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Replace existing AC or add 2nd unit in the bedroom

Vt_Rv
Explorer
Explorer
My air conditioner, although blowing cold, isn't cooling enough to keep up with the heat. I have a Coleman unit, not sure if it's 15000 or 13500 but think it's 13500.

I was debating on replacing with a new 15000 then realized that the rear vent in the bedroom is pre wired and vented to add a second AC unit.

Now I'm wondering if I should put in a new unit up front and move the old one to the rear.

Just add a second unit in the bedroom.

Or just replace the front AC.

I'm also wondering if this is a DIY job or if I should have it done. With it being pre wired with a connector and breaker And having it vented into the duct work will both units run off the existing thermostat?

I have 50 amp service so will I be able to run both at the same time and run off the generator? The generator is a 5500 with 50 amp service.
2003 Damon Challenger 348
2011 Ford F350 Diesel
2005 Harley Davidson Electra Glide Ultra Classic
So many toys, so little time! Retirement? Tick Tock, Tick Tock
20 REPLIES 20

Mile_High
Explorer
Explorer
The first time I added a 2nd AC, you just get the bottom diffuser trim with the controls and thermostat built in. There is no need to modify your original wall thermostat.
2013 Winnebago Itasca Meridian 42E
2013 Jeep Wrangler Unlimited Sahara Towed

nemo45
Explorer
Explorer
nemo45 wrote:
mpierce wrote:
I have a 90 Bluebird. The rear bedroom AC quit. The AC guy said the wiring and thermostat would need replacing too, as they are too obsolete for the newer ACs.
So, I put an Atwood AC in. It has a panel on it to control it, and it uses a remote. NO wiring, NO thermostat, just need the power feed.

Works great. More efficient that the oem too. That is what I would do. Nice to be able to lie in bed, and adjust the temp, turn off, etc. without getting up at 2AM!


This is really a good idea. I wish I would have put one in with a remote, and I think Dometic makes one too, as my wife is too short to reach the controls without a stool. We have 7-1/2 foot ceilings. So, anytime the A/C has to be turned on, off or adjusted I have to do it. Yes, I'm lazy. If I have to replace the other one that's what I'll do. Remember though, if you have a furnace running on the thermostat for the A/C It won't run without the A/C in the loop, because there is a 12V wire for the furnace that runs the A/C controller so they can't run at the same time. I had to put a manual thermostat for the furnace in. If you're just adding an A/C its not a problem.


Found out Dometic doesn't make one with a remote for the air box.
Don Niemeyer
2006 Gulf Stream Tour Master T40A
2011 Chevy Equinox LT1 Toad

mike_brez
Explorer
Explorer
falconbrother wrote:
Installing a roof AC is very easy, even the wiring is simple.. But, if your RV is a 30amp you don't have the power to run an extra AC unit. Two roof AC's are found on 50amp RVs. But, you could pull a second 15 amp circuit. I have done that an I ran a 15amp shore connection. Just be real comfy with your wiring and circuit breaker. For a second AC I chose an 11000 BTU and it was more than enough.

Seriously, the hardest part is getting the thing up there. I have done this job 4 times. If the wiring is there and you have the amps it's as easy as falling off of your RV, which you should avoid.


OP in his first post said he has a 50 amp service.
1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU

falconbrother
Explorer II
Explorer II
Installing a roof AC is very easy, even the wiring is simple.. But, if your RV is a 30amp you don't have the power to run an extra AC unit. Two roof AC's are found on 50amp RVs. But, you could pull a second 15 amp circuit. I have done that an I ran a 15amp shore connection. Just be real comfy with your wiring and circuit breaker. For a second AC I chose an 11000 BTU and it was more than enough.

Seriously, the hardest part is getting the thing up there. I have done this job 4 times. If the wiring is there and you have the amps it's as easy as falling off of your RV, which you should avoid.

nemo45
Explorer
Explorer
mpierce wrote:
I have a 90 Bluebird. The rear bedroom AC quit. The AC guy said the wiring and thermostat would need replacing too, as they are too obsolete for the newer ACs.
So, I put an Atwood AC in. It has a panel on it to control it, and it uses a remote. NO wiring, NO thermostat, just need the power feed.

Works great. More efficient that the oem too. That is what I would do. Nice to be able to lie in bed, and adjust the temp, turn off, etc. without getting up at 2AM!


This is really a good idea. I wish I would have put one in with a remote, and I think Dometic makes one too, as my wife is too short to reach the controls without a stool. We have 7-1/2 foot ceilings. So, anytime the A/C has to be turned on, off or adjusted I have to do it. Yes, I'm lazy. If I have to replace the other one that's what I'll do. Remember though, if you have a furnace running on the thermostat for the A/C It won't run without the A/C in the loop, because there is a 12V wire for the furnace that runs the A/C controller so they can't run at the same time. I had to put a manual thermostat for the furnace in. If you're just adding an A/C its not a problem.
Don Niemeyer
2006 Gulf Stream Tour Master T40A
2011 Chevy Equinox LT1 Toad

willgrab
Explorer
Explorer
OR, how about a mini split ac, very low wattage requirements and sooo quiet you wont know when it is on

Mile_High
Explorer
Explorer
If you are prewired - go for a 2nd AC. Your 5500 is more than adequate. We ran two 1500 btu ACs off of an Onan 5500 on the last three fifth wheels.
2013 Winnebago Itasca Meridian 42E
2013 Jeep Wrangler Unlimited Sahara Towed

mike_brez
Explorer
Explorer
TNGW1500SE wrote:
First I'd figure out if the old A/C is running 100 percent like it should be. If not, I'd get that one up to speed. If that wasn't the case, I'd look for ways to insulate and/or shade the RV. If all that fails, I'd add a second A/C unit. It would take me a few drinks to get the nerve to cut the roof. I would want to know exactly where to cut and defiantly cut from the inside first. It something went wrong, I could fix the interior. I'd make sure the wiring was there before cutting the roof! I'd probably DIY the job but that would be one I'd hate to tackle! There's a bunch of stuff that could go south on you. Like at said at the beginning, make sure the old unit just doesn't need a little TLC first! You could always just drive north!


No need to cut a hole in the roof the roof vent is allready there that's were the a/c goes and he said the wiring is there also along with duct work.
1998 36 foot Country Coach Magna #5499 Single slide
Gillig chassis with a series 40
02 Ford F250 7.3 with a few mods
2015 Wrangler JKU

mpierce
Explorer
Explorer
I have a 90 Bluebird. The rear bedroom AC quit. The AC guy said the wiring and thermostat would need replacing too, as they are too obsolete for the newer ACs.
So, I put an Atwood AC in. It has a panel on it to control it, and it uses a remote. NO wiring, NO thermostat, just need the power feed.

Works great. More efficient that the oem too. That is what I would do. Nice to be able to lie in bed, and adjust the temp, turn off, etc. without getting up at 2AM!

nemo45
Explorer
Explorer
Vt Rv wrote:
I have a Kabota with a front the loader. Getting it up is the easy part, no pun intended!


We used a John Deere 25 hp diesel with a bucket up front but it was still about 3 ft. short so had to pull it up 2 X 6's with a rope.
Don Niemeyer
2006 Gulf Stream Tour Master T40A
2011 Chevy Equinox LT1 Toad

Vt_Rv
Explorer
Explorer
I have a Kabota with a front the loader. Getting it up is the easy part, no pun intended!
2003 Damon Challenger 348
2011 Ford F350 Diesel
2005 Harley Davidson Electra Glide Ultra Classic
So many toys, so little time! Retirement? Tick Tock, Tick Tock

3oaks
Explorer
Explorer
TNGW1500SE wrote:
TucsonJim wrote:
it's relatively easy to install them. The big issue you might face is how to get it up on the roof. Those rascals are heavy.
Jim

Sounds like a job for some Rednecking and a tall tree!
Or a farm tractor with a front end bucket loader like I used when my wife and I changed out our AC. 😉

2oldman
Explorer II
Explorer II
Vt Rv wrote:
I have 50 amp service so will I be able to run both at the same time and run off the generator? The generator is a 5500 with 50 amp service.
Your generator may have a 50a socket on it, but it's not true 50a, which is 12,000 watts.

Your generator is (I think) 5500 watts.
"If I'm wearing long pants, I'm too far north" - 2oldman

TNGW1500SE
Explorer
Explorer
TucsonJim wrote:
it's relatively easy to install them. The big issue you might face is how to get it up on the roof. Those rascals are heavy.
Jim


Sounds like a job for some Rednecking and a tall tree!