Roof mounting questions

[RKDowner]

I'm mounting six panels to my travel trailer roof, and it's become a puzzle trying to make everything fit. One of the easy options would have the front two panels overhang the front edge a bit. Not beyond the front of the trailer, but beyond the point where the roof curves down to the sloped front. I'm concerned that this will force air up under those panels creating a strong lifting force. I'm using four Z brackets per panel, but I have some extra so I could use six or even eight on those panels. Or perhaps I could rivet sheet metal to the panel's frames to close the gap - would that work? I fear the increased drag vs. just letting the air flow under them. The alternative is one panel turned sideways back from the front edge of the trailer, and the other panel... well, it will have to be mounted at about a 30 degree angle to fit between the bathroom fan and the shower vent.

My other question is about the mounting clips. It's virtually impossible to unbolt them from the panels once they're mounted on the roof, and with the Dicor sealant they're not easily coming off the roof if I ever need to remove the panels. So I was thinking of fastening and Dicor sealing 1/2" HDPE blocks to the roof, then mounting the brackets to those. Then if I ever need to remove a panel I can unscrew the brackets and leave the HDPE blocks on the roof. What do you think? Crazy? Genius?

Any feedback is appreciated, thanks.

 

[jberger]

Here is a good thread on your question of the front airflow and aerodynamics.

Solar "Hump" for aerodynamics for Class A RV

very impressive install. pretty nice integration, I like the tent shape of the panels. You should share that somewhere in Show and Tell. you could try posting a picture directly from the side like perfectly parallel to the RV. Some of the Simulation Wizards here could create a black and gray...

diysolarforum.com

 

[HRTKD]

I used six brackets on each of my 320 watt panels. They're located at the back of the trailer.

 

[justinm001]

On the roof there isn't much airflow, everything gets directed up and above. I currently have mine angled from my girard awning top (6") to poles above my AC units (12") with huge airholes under it. To verify this I left a couple of those rods unscrewed a bit while driving through the mountains and watching to verify no movement..... and the other side are door hinges designed to lift up.

I'm willing to bet there's more wind up there when its stationary than when its moving. I plan on soon putting some wind gauge up there for weather and will know for certain

 

[RKDowner]

On the roof there isn't much airflow, everything gets directed up and above. I currently have mine angled from my girard awning top (6") to poles above my AC units (12") with huge airholes under it. To verify this I left a couple of those rods unscrewed a bit while driving through the mountains and watching to verify no movement..... and the other side are door hinges designed to lift up.

I'm willing to bet there's more wind up there when its stationary than when its moving. I plan on soon putting some wind gauge up there for weather and will know for certain

You're showing a semi with a flat front. My trailer has a sloped front that blends into the roof like this:



One of my proposed solutions would have two panels sticking out in front of the seam between the roof and the aluminum front. Not as far as the word Hideout, but definitely further than I'd like. I'm afraid air deflected up by the front of the trailer will exert too much up force on those panels. I'd rather mount them further back, but there's no room (unless I move the TV antenna, which is a whole other issue).

 

[justinm001]

I see what you mean. Most of the air should be deflected by the tow vehicle but it's still up high so there's still some air. I'd suggest putting sheet metal to cover the gap, it might create more drag but won't put much pressure on the panels. There's all kinds of risks with air flowing under the panel.

Once you put the panel down you shouldn't want to move it for any reason. I'd rather keep the dicor helping lock it down then have an additional component that's screwed up there

 

[HRTKD]

One of my proposed solutions would have two panels sticking out in front of the seam between the roof and the aluminum front.

You may find it difficult to find suitable anchor points forward of that seam. Having rebuilt the front wall of my trailer a couple years ago, there wasn't much there on the curve to screw down into.