Question about: Solar Panel install on whole roof of an RV

[pvdude]

Ours is a 2017 Winnebago 24G.
I drilled a hole in the roof to run the cables from the PV to the charge controller inside the cabin.
From inside the cabin, located where to drill by looking at where the rear antenna was installed through the roof, @ the factory.
Confirmed that I was drilling into a safe area.
The fiberglass roof is bonded to a plywood underlayment, that is bonded to 3” of foam.
(note the length of the antenna stud)

 

[MisterSandals]

Ours is a 2017 Winnebago 24G.

Ah yea, should be fairly similar to our 2008 24J.

2x 165W panels. I used to have 187W panels and you can see the permanent VHB attached brackets about 8" behind the front panel.
Attached with VHB about years. Each panel has 8 (2 each side) 2"x4"aluminum angle brackets attached to roof.

The rear panel gets a little shade from AC if i park facing south but i avoid that whenever possible.

This is a shot overlooking Anchorage at midnight, June 27, 2012.

 

[Alloy]

My Coach is built by Winnebago (Navion 24D), and only the Chassis is from MB-Sprinter ... So the roof shell is fiberglass.
I'm not sure how I could bolt down the Aluminum structures, but if that's possible I'd certainly feel more at ease.

VHB on a 1pcs fiberglass shell far better than a 1/16" fiberglass sheet glued to plywood by someone on a production line that gets a bonus for saving glue and keeps running while throwing the sheets down.

 

[HookEm]

Here's a revision that includes a "side view"... As shown, the front panel is tilted from 7" to 9", and all other panels stand at 7".
BTW, the "hump" above the front cabin on the Winnebago Navion should help minimize "lift" on the Solar panels.

 

[rcrracer]

Ummh... Sorry, but I'm not following the idea here.
(The Vent is question pushes "hot air" from the Condenser out through the top)

The idea is to distribute the hot air outward in all directions before it reaches the back of the solar panel.

 

[HookEm]

The idea is to distribute the hot air outward in all directions before it reaches the back of the solar panel.

Yes, I did get the “idea” a few pages back on this thread… but, given my space limitations, this weekend I’m going to try the design shown above, and see how it goes!

The A/C unit is now installed…The Mabru presented a few challenges, as it’s designed for the Van conversion market, and it’s not just a drop-in replacement for an RV with a standard 14x14 hole… But I found a “willing and capable“ Mobile repair outfit that got it done! (As a result, they may become an official Mabru installer for RVs)…. Anyway, my next step is to get the panels up on the roof (I’m renting a 19-Ft Scissors Lift from Home Depot).

BTW, I think the hot air from the Condenser will probably be cooler than the back of the panel above it… those panels will get pretty toasty when the Sun is hitting them… Anyway, I’m prepared to make adjustments, if that’s needed.

 

[HookEm]

OK, here are a couple of pictures of the Mabru installation... To say that I'm pleased with the way it turned out would be an understatement!
As advertised, it's quiet, efficient, and pushes out a lot of cool air! (preliminary testing showed a 42A draw on Medium settings)., Plus we were able to connect it to the existing ducting!

Of course, I'll have to wait & see how it will perform in the Florida heat & humidity... but I'm optimistic (from a Cooling perspective, I don't expect it will do any worse than a standard RV rooftop A/C... Just quieter and more energy efficient!)

BTW, I'm also showing the Scooter Carrie with a "Lift/Jack" system, which is the reason why I opted out of the Mini-Split idea... Just could not have both at the rear of the Coach,

 

[MisterSandals]

OK, here are a couple of pictures of the Mabru installation

Happen to have any picks of the install process?
Did you completely remove the acrylic hatch/skylight frame?

 

[HookEm]

Happen to have any picks of the install process?
Did you completely remove the acrylic hatch/skylight frame?

Sorry... I did not install the A/C, so I don't have pictures or details of the process.
BTW, I honestly don; 't know what you mean by the " acrylic hatch/skylight frame"... I just replaced the factory-installed GE unit and used most everything that the Mabru came with (except for their 4AWG DC wire,... I used 2AWG).

I was lucky enough to find someone with some reasonable level of experience that was actually willing to take this on!
I was turned down by at least 3 other RV repair/install outfits... They did not want to venture into the 'unknown', since this unit is really designed for Van conversions.

But perhaps they would be willing to answer some of your questions, so here is their contact info:
Julia Coheley
Master Certified RV Technician
Mobile RV Repair and Services
Mobilervrepairandservices.com
813-753-9303

 

[HookEm]

Full-Disclosure:
Although the Mabru installation does leverage the standard/existing 14"x14" opening from the rooftop A/C, these additional changes were required:
1) Mounting Bolts: Drill 4 holes from the roof-top all the way down through the Ceiling, one bolt per corner.
NOITE: Care was taken so that the holes could be capped inside of the RV without becoming an eyesore if/when replacing the Mabru with a standard roof-top A/C.
2) 12 VDC wires: Drill 1 hole from the roof-top but not all the way down through the Ceiling,... The DC wires are routed within the Ceiling structure, which is about 4" thick in the Winnebago View/Navion.
3) A/C Intake (to collect hot air from the Coach): As shown I opted to use just the Front Vent. making an extra opening in the Ceiling (inside the RV) but without going all the way up to the roof-top, so the roof-top opening remained at 14"x14". But the Front Intake opening was made as large (or just a bit larger) than the Intake on a standard 15,000 BTU RV unit, to ensure the Mabru is not compromised.
NOTE: Care was taken so that the liner *leather-like" material is rolled back to allow the ceiling opening to be refilled as it was originally, if/when replacing the Mabru with a standard roof-top A/C.
4) Connection to the existing Coach's ducting required some minor modifications to the "Airflow Director" on the Mabru.
5) To control the LP Furnace we had to replace the GE Thermostat ... Apparently the GE Thermostat requires a link to the control board on the GE root-top A/C.

NOTE: All existing (unused) roo-top connections were capped in place to allow for a seamless roll-back to a standard roof-top A/C.
Also, all modifications were consulted with and approved by Mabru, to avoid any Warranty issues.

 

[acdoctor]

Covering the a/c unit will cause condenser to recirculate causing pour performance inefficiency and shorter life.

 

[HookEm]

Covering the a/c unit will cause condenser to recirculate causing pour performance inefficiency and shorter life.

What "covering" are you referring to (on the outside or the inside)?
If you're referring to the hot-air collection inside of the Coach, then that was addressed via the Front vent (as mentioned above)

 

[acdoctor]

Referring to the solar panels covering the A/c on the roof. If the unit is designed to have obstruction near it. The exact limitations will be in the manual.

 

[HookEm]

Referring to the solar panels covering the A/c on the roof. If the unit is designed to have obstruction near it. The exact limitations will be in the manual.

OK, got it... I may have to raise the front panel a bit more to allow for enough airflow to the fan.
Thanks... I'll consider the situation and will adjust accordingly! (I have not yet installed the Solar panels)

 

[kjswiley]

I actually don't think this will help you much since the AC units are so tall, but maybe it can help give you additional ideas, or help someone else.
You wont ever be running the AC while driving right? Here is an example of what I did to clear my maxxair fans, when parked you could just go into tilt mode giving you plenty of space when the AC is on, but leaving it attached low for travel mode. I dropped the 1 in the rear to show as an example of them in travel mode. I believe you are talking about a permenan tilt, but perhaps you could do something like this instead.

This is obviously not a solution if you are on the move every few days, but as a 42 year old it is not too difficult to get them up and down, the ladder is the biggest hassle. I have not used them on the road yet, so we will see how the updraft affects things, but it is quite sturdy so I am not concerned. The nice thing with this as you can see is I was able to work around the skylight and fan by bringing the legs in a foot or so, as the frame for 2 panels went right over them.

 

[Browneye]

We frequently run the roof air driving down the hiway. [shrug]
32' class-A, if it's over 90* there's no way the dash air can keep up. Onan runs with roof air on and keeps it comfy.

 

[kjswiley]

Good point I was thinking travel trailer, and even then people could be back there.

 

[HookEm]

FYI... My Solar panel installation is described here: 1700W Solar Panel Installation on Class C Motorhome

 

[byteharmony]

I actually don't think this will help you much since the AC units are so tall, but maybe it can help give you additional ideas, or help someone else.
You wont ever be running the AC while driving right? Here is an example of what I did to clear my maxxair fans, when parked you could just go into tilt mode giving you plenty of space when the AC is on, but leaving it attached low for travel mode. I dropped the 1 in the rear to show as an example of them in travel mode. I believe you are talking about a permenan tilt, but perhaps you could do something like this instead.

This is obviously not a solution if you are on the move every few days, but as a 42 year old it is not too difficult to get them up and down, the ladder is the biggest hassle. I have not used them on the road yet, so we will see how the updraft affects things, but it is quite sturdy so I am not concerned. The nice thing with this as you can see is I was able to work around the skylight and fan by bringing the legs in a foot or so, as the frame for 2 panels went right over them.

This approach gives you lots of benefits:
self cleaning aspect
Park with an ability to raise south and angle them to the ideal angle for your present zip code / time of year (google it) for increased power
Increased power while stored --- could even have a separate set of wires for grid tie??


Another completely different idea I didn't see here was skip the panels over the AC and have a set of panels that are on the side of the RV that could angle up while parked to create a shade / angled power source.

RE the temperature dialog going on here. My experience is in direct sun light my Milwaukee panels get over 120 degrees. So if 120 degree air is blowing on a panel that is hotter than 120, it should cool it, not heat it.

Please keep posting pics, enjoying this thread.