Replacing coleman AC with Carrier low profile

[MS325]

Here is our next edition of a how-to.

We just installed two new Carrier low profile air conditioners in the 325 and thought we would post a procedure for everyone. We did our own proofreading so let us know if we missed anything if you've already done this. Thanks,

Mike & Josh

Replacing Coleman factory Airstream Air Conditioners with

Carrier Low Profile Air V Units

By: MS325 & Fish36990

Difficulty Level: 3 of 10

Tools:
Scaffolding (Fig 1 - an absolute must – rented from Home Depot for $54.00/week)
Standard socket set
Phillips & Standard screwdrivers
Tin Snips
Utility knife
Air Compressor
Compressed air spray nozzle
Bucket of water, scrub brush, and shop towels
TremPro 635 & caulk gun TremPro purchased from (www.vintagetrailersupply.com)

Procedure:

Removing Coleman Air Conditioner Units:
1. Remove two control knobs from panel by simply sliding them off.
2. Remove four Phillips head screws holding outer housing on the panel inside the motorhome.
3. Remove six Phillips head screws (ours had white heads) holding lower galvanized panel to the AC unit and disconnect the connector to complete free panel.
4. Verify the shore motorhome is not connected to shore power and disconnect the romex cable inside the power upper galvanized panel. Also disconnect the last factory connector from the AC control area of remaining panel.
5. Using the scaffolding and a 7/16” socket to remove the rails from the top of the Coleman AC unit on the roof. ( Fig 2 - Walk on the roof as little as possible to prevent/reduce denting. When walking on the roof is necessary, stay on the ribs.)
6. Slide AC cover off of the AC unit. (Fig 3)
7. On the inside of the motorhome, remove three long bolts connecting the interior panel to the roof AC unit. (Fig 4 & 5 & 6)
8. Lift the AC unit out of the pan and remove from roof. (This is a two man job)

Prepping pan for Carrier Installation
1. Vertically clip the corners of all raised sections of the AC pan with tin snips.
2. We were able to fold the pieces back and forth until they mainly snapped and we just trimmed them with the utility knife. (Fig 7-10 - We realize this will upset some Airstreamers but we felt this was the most reliable way for long term use)
3. Use the compressor and the nozzle to spray down the drain tube in the pan to completely clear any debris from tube.
4. Use your water and brush to clean the pan and dry with shop towels.
5. Apply TremPro 635 where needed to prevent leaks between pan and motorhome shell.

Installing Carrier AC Units
1. Be sure to drill drain hole in the bottom of unit (center of white nipple on the bottom near the front)
2. Place Carrier unit on roof and roughly align unit above hole.
3. Inside of the motorhome, realign the unit so the drain hole is directly above the existing drain cup and tube in the pan.
4. Use a pencil and mark where trimming is required for the four bolts to clear all metal during assembly as well as the duct rectangle on the bottom of the unit.
5. Trim all metal marked in previous step.
6. Attach flex duct to the unit on the roof using bracket provided. (Fig 11 - fold the precut side over the four sides of the bracket and install four screws to hold in place)
7. Rout all wiring to the correct location while sliding the interior panel up the flex duct.
8. When interior panel is in the correct location, insert the shorter two bolts in the front of the AC unit and two longer ones in the back to secure the interior panel to the unit on the roof. (You will have two long bolts left over when using the shorter ones on the front)
9. Tighten them evenly and compress the main gasket to 60% (This spec is from the directions that came with our Carrier) and it should compress unit the rear pads are barely touching the roof of the motorhome.
10. Cut the corners of the flex duct up to the where they come through the interior panel. Fold the four cut pieces back and install the remaining duct bracket to secure the lower end of the flex duct. Trim extra duct material.
11. Connect the electric wiring to the motorhome romex wiring. Also, install the connector from the roof unit to the interior panel socket.
12. Reconnect to shore power and test unit. (Fig 12)
13. To attach the front control panel to the interior panel, we will have to trim the plastic on the side to accommodate the curve of the roof of an airstream.

[MS325]

Pics Fig 9 through 12

M&J

[ArtStream]

Thanks for taking the time to photo this install guide, Karma coming your way!

Question, is there a gasket between the pan and the roof?

[MS325]

There was no gasket between the pan and the roof. It looks like it is just caulked down with the trempro from the factory. Our had come loose on the rear of both units and may have been the cause of a couple of leaks we were hunting.

It looked like they just tried to make it flat and level and filled the gap between the pan and roof with TremPro.

M&J

[outofcontrol]

Awesome post...I love this kind of stuff.
I would love to upgrade my AC units, but the ones I have work so well I'd only be doing it for the looks. Mine seem to stand out so much - those low profile ones look so much better. I wonder if a sheet metal fabricator could make some shrouds out of Alum. for them - with smooth corners...

What were all the reasons you did the upgrade? - you mentioned leaks.
Do they do a better job cooling the RV? - I know Nov. is a bad time to really test them, but is there a signifigant difference?
Where did you buy them? Which model did you choose? How much?
I imagine all those lips that you cut off were originally there to prevent water from getting inside. Does the new installation inspire confidence that they will not leak? Did you test with a hose? ---I live in Oregon-9 mos. of rain.
Now that I'm looking at the pictures again I realize that the part that you trimmed is the pan from the original Coleman units. Is it possible to remove the pan entirely?

Thanks for the post. These kind of reports/How-to's are exactly what this forum is for.

-Kevin

[Boondocker]

Originally Posted by outofcontrol

Awesome post...I love this kind of stuff.
I would love to upgrade my AC units, but the ones I have work so well I'd only be doing it for the looks. Mine seem to stand out so much - those low profile ones look so much better.
-Kevin

I thought about that too, but I was also thinking less wind resistance and mpg. How much shorter are the low profile units?

[outofcontrol]

7.5 inches tall. I think my colman originals are about 12-13" tall.
http://www.pplmotorhomes.com/parts/r...file-rv-ac.htm
I doubt there would be any effect, but I guess every bit counts.
13.5 BTU unit on Ebay for $549 Item number: 140048478476

-Kevin

[Robfike]

MS325,
Great post, thanks for the info. In your picture of the finished project I noticed your center stripe. Is this just a light grey with some pin stripes? Looks great. Can I get a closer picture? I have been thinking about something different for our 345.
Thanks, Rob

[A-Merry-Can]

i've got a low profile on my trade wind, and my buddy's got one on his trotter. we love em. one note, though we did have to go back a few weeks later and retighten the bolts that squeaze the foam seal down. ours started leaking condensation through the interior control panel. i think it pools one one side of the unit, if the trailer isn't 100% level. after we tightened ours, it hasn't leaked since.

they look great, though. you can still tell there's an AC up there, but it certainly looks better than the big top hats.

jp

[hendrie42]

great post verry complete----heres a karma------

[MS325]

Kevin,
You seemed to have answered several of your own questions but I'll answer the rest. The reason we decided on an upgrade was mainly due to plans to hit the road alot in her and really didn't want to worry about them going out. The old ones still worked but not to the best of their ability. The low profile Air V's have an air shower which is supposed to be the cat's meow. We'll have to give a final approval when it gets warmer. We finished sealing them in right before the big front that was flooding everywhere came through TN and there was not a single drop inside the motorhome. I guess the coleman pans could have been removed completely...I didn't see any reason that they couldn't have. There would be a lot of time removing all the caulk and we wanted as flat of a surface as possible to compress the gasket down to so we just trimmed them. The pan on the coleman was seperate and the pan on the Carriers was built in, so we just drilled the drain hole into the Carrier pan which happened to line up the drain 'sink' in the old Coleman pan. Leaks should be no problem.

Rob,
It is a light grey strip with red pin stripping on the upper and lower areas of it. I went through a bunch of airstream 'how-to' pics and there are none that area really good shot of the strip. We'll take a good one tomorrow and post it here for you to check out.

Feel free to ask any questions and thanks for the kind words,

Mike & Josh

[outofcontrol]

Thanks. This is one of my top 5 things to do. Now I'm excited to do it.

-Kevin