Figuring out my van's roof space

[waldenbound]

I think I'm at a place where I can get the walls up on my van. Now, I have to think about how much space I have on the roof for solar panels and fans. I want to get two FantasticFans, and hopefully have enough space for two flexible solar panels.

I have a backup camera so I have to leave the driver's cockpit area alone. The cargo area is about 8 feet long. Is that enough roof space for two fans and two solar panels? I know I have to put the fans in between the ribs. I could even go fan, panel, fan, panel if need be.

Anybody got any advice? Van is 2011 Chevy Express.

 

[LeeRevell]

Depends on the size of the panels. Get up there and measure your actual roof acreage. Don't guestimate.
Maybe draw out the layout in scale, and try different layouts. One member here some time back drew the van layout, then used paper cutouts to represent items to be fit in.

 

[frater secessus]

If you wanted to get crazy with it you could mount the panels on a high rack and put a lower-rise fan (like the Maxxfan) underneath.

 

[DrJean]

I don't know about Chevy... you know I find great information for my Transit build at the Ford Transit forum... have you looked into, read, or joined a GM Chevy Van board? They have all the measurements and ideas and such pertinent to the model of the Chevy's they own.

Good wishes! Remember, for every 2 people you ask you'll receive 3 opinions

 

[highdesertranger]

it's best to make sure the vents don't shade the panels. depending on the size of the panels you should be able to get 2 panels and 2 vents. break out the tape measure and paper. highdesertranger

 

[ArtW]

Measure twice, cut, ummm, wait a minute, that's not gonna sound right

 

[Optimistic Paranoid]

You've been given some good advice so far, especially hdr's advice about not shading the panels, this can DRASTICALLY reduce their output.  People are often surprised by how much.

Consider having a ladder rack installed on your van.  Mount a second roof of plywood on it.  Mount your solar panels on IT, with your vents underneath.

This will have the following positive effects:

1.  Nothing to shade the solar panels.

2.  The shade it provides to your vehicle's roof will keep the vehicle cooler.

3.  During a rainstorm, it will prevent a "rain-on-a-tin-roof" noise which many people find annoying and which keeps them from falling asleep.

4.  Because the plywood roof protects the roof vents, you can leave them open during a heavy storm, instead of having to close them to prevent water from entering.

There are a couple of downsides:

1.  The vehicle will be a little higher, which may mean you can't go through drive-throughs.

2.  It may cost you a mile or two on your mpg due to extra wind resistance driving down the road.

Take a look at this blog post of Bob's, showing how he did this to his trailer:

http://www.cheaprvliving.com/heat-cold/dealing-heat-cold/

 

[MrNoodly]

Avoid flexible solar panels. First of all, the silicon crystals used in them aren't as efficient as the ones you can get in rigid panels. Secondly, solar panels need air circulation on the underside in order to keep from getting too hot.

As for vent placement on a standard length Express, if you put one just aft of the rib/truss that aligns with the front of the side door opening, and put another just aft of the rib/truss that holds the standard interior light, you have about 5.5 feet of roof between them.

But, of course, you could always install the vents first then see exactly how much space you have left for solar panels.

 

[TrainChaser]

Mark out the actual measurements on the roof with a dry-erase pen.

 

[MrNoodly]

Mark out the actual measurements on the roof with a dry-erase pen.

Or with tape.

 

[rvpopeye]

Typical panel width is 24-25" (you'll really have to check the ones you have/get).
Roof vents a little less than 18".
Good advice already on shading the panels and roof rack double roof.......^^

 

[Almost There]

My only advice in addition to all you've already got - don't put a roof vent over top of your bed unless it is well protected (vent cover or  solid wood)!

Many of us found out the hard way that it's a guarantee that sooner or later you will be somewhere other than at your van when it starts to rain and the vent is open.

Sleeping in the wet spot is no fun at all!...

 

[rvpopeye]

I'm gonna be good and stop right now...................

 

[waldenbound]

I think the roof rack with panels on it and the vents underneath sounds like a good idea. So, the vents under the panels won't impede the airflow? I'm adamant on being able to bring in fresh air and draw out hot air, hence the two fans.

Almost, too funny! LOLOLOL

 

[MrNoodly]

If you put the panels directly over the vents, the rack and panels need to be far enough from the roof to allow the vent lids to tilt open, and they have to open a certain amount before they'll turn on. Most racks won't let you do that unless you customize them somehow.

 

[waldenbound]

If you put the panels directly over the vents, the rack and panels need to be far enough from the roof to allow the vent lids to tilt open, and they have to open a certain amount before they'll turn on. Most racks won't let you do that unless you customize them somehow.

Ok, so I can get the fans put in, then the ladder rack, and then space my panels to allow the fan's lids to open.
I don't need a lot of solar, just enough to charge the Big Three gadgets (laptop, iPad and cell phone.) But solar is down the road and there will be plenty of questions when that time comes.

Big thing now is planning my roof space, and getting fans installed.

Thanks everyone.

 

[highdesertranger]

remember MaxxAir vents/fans are lower profile. highdesertranger

 

[MikeRuth]

Can I ask why two vents/fans? I tell ya I have one Max Air on the same size van as yours and it does the job just fine. it's at the rear, I crack open both side windows about an 1.5", I have vent visors so you really at a glance can't tell the windows are down. On medium setting it moves a lot of air! I have two solid solar panels on a roof rack. 240 Watts.
Whole system works really well.

Mike

 

[waldenbound]

Can I ask why two vents/fans? I tell ya I have one Max Air on the same size van as yours and it does the job just fine. it's at the rear, I crack open both side windows about an 1.5", I have vent visors so you really at a glance can't tell the windows are down. On medium setting it moves a lot of air! I have two solid solar panels on a roof rack. 240 Watts.
Whole system works really well.

Mike

Well, I got animals I have to worry about. I've heard rvers say that with two fans, their pets are fine. Of course a van is smaller.
So one fan really moves air and keeps the temperature reasonable?

 

[DrJean]

Okay my 2 cents on this one.

Why go with roof solar at all if that's all you want to charge? A smart phone probably takes about 5 w? Ditto the other items. You can buy a portable, foldup backpacker's solar system that charges those items, and recharges in a few hours of sunlight for under $100.

Worry about the big solar later on when big advances in the technology are in place (coming to a Country near you soon!) imo.