom should work well, and as I stated earlier, I may block off the existing vents in the bedroom from the original A/C unit to hopefully increase airflow from the rest of the vents. Should work pretty good.

[5picker]

Originally Posted by Matt.Bud

Thank you for the input! I was looking into the thermostat option and I think that's the route I'll go. Non-ducted with a thermostat just for that bedroom should work well, and as I stated earlier, I may block off the existing vents in the bedroom from the original A/C unit to hopefully increase airflow from the rest of the vents. Should work pretty good.

This is what I did on a SOB (some other brand) I had.
The front A/C did much better at keeping the bedroom cool than the ducts from the rear A/C and the living room/kitchen cooled way better with only needing to cool that area.

I simply blocked the vent ducts by pulling the last two vents in the ceiling towards the bedroom and used foil tape to seal them closed inside the duct. Reinstalled the vents and wala!

[Matt.Bud]

That's what I like to hear! Thank you for your input everyone!

[psb retired]

i added one to my tt,i choose a colman mach 8 ps [power saver]it is 13,500 btu but only draws 10 fla including the blower,i choose this one so I could run it on 1 2000 generator,i though about the 9000 btu model but want to chance it not being big enough on 100 degree days,my tt was not set up for 2nd unit so I had to do all the wiring and add roof support,it is non ducted little loud but we can still sleep,only have to run it on low speed,left existing vents connected for night when we don't need 2nd a/c,hope this helps

[dannybye]

If you are really lucky like my self. You'll love Forest River.

1st when I took the trim ring down there were three sets of wires. 1st for the temperature sensor that has a sticker on the bedroom wall saying ac sensor. 2nd was the 120 hot wire and 3rd a harness that goes back to the dual unit thermostat. Choose which unit to set then go to the 2nd one. As for ducting in the ceiling was a cutout where a duplex plug box was cut into the insulation. Took that out and with the AC running air is coming out out of the hole. Checked the other side in the white styrofoam insulation. Sure enough poke a hole and air comes out there. So bottom line when my install is finished it will be just like I ordered with dual 15k air-condition units. Ducted and controlled from one thermostat.

Good luck

[Red Wolf]

I just purchased a Coleman Mach 10-NDQ (non-ducted, quiet). 13,000 BTU, ~10amp draw. I'll be placing it at the rear vent of our 5th wheel (kitchen).


Only having a 30amp unit, there is no additional wiring. I'll route wiring through the ceiling to the top of the fridge cabinetry, then left through the top of the closet, down to the floor inside the pantry, and out the back side of the trailer via waterproof 15amp socket.

Unfortunately, I'm going to need to push in the thin paneling that closes off the hollow above the fridge in order to get romex cable out of the ceiling and into the cabinetry, and I'm not sure how to close it back up afterwards.

[Kimber45]

do you have the build sheet for your unit? my heritage glen came with two a/c units but the build sheet clearly shows being pre wired as an option with 50 amp units.

[cavie]

Originally Posted by Matt.Bud

Yes it's 50 amp. I'll have to pull down the vent surround and check when I go get it in a couple months. I hope it's already wired, that would save a lot of work. Thanks for the tip!

Look at your breaker box and see if you have an extra 20 amp breaker marked A/C. You can also remove the panel cover and see if there are any unused wires inside.