I'm planning my solar build and currently working through the arrangement of the panels on my RV. It got me thinking; using the unistrut approach the panels will sit 3-4" off the roof. Great for cooling but would imagine there will be an increase in drag. Has anyone put any thought into this or have real world experience? Not that it will change my direction but am curious if I can expect a material decrease in fuel economy.
Does roof mounted panels impact Aerodynamics?
- Thread starter Gould
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I used to have a Citroen relay van with panels on a roof rack, I noticed a slight difference. Maybe around 2mpg. More annoyingly was the whistle they caused at certain speeds, it was only noticeable with the window open. It may be worth making a wind deflector to Channel the air over them
2009Bounder2020
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roof mounting anything can affect aerodynamics... my jeep with racks and lights gets 1-2 less mph its considerably louder, but its loud with mud tires so that drowns out the sound. best move is as pyke13 said to put a wind deflector if you want to get it more aerodynamic
My RV trailer (toy hauler) has the aerodynamics of a brick, no offense intended to bricks. I'm not sure that I could make the aerodynamics much worse. The roof is inclined up from the front, towards the rear. About 5' from the rear it becomes flat/horizontal. I mounted my new panels on the flat area, trying to keep them as far back as possible without any overhang at the rear. I didn't want to leading edge of the panels to extend beyond the front of the flat section where there would (could?) be more wind due to the inclined section.
Below is a crude drawing of what I was trying to avoid. My panel sits about 6" back from where the roof angles meet.
Below is a crude drawing of what I was trying to avoid. My panel sits about 6" back from where the roof angles meet.
I feel your pain. I had a toy hauler years ago when my son was into racing. About 40ft and 18,000 lbs of barn door cruising down the highway. Worst trip was 700 km north with a serious head wind from the moment we left, averaged 3.5mpg at a time when gas was $1.50/L or $5.50 per gallon.
.I like the idea of a deflector. With the unistrut I'll be able to install them directly against each other so no real room for air to through from panel to panel. If I can find a way to gradually deflect above the first panel it should help. Trick is installing so that it doesn't become a projectile.
I feel your pain. I had a toy hauler years ago when my son was into racing. About 40ft and 18,000 lbs of barn door cruising down the highway. Worst trip was 700 km north with a serious head wind from the moment we left, averaged 3.5mpg at a time when gas was $1.50/L or $5.50 per gallon.
I like the idea of a deflector. With the unistrut I'll be able to install them directly against each other so no real room for air to dive downward between the panels. If I can find a way to gradually deflect above the first panel it should help. Trick is installing so that it doesn't become a projectile.
I feel your pain. I had a toy hauler years ago when my son was into racing. About 40ft and 18,000 lbs of barn door cruising down the highway. Worst trip was 700 km north with a serious head wind from the moment we left, averaged 3.5mpg at a time when gas was $1.50/L or $5.50 per gallon.
I like the idea of a deflector. With the unistrut I'll be able to install them directly against each other so no real room for air to through from panel to panel. If I can find a way to gradually deflect above the first panel it should help. Trick is installing so that it doesn't become a projectile.
Mine is a smaller toy hauler. Bumper pull, 25' total length. It's still like pulling a parachute behind the truck. Fortunately, the diesel engine really doesn't care.
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