2nd Air conditioner install... With pics!

[EMD_Driver]

While we were in Sevierville, TN, we stopped by Adventure RV and picked up a Coleman Polar Cub, low profile air conditioner. Their place was 12 miles from the CG we stayed in and I really didn't feel like paying the $127 for shipping the unit!

Philip and I started by removing the MaxxAir vent cover and factory vent.. Here's a picture of the hole, with the vent removed:



Here's the sealant left on the vent frame... I would almost swear that the factory used at least a whole tube of Dicor, to seal that sucker!



The original vent lid was pretty brittle and already cracked. It is a good thing a vent cover was put over it!



I spent two hours, cleaning all the old sealant from the rubber roof. I am eternally grateful to the person, that invented the hair dryer! Warming up the vent lid frame, allowed it to be removed very quickly and almost effortlessly! Getting the remaining sealant was a bit more tedious! It was a very slow process, but I was pleased with the results.





The vent had 28 screws holding it in place, as well as the Dicor. I could have used fresh Dicor to seal all the holes, but probably would not have trusted it very much. Instead, I decided to put Eternabond around the perimeter of the hole. I ran two pieces along the sides of the hole, then overlapped the front and rear pieces.

When I put the front and rear pieces on, I covered about an inch of the opening...



I cut the Eternabond on a 45 degree angle at the corners and folded it down and into the hole, just like when they installed the rubber roof.





When we hoisted the A/C up to the roof, I made sure to tell Philip not to slide it across the roof. As I went to get it fully on the roof, it decided to shift on me... I accidentally put a few un-needed holes in the EPDM! It's a good thing I already had the Eternabond up there!



We got the A/C in place, as best we could from up top and I went down to fine tune it. Here is our initial fit:



Here's what the bed looked like, before we really made a mess! You can even see the masculine pink hair dryer I used on the roof..



After we got the unit centered on the hole, I put the interior frame in and also put the four hold-down bolts in place.



Coleman installed four yellow tags on the unit. They were there, to show when the hold-down bolts were properly torqued. When the bottom of the tag was even with the roof, the bolts were tightened properly.



I then installed the output duct over the opening. This is totally different from a non-ducted Dometic A/C and is a much better design, in my opinion.



Next came the ceiling assembly.. The two wire pigtails are for the A/C control and the heat strip. The heat strip was necessary, to help keep Kitty from getting chilled while we are camping this winter. Gotta keep Kitty warm! You can also see the 12g wire, that powers the A/C. Sunline had this unit pre wired for a second A/C.



I ended up having to add a piece of 12g wire, to reach the junction box. I'm glad Philip was helping, since his hands were small enough to reach inside the ceiling and route the wire to where it needed to be. Had he not been helping, I would have had to drill and fish the wire a different way.

Here's where the wire ended up coming down:



In the junction box and ready for wire nuts:



Getting the ceiling assembly in place and lined up with the holes in the frame was difficult, to say the least. The ceiling assembly has a total of 8 screws, that hold it to the frame. The output duct ended up being attached to the opening in the ceiling assembly, using double-sided tape. I then trimmed the excess off and made it flush with the assembly.



Once that was done, I put the cover panel back on. There are washable filters on either side of the center.



I knew there would not be much clearance, between the top of the slide fascia and the ceiling assembly. Someone put some thought into the measurements of the slide!





I don't know if it was dumb luck, or more thought going into placement... Here's how the edge of the ceiling assembly and the edge of the pre-wire cover plate line up:



I turned the power back on and tested it out. The heat strip let off some odors at first, but worked perfectly. The A/C also blows ice cold and the unit is super quiet! It's a 9,200BTU A/C and should really help, when the outside temps get up there!

[Sunline Fan]

Yeah, it seems like fifth wheel bedrooms always stay really warm since they are higher up. Why they make it an option and not standard, I'm not sure. Well, I guess I'm not sure why I don't see more of them ordered from the factory that way.

BTW, I can't speak for Sunline exactly, but I suspect they had a pump/gun attached to a 55 gallon drum that pumped out Dicor right onto the roof. That's why it's such a wide band on most seams. It's like a 1/2" round tube that gushes the stuff out at the pull of a trigger- beats changing out multiple tubes for one trailer. I got up on the scaffolding at Jayco and watched them do this, and it sure makes quick work of it!

[Trailblazer]

Nice job and a great write up. Now I have to ask, how much height does the A/C unit add to the 5'ver?

[EMD_Driver]

Originally Posted by Trailblazer

Nice job and a great write up. Now I have to ask, how much height does the A/C unit add to the 5'ver?

The new A/C is 10.2 inches tall. I forgot to put the vent cover beside it for comparison, but I honestly don't think the A/C is any higher...

On another note... We had the rental car on the day I picked up the new A/C... We got it in the trunk, but it stuck out a bit.. I had to tie the trunk lid down..

[Jim-Bev-2363]

That sounds like a handy A/C size for smaller units or for one end of larger ones. Might even run on smaller generators? Bet that hasn't been done by many owners.

[EMD_Driver]

Originally Posted by Jim-Bev-2363

That sounds like a handy A/C size for smaller units or for one end of larger ones. Might even run on smaller generators? Bet that hasn't been done by many owners.

I don't see why it wouldn't work! Here's a snip from the documentation:

"Fits standard 14 x 14 roof opening. Low power consumption of approximately 11.1 amps or 1320 watts."

"Confirmed by testing as the best cooling capacity versus power consumption

Aerodynamically styled shroud that provides condenser coil protection

The vertically mounted motor and 17" oversized fan provides accelerated heat transfer to improve cooling performance.

High density polyethylene water collection pan to eliminate pan corrosion

A low profile that is only 10 inches high

Includes compressor starting components as standard equipment"

Specs:

• 1/3 hp compressor motor, the most powerful in the RV industry today
• Running Watts for Cooling - 1225 to 1450 Watts
• Approximate full load amps - cooling - 11.1 amps
• Evaporator Air Delivery on high speed - 200 CFM
• Dimensions: 44 2/25" L x 32" W x 10" H
• Weight: 92 lbs
• Optional 5,600 Btuh heating element to take the chill out of cool mornings.

[JohnB]

Gary,

Nice write up and great pic's!

I see they call the rear cover design a "Hail Guard Shroud". That never dawned on me until now. The older shrouds where wide open, and the newer ones are not.

On the roof, between the AC unit and the the rubber roof, is there a big foam gasket to create a seal?

Thanks for sharing

John

[EMD_Driver]

Originally Posted by JohnB

Gary,

Nice write up and great pic's!

I see they call the rear cover design a "Hail Guard Shroud". That never dawned on me until now. The older shrouds where wide open, and the newer ones are not.

On the roof, between the AC unit and the the rubber roof, is there a big foam gasket to create a seal?

Thanks for sharing

John

Until I saw that picture, it had not dawned on me either.. I guess we now know when they figured it might come in handy... Remember this??

Originally Posted by JohnB

Dometic themselves changed somewhere in 2004 time frame from that large opening to the covered back. I saw that at Kitty’s and EMD_Drivers T299. it had the new style cover the coils verses open. Must have had issues with the large open one.

John

There are actually three "Spacers" under the new A/C .. The main opening gasket and two more spacers in the front and rear of the unit. They help keep the load distributed, so the opening gasket does not have to hold it all. There is quite an overhang at the rear of the rooftop unit, without those spacers.

[Jim-Bev-2363]

I wonder if any of the fifth wheels have ductwork to move air from the upper deck or lower living area. Since air temps layer according to temps it would help to move hot air that has gone up to the penthouse or cool air that has pooled in the living area. A simple fan and ductwork would do that job, I think. Anyone do a mod of that?

[EMD_Driver]

Originally Posted by Jim-Bev-2363

Anyone do a mod of that?

I'm pretty sure the cool air will fall to the lowest area of the trailer, without any help from the ducting or a fan. In theory, running the upper air conditioner should keep the bedroom nice and cool. Any "Leftover" cool air would then flow down the steps. The warm air in the lower part of the trailer, should automatically flow up to the bedroom... A never ending cycle.. (At least as long as we have power!)

[ihsolutions]

We survived a very hot summer with one A/C, but found myself often wishing for a second unit. At 39' long with four slides and lots of windows, there is a ton of heat loss.

I may sell my current rig and replace it in the spring with a new model of the same, that has a second A/C and a couple other options I should have gotten the first time around, namely dual pane windows.

When I ordered this unit, I was extra cautious about pin weight, which was why I omitted the second A/C. The dual pane windows I omitted for cost.

[Jim-Bev-2363]

Gary, My intention was to attempt to force the natural flow of air, with a fan, in the opposite direction to recycle treated air, not rely on natural convection. If in the Summer it stays cooler on the main floor, then move that cooler air upstairs. The opposite in the Winter when heated air rises to the highest points. A reversible fan in duct work could move that air.

It is like in our house, a single story cinder block structure, we use ceiling fans to stir the air. When we lived in a two story home we used the duct work and fan to redistribute the air throughout the house to maintain a more constant temperature.

[EMD_Driver]

Originally Posted by Jim-Bev-2363

Gary, My intention was to attempt to force the natural flow of air, with a fan, in the opposite direction to recycle treated air, not rely on natural convection. If in the Summer it stays cooler on the main floor, then move that cooler air upstairs. The opposite in the Winter when heated air rises to the highest points. A reversible fan in duct work could move that air.

It is like in our house, a single story cinder block structure, we use ceiling fans to stir the air. When we lived in a two story home we used the duct work and fan to redistribute the air throughout the house to maintain a more constant temperature.

I understand where you are going and think it would be possible... At least in our case. The main A/C duct in our Sunny does go up into the bedroom area. If I could fit a fan into the duct forward of the main A/C, I would be able to do what you are suggesting. We do have a factory installed ceiling fan also....