Our Fifth Wheel only came with one AC, that is thermostat controlled. Needless to say, it's not powerful enough on it's own to keep this place cool during Texas summers.I've watched some videos online about installing a second AC. It would not matter to me if it hooked into the existing ducts or not. What I have seen is that you can put them in place of an existing skylight.In the main bedroom of the coach, we have a skylight right above the bed. However, when you view it from the topside, looks rather close to the front edge of the coach. Would we still be o.k. to install one, like for example, a low profile one or would we need to move back some and cut a new hole in the roof? Thanks!

My 2c worth. All of the AC's that I have had installed or seen others install all go into the existing roof vent (which I believe is what you are referring to). What is most important is to make sure you have an electrical outlet beside the vent to accommodate the AC installation. This pre-wire should also give the required electrical fuse/tripper in your fuse box. Personally I would have it professionally installed vs. a DIY job. GPG :-)

Look next to that bedroom vent/skylight and see if there is something that looks like a blank cover for an electrical box. Remove that cover and see if there are electrical wires there. If so, you are probably good to go for electrical connections. If no existing wires I don't know how you would ever get them there.

..........You might also consider an inside unit that exhausts the hot air out through an existing window ! They come in several sizes , but I wouldn't buy anything less than a 12,000 btu. The cheapest way is to simply install a window unit if it will fit into any of your exist openings . A place called Air and Water sells several brands of the inside units , they will run from 400 to 600 depending . , jf

If there is a breaker in the breaker box labeled 2nd AC then you will have an easy job. The wire for the 2nd AC will be in the area of the bedroom roof vent. It could be in a electric box with a blank cover on it or it could be like mine, when you remove the trim for the roof vent you will see it. Remove the roof vent. The AC will sit over the hole. The hardest part is getting the AC unit on the roof.

Are you sure you want an A/C above the bed? That's white noise to the extreme!

Questions on installing second AC | Good Sam Community

26 Replies

WrightOn
Explorer II
Aug 07, 2016
I'm in the process of purchasing and wiring it so that I can plug right into a 20A post. For those who have done this, can you post some pictures for ideas, please?
zackyboy3rs
Explorer
Jul 31, 2016
MO_Trout_Bum wrote:
zackyboy3rs wrote:
I did not install our 2nd AC but it was the best $900 I have spent. Extreme heat here in eastern NC and it was never uncomfortable in our 5th wheel.

Same here. $1000 well spent on a Domestic 15.5k unit. We also don't mind the white noise at all. I sleep like a ton of bricks in our Fiver.

Also, I was told it would be a non-ducted unit but they were able to tie it into our "whisper quiet" AC so it is ducted. Still loud but I am COOL!
MO_Trout_Bum
Explorer
Jul 31, 2016
zackyboy3rs wrote:
I did not install our 2nd AC but it was the best $900 I have spent. Extreme heat here in eastern NC and it was never uncomfortable in our 5th wheel.

Same here. $1000 well spent on a Domestic 15.5k unit. We also don't mind the white noise at all. I sleep like a ton of bricks in our Fiver.
Whiskey_River
Explorer
Jul 29, 2016
OK, thanks for that BarneyS. I did not know anything about a portable A/C, only that air conditioners usually have water from the excess condensation on the evaporator coil, unless running somewhere with no humidity in the air. Interesting that it is blown out thru the exhaust process.
crcr, The a/c I installed, a 13,500btu non ducted Dometic weighs 72# per their spec sheet. I think the 15,000btu unit weighs 74#. Once you get it on the roof, one person can move it around and set it over the 14" x 14" vent hole.
crcr
Explorer
Jul 29, 2016
How much do these RV air conditioners weigh?

If I ever have occasion to install one, I have a chain hoist that I would probably secure to the eave of my house to hoist the AC onto the RV roof.
zackyboy3rs
Explorer
Jul 28, 2016
I did not install our 2nd AC but it was the best $900 I have spent. Extreme heat here in eastern NC and it was never uncomfortable in our 5th wheel.
brirene
Explorer
Jul 28, 2016
Retired JSO wrote:
I installed a second unit in a fiver I had back in 2005 a 30 amp Sandpiper. I used the existing vent above the bed. I was able to run a wire through the ceiling from that area toward the door side to a closet. There I installed a small GE breaker box which I used to run some additional outlets. I continued down into the basement and ended the wire on the curb side with a flush mount male receptacle. Used a short 12 gauge extension to the 20 amp in the post.

That's the one I've been waiting for. If I was to add a second unit, that's the way I'd do it.
Retired_JSO
Explorer
Jul 27, 2016
I installed a second unit in a fiver I had back in 2005 a 30 amp Sandpiper. I used the existing vent above the bed. I was able to run a wire through the ceiling from that area toward the door side to a closet. There I installed a small GE breaker box which I used to run some additional outlets. I continued down into the basement and ended the wire on the curb side with a flush mount male receptacle. Used a short 12 gauge extension to the 20 amp in the post.
BarneyS
Explorer III
Jul 26, 2016
I just sent him a text message with some of your questions. Will post his answers just as soon as they come back. :)
Barney

Edit: Here is his answer.
12,000btu unit

cost $280 at Costco

There is no water collected. It is exhausted out of the RV with the exhaust airflow.

Installation is simple as fitting the exhaust to a window.

It is rated at 9.6amps so he runs it off a separate extension cord to an outside circuit.
Barney
Whiskey_River
Explorer
Jul 26, 2016
BarneyS that looks like an easy install for a quick fix.
Just wondering, what happens to the condensation. Did he drill a hole in the floor to run a line, or does the unit catch the water like a dehumidifier, then shut off when full if there is no discharge line?? No at all familiar with that type of mobile unit.