Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-02-2015, 08:35 PM   #1
Rivet Master
 
InterBlog's Avatar

 
2006 22' Interstate
League City , Texas
Join Date: Oct 2014
Posts: 2,423
Retrofitting solar in a T1N Interstate

I'm psyched - our three panels arrived from AM Solar today, and now the DIY fun begins, because we have to design and install a mounting system.

With that in mind, if anyone out there has a T1N that came with solar from Airstream, could you please post a pic here, or PM me with it if you would prefer to remain incognito? Or if you had an upfitter install it, I would also like to see that. Neither my husband nor I have ever seen a T1N Interstate with the solar option - not in real life and not in the resale market. For reference, I'd like to see how others have accomplished it.

Our idea is to design a mounting system that vaults the panels above the A/C. I got this idea from having seen one T1N seller successfully vault his two kayaks over his A/C. The T1N Interstates came with an odd "roof rack" that is fabricated out of what appears to be some kind of ADA or hospital-grade stainless steel (it has surprisingly precise tolerances - we jokingly refer to it as the nuclear reactor piping). The rack in its present form is extremely good quality, but functionally useless for almost all purposes. I can't see us ever using it for anything truly roof-rack-able in the conventional sense, given that the A/C cover juts above the level of it. I've identified no reason why it shouldn't receive the solar panels, especially given that they are coincidentally the same width as the rack. Having them up that high would guard against the possibility of shadowing by roof appurtenances, which hasn't really been talked about much on this forum, but see Handy Bob for dire warnings on that issue.

Anyway, I'm looking forward to seeing what others have done, and/or what they have to say about these ideas. Thanks.
Attached Thumbnails
Click image for larger version

Name:	20151102_SOLAR_LOCATION_CARDBOARD.JPG
Views:	112
Size:	83.2 KB
ID:	251576  
__________________

__________________
InterBlog is offline   Reply With Quote
Old 11-02-2015, 09:19 PM   #2
Rivet Master
 
73shark's Avatar
 
2011 Interstate Coach
Overland Park , Kansas
Join Date: Aug 2011
Posts: 2,748
You might also check on the Sprinter Forum as there is a lot of discussion re: DIY everything.
__________________

__________________
Glass half full or half empty to an engineer is the glass is twice as big as it needs to be.

PM me for sale info on my 2011. SOLD!
Upfitted Transit 350 sitting in driveway.
73shark is offline   Reply With Quote
Old 11-02-2015, 09:29 PM   #3
Figment of My Imagination
 
Protagonist's Avatar
 
2012 Interstate Coach
From All Over , More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,297
One thing to watch out for, by "vaulting" the panel over the roof appurtenances, you will have a problem of uplift due to your slipstream. Whatever brackets you use need to be sturdy enough to resist that uplift force.

An angled "dam" in front of the panel, angling down and forward toward the roof, should help with that by deflecting air over the panel that otherwise would go under it. But leave a small gap between the dam and the roof to allow for vibration.
__________________
WBCCI #1105
TAC LA-4

My Google-Fu is strong today.
Protagonist is offline   Reply With Quote
Old 11-02-2015, 10:30 PM   #4
Rivet Master
 
2006 22' Interstate
League City , Texas
Join Date: Jan 2015
Posts: 503
I'm looking at about 4 different styles of tube clamps to attack to the roof rack. This is one of them:


I like this clamp because I'm thinking it might mate up easily to some 80/20 extruded aluminum brackets.
__________________
LB_3 is offline   Reply With Quote
Old 11-03-2015, 08:34 AM   #5
2 Rivet Member
 
2006 22' Interstate
San Diego , California
Join Date: Oct 2015
Posts: 37
Could you provide a source for these brackets? Thanks!
__________________
Jbray333 is offline   Reply With Quote
Old 11-03-2015, 09:06 AM   #6
Rivet Master
 
Boxster1971's Avatar

 
2013 Interstate Coach
Fulton , Maryland
Join Date: May 2010
Posts: 2,258
Quote:
Originally Posted by LB_3 View Post
I'm looking at about 4 different styles of tube clamps to attack to the roof rack. This is one of them:

.... I like this clamp because I'm thinking it might mate up easily to some 80/20 extruded aluminum brackets.

That is an awesome clamp. Looks like you could easily mount your panels above the A/C unit with that roof rack. Then add an air dam on the front of those rack bars to push the air flow over your panels as suggested by Protag.

Which solar controller did you buy? If you follow HandyBob you probably discovered he doesn't like the Blue Sky units sold by AM Solar.


- - Mike
2013 Lounge EXT on 2012 Sprinter
__________________
- - Mike
--------------------------
2013 Airstream Interstate Lounge EXT
Boxster1971 is online now   Reply With Quote
Old 11-03-2015, 03:04 PM   #7
4 Rivet Member
 
2006 22' Interstate
Mont Vernon , New Hampshire
Join Date: Nov 2003
Posts: 392
What size panels did you get?
__________________
bugsbunny is offline   Reply With Quote
Old 11-03-2015, 06:31 PM   #8
Rivet Master
 
InterBlog's Avatar

 
2006 22' Interstate
League City , Texas
Join Date: Oct 2014
Posts: 2,423
BUGS, my hubster did the sourcing, but I believe they are the same panels Lewster talked about on another thread - the ones that are no longer being manufactured. And I just noticed that they went on sale immediately after ours were delivered... hmmm...

GS100 Solar Panel | Solar Panels

BOXSTER, the packing list says "Bogart SC-2030 30A solar controller", plus a temperature sensor called "TS-2 for SC-2030".

PROTAG, you are correct about lift. Fortunately, LB_3's senior engineering project in university was a wind tunnel model which hangs in our garage to this day (behemoth that it is). So we've got some process knowledge on that issue.
__________________
InterBlog is offline   Reply With Quote
Old 11-03-2015, 08:54 PM   #9
Rivet Master
 
2006 22' Interstate
League City , Texas
Join Date: Jan 2015
Posts: 503
Quote:
Originally Posted by Jbray333 View Post
Could you provide a source for these brackets? Thanks!
4 Wheel Parts has the clamp I showed above. I'm not certain that the mounting flanges come with them however. Here is the pic again with a link below:

Trail Gear - Tube Clamps | 4WheelParts.com


Here is one sold to mount lights and speakers on Wake Board cages:

Krypt Wakeboard Tower Clamps - 1 1/4", 1 1/2", 1 5/8", 1 3/4", 1 7/8", or 2".


These are pretty clever and expensive:

Amazon.com: Rugged Ridge 11031.02 Black X-Clamp for 1.25-2" Tube Bumper Roll Bar and Cage Accessory Mount 2-Piece Kit: Automotive
__________________
LB_3 is offline   Reply With Quote
Old 11-03-2015, 09:01 PM   #10
Rivet Master
 
2014 Interstate Coach
Arroyo Grande & Central Point , California & Oregon
Join Date: Sep 2011
Posts: 529
Quote:
Originally Posted by Protagonist View Post
One thing to watch out for, by "vaulting" the panel over the roof appurtenances, you will have a problem of uplift due to your slipstream. Whatever brackets you use need to be sturdy enough to resist that uplift force.

An angled "dam" in front of the panel, angling down and forward toward the roof, should help with that by deflecting air over the panel that otherwise would go under it. But leave a small gap between the dam and the roof to allow for vibration.
I just installed two of the GS-100 panels on my AI, one of which is at the front of the roof. Although mine only has an inch or so of clearance to the roof I was concerned about the air flow under the panel so I ordered an Auto Ventshade Model 77005 (sunroof air deflector) which is about an inch longer than the panel and around 3" high. Should solve the problem in my case although it's not what the poster needs. I do agree with Protag's recommendation for some sort of air dam or deflector.
__________________
c21bill is online now   Reply With Quote
Old 11-04-2015, 12:08 AM   #11
Rivet Master
 
2006 22' Interstate
League City , Texas
Join Date: Jan 2015
Posts: 503
Quote:
Originally Posted by Boxster1971 View Post
Which solar controller did you buy? If you follow HandyBob you probably discovered he doesn't like the Blue Sky units sold by AM Solar.
As Interblog notes, I chose the charge controller designed by the guy that makes the trimetric meter. It's not the most sophisticated model (no MPPT) but if I learned anything from buying Apple products,it is that if you just want something that works, getting devices designed by a single shop is a great place to start.

Expectation management is critical to the success of any project and this is where my first failure lies. I never should have let Interblog see the panels because she is starting to get excited about being able to recharge our battery without driving or starting the generator. But that isn't what this project is about.

We're replacing our refrigerator this weekend since it doesn't operate on shore power and I've finally given up on it after replacing both circuit boards with no results. When I take the old fridge out, I intend to pre-wire a combined box on the refrigerator vent in order to route the solar power cables down into the coach.

I purchased the combiner box and charge controller with that scope in mind. But since Lew mentioned the smaller panels from AM Solar being perfect for our smaller vehicles, I figured I should pick those up as well before they are sold out.

Now I have to hurry up and figure out how to loft these things up above the AC before Interblog loses her patience with this project. :-)
__________________
LB_3 is offline   Reply With Quote
Old 11-04-2015, 12:36 AM   #12
Rivet Master
 
2006 22' Interstate
League City , Texas
Join Date: Jan 2015
Posts: 503
Quote:
Originally Posted by c21bill View Post
I just installed two of the GS-100 panels on my AI, one of which is at the front of the roof. Although mine only has an inch or so of clearance to the roof I was concerned about the air flow under the panel so I ordered an Auto Ventshade Model 77005 (sunroof air deflector) which is about an inch longer than the panel and around 3" high. Should solve the problem in my case although it's not what the poster needs. I do agree with Protag's recommendation for some sort of air dam or deflector.
Lift from your front, nearly surface mounted, panel is probably not a concern. AM solar has installed hundreds and maybe even thousands of panels using only double sided tape and their customers have never reported a failure if their website is to be believed.

There are several ways to calculate lift on an object. The first and most obvious it to calculate the pressures over the top and bottom of a surface then multiply by the area and you get a lifting force.

Bernoulli tells us that faster moving air exerts less pressure so we can conclude that the faster air over the top of the panel from the clean slip stream will result in lower pressure on the top than the slower air under the panel. This will result in a net lifting force on the panel.

Another way to calculate lift is to look at the change in momentum of the entire flow field. Since Newton tells us to expect a lifting panel to have an equal and opposite reaction on the air flowing past it. To generate lift (upward force), the flow field has to be turned (deflected) downward. As a result, we can determine the lift by calculating the mass of the air that is being deflected by the panel as the air flows past it.

Since your panel is horizontal, there isn't going to be all that much air being deflected and the fact that the panel is low to the roof limits how far you can bend the flow field since the roof will just straighten up the flow again. This interaction of the two surfaces really limits how much lift can be generated by the horizontal panel.

Now mounting a panel 12" above the roof like ours will allows for much more air to be deflected and lift to be generated.
__________________
LB_3 is offline   Reply With Quote
Old 11-04-2015, 11:19 AM   #13
3 Rivet Member
 
dennis3751's Avatar
 
1976 29' Ambassador
Fitchburg , Wisconsin
Join Date: Oct 2007
Posts: 162
I just received an email from Costco and they have Grape Solar 100 watt panels for about $135 as an online sale. Don't know if they are the same ones from AM Solar but seem to be a good deal.

Dennis
__________________
dennis3751 is offline   Reply With Quote
Old 11-04-2015, 11:51 AM   #14
Rivet Master
 
InterBlog's Avatar

 
2006 22' Interstate
League City , Texas
Join Date: Oct 2014
Posts: 2,423
Quote:
Originally Posted by dennis3751 View Post
I just received an email from Costco and they have Grape Solar 100 watt panels for about $135 as an online sale. Don't know if they are the same ones from AM Solar but seem to be a good deal.

Dennis
I'm having LB_3 check this out (he's at work this morning but I am not). Description seems like it, but pic is not the same item.
__________________

__________________
InterBlog is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Retrofitting a used ZipDee awning rcscanada Awnings 8 04-23-2012 10:33 PM
Retrofitting shocks on a '58 mello mike Shocks 2 08-18-2010 08:45 PM
Retrofitting Bunks/ Hammocks Lumatic General Interior Topics 3 06-05-2007 01:37 PM
Retrofitting Roof A/C 59toaster Furnaces, Heaters, Fireplaces & Air Conditioning 4 03-14-2003 05:54 PM
Retrofitting Old Propane Tanks (non-opd) leslie LP Gas, Piping, Tanks & Regulators 18 09-20-2002 11:24 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 10:57 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.