Ford Transit USA Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
61 Posts
Discussion Starter #1
I still do not want to fully convert my 2015 XLT wagon. We have used it for a lot of different trips now and I know a lot more about what my portable AC/heat will do and how the van reacts to weather and stuff.

By far the hardest thing to overcome is high temps with the van sitting in direct sun. My 14k btu unit will cool the van down nicely up to 95 degrees if I can park in the shade. If in the direct sun I can only get about a 6 degree drop.

I still do not want to add real insulation. My question, has anyone tried covering the van in a mesh tarp to simulate shade? The tarps claim 70% reduction in light. If that transfers to heat being transferred into the van I think it would work. I am thinking the mesh would absorb the heat and also release it into the air with any breeze. I am thinking of trying one that would cover from the windshield to the back door and down the sides to the base of the windows. We go in and out the back mostly.
https://www.tarpsnow.com/polypro-mesh-shade-tarps-70.html

Anyone tried this?
 

·
Registered
Joined
·
2,217 Posts
You'd have to support the tarp. Even draped over roof rack bars might work. But, sitting directly on the van, you would loose most of the the "shade" effect.


But, if you have a rack, it would likely be most effective to devise a permanent surface on the rack, so you would always carry shade with you.
 

·
Registered
Joined
·
61 Posts
Discussion Starter #3
Thanks Eddie,
Does your response come from experience or testing? I hope to get some real testing in this weekend. My hope is you are wrong and there will be a fair drop in the heat being developed on the medal parts and a reduction of energy coming through all my windows on the wagon.

If it does work it is a lot cheaper to put a $100 tarp on in the summer than to put good insulation in the van.

I am not worried about cold in winter. I do not plan on being out in temps below freezing and when it is close we use a heated bed pad that the 100ah battery can power all night.
 

·
Registered
Joined
·
2,217 Posts
Not experience or testing; just what I think I know.

Laying against the glass, I think you would see appreciable effect.

Will be interested in your results.
 

·
Registered
Joined
·
105 Posts
From experience, 90% shade is meaningfully more effective than 70% in desert hot condition

Shade cloth without air gap to vehicle is not going to do anything appreciable, except perhaps over windows


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
100 Posts
Take a look at the Kelty Noah 20 tarp. Good quality and not too expensive.
 

·
Registered
Joined
·
4,673 Posts
On the radio today I heard about a study comparing different types of shade. One thing they said was that shade created further away from you made for cooler temperatures. It was a story about a "human perception" temperature sensing robot named Marty, I think. My layman's concept is that you need to have some air moving between your shade source and a surface, otherwise you get conduction. Convection moves the hot air from the material away; the material gets hot because of radiation (sun). Whatever it's blocking it is either absorbing or reflecting.

Yeah, an opaque tarp, probably a lighter color reflective one like silver, suspended at least 4" above the van would keep it cooler than in the sun.
 

·
Registered
Joined
·
159 Posts
How much insulation do you have? Are you trying to avoid insulating the windows?

Sent from my SM-N975U using Tapatalk
 

·
Registered
Joined
·
2,539 Posts
Sounds like you've been listening to some pretty shady characters. ;)

On the radio today I heard about a study comparing different types of shade. One thing they said was that shade created further away from you made for cooler temperatures. It was a story about a "human perception" temperature sensing robot named Marty, I think. My layman's concept is that you need to have some air moving between your shade source and a surface, otherwise you get conduction. Convection moves the hot air from the material away; the material gets hot because of radiation (sun). Whatever it's blocking it is either absorbing or reflecting.

Yeah, an opaque tarp, probably a lighter color reflective one like silver, suspended at least 4" above the van would keep it cooler than in the sun.
 

·
Registered
Joined
·
25 Posts
An opaque tarp blocks sunlight by absorption but gets hot in the process and re-radiates infrared into the shaded area. If you don't have to worry about rain, 90% shadecloth is much more effective. It passes a bit more light but stays much closer to air temperature. Less wind load too.

I only recently learned that the traditional striped awning pattern is functional. The light and dark stripes reach different temperatures and create convective airflow around the surface even in the absence of wind.
 

·
Registered
Joined
·
258 Posts
This thing...
https://www.amazon.com/LANMODO-Portable-Automatic-Water-Resistant-137-8X82-7/dp/B07DYQKQ3T
...is too cheesy to even consider, but the idea has merit, maybe.

A more robust homemade version of garden shade cloth might be doable if you're handy with a heavy duty sewing machine.

Or maybe a Rhino Batwing awning.
https://www.amazon.com/dp/B07Q2ZL37J/ref=twister_B07S6M1K47?_encoding=UTF8&psc=1

A roof rack is the best place to start, but all awnings are vulnerable to wind damage.

My van is K.I.S.S.

(Oops, I messed up the photos, but you get the idea)
 

Attachments

·
Registered
Joined
·
84 Posts
Radiant Barrier Fabric

I purchased 10 cards of silver radiant heat barrier fabric from Energy Efficient Solutions. I cut the 10 yards (which is 59” wide) into 3 equal lengths and had a tent company sew them together side-by side to give me an approximately 14 ft x 10 ft tarp. I velcro lengths of wood outside corner moulding to my roof rack to extend over the windshield. Same for the rear window. I then drape the fabric over this. I spring clamp the fabric to the wood moulding to hold it in place. I installed grommets along the edge in case I want to tie it off or use tent poles to raise it. Seems to work. The real test will be in Florida this winter.

https://www.energyefficientsolutions.com/Radiant-Barrier-Fabric.asp
 

·
Registered
Joined
·
61 Posts
Discussion Starter #13
So, I did some testing on the material I got. The results are interesting. The data is at home but I will try to recall the basic results below. The material is black plastic. I found the same mesh tarp in an aluminized coating that may very well work much better. The cost is 1/3 higher too.

I did two tests. One was controlled indoor test with a fixed heat source and controlled breeze and two temperature probes. The second test was real world on the van.

In the controlled test I used a heat/light source with different layers. I wanted to test it with a medal sheet as close to the van skin as possible and a glass test but had to use clear glass. It was layered like this... Light/heat, mesh or no mesh, probe, glass or medal, second probe. In the testing I tried to get baselines and be sure things had settled before taking readings.

No mesh over medal: This was sort of baseline. The probe above reached 120 degrees Below the medal the probe was about 5 degrees cooler.

Mesh over medal close(<1/4"): Sort of a shock to see a 6 degree RISE in the temp between the mesh and sheet. The probe below did not rise that much though.

Mesh over Medal with Breeze: I could not measure the speed but I am guessing about 10 mph. I was expecting a drop in temps of the entire setup and I got that. But there was still a 5 degree rise between the mesh and medal.

Mesh over Medal further (about 4 inches): Shocked to NOT see that this helped. The breeze and no breeze was about the same results as above.

No Mesh over Glass: The big note from this was that the probe below the glass now reached the same temperatures as above the glass quite fast. With no breeze it may have been a bit higher.

Mesh over Glass: It was interesting to find that there was not the rise in temp between the mesh and glass. The good news is it made the below the glass probe more than 10 degrees cooler. The addition of breeze did not effect these results. Increasing the gap also did not seem to have any effect.

Real World Test...

I put a probe on the vans hood and tried to do the testing in stable full sun when the temps outside were not changing much. Same result. Higher temps between the mesh and hood by ~ 6 degrees. A stronger breeze ~15 mph and bigger gap seemed to help and drop that to about 4 degrees.

I moved the probe to the dash and put the mesh over the windshield. There was a clear 15 degree drop in the temperature above the dash.

I ran my AC and in the past could drop the van only about 6 degrees when in full sun. With the tarp I THINK I was able to drop it close to 11 degrees. The main thing that screwed that test up was some clouds that showed up.
____
In Conclusion: The mesh seemed to help a lot over the windows and more if at an angle to the sun. The gains from over glass seem to make up for the losses over medal. It did not seem to get better if the mesh was held off of the medal unless there was a strong breeze. Light breeze was not enough. If it is 95 outside the van inside with 14k btu unit would only get the van down to 90. With this tarp over the roof and all windows I could get down to 85. That is almost tolerable. With no AC the inside gets to about 115 in the direct sun at 95 outside.
 

·
Registered
Joined
·
37 Posts
i've had an idea in the back of my head for awhile on this very subject as a lot of our planned traveling will be in the SW. I've worked with fiberglass & carbon fiber quite a bit, and one interesting aspect of CF is it draws heat out of whatever surface it's in contact with and transfers it to the ambient air almost as fast as copper conducts electricity. So even just draped over the roof it would offer blocking light from hitting the roof, and reducing the heat the roof might have acquired by convection back out to the atmosphere.

But the idea i've had is, after covering the roof in mold release agent, laying down 6 oz carbon fiber cloth wetted with epoxy resin allow to cure, basically using the roof as a male mold to create an exact image of the roof. Once cured, construct blocks to position 1" above the roof, leaving the edges open to allow air movement. If there's a roof rack on the van, obviously cutouts wherever the rack mounts go, same with the roof vent, but the rack mounts could serve as attachent points - would still need to create attachment points at both the front and rear and probably need something of an abbreviated wind deflector at the front (like the front of the Thule basket roof racks) to keep the wind at speed from trying to lift it.

If you wanted to get fancy, a wet coat of epoxy with aluminum flakes mixed in could be rolled on the top to reflect sun light but i doubt that would give more than 2 degrees F additionally cooler temp under the roof shade.

CF cloth, last time i bought was $55 / yd for 60" wide cloth, Epoxy resin was almost $300 gallon and it would take about 3/4s of a gallon, but then you'd have a permanent roof shade that whether you went desert camping or to walmart, heat build up in the van would be minimized.

Total weight wouldn't be much more than a plate of cooked sphagetti

If user has solar panels on top, it'd simply be a matter of cutouts for the panels and then positioning the CF so it rested flush with the top edge of the panels, so any drag from the edge of the solar panels in the wind would be eliminated.

fwiw
 

·
Registered
Joined
·
1,131 Posts
larryccf
"Total weight wouldn't be much more than a plate of cooked sphagetti"

Lol , I like that metric , so my van weighs about 14,873 plates of cooked speggetti
 

·
Registered
Joined
·
37 Posts
LOL, okay if you want an actual "guesstimate" without working out the actual amount of cloth required, per the epoxy resin's specs for the epoxy i use, 5.8 oz of resin required for total saturation of 6 oz CF cloth and 100% of strength. Allowing 5 yards for length, + another 12" to complete the full width of the roof so let's add another 2 yards to the count and we've got 7 yards. So so far, you've got 7 yards X 12 oz (i'm rounding upward) or 5.25 lbs

Then i'd add another later of 9 oz fiberglass tooling cloth as backing to the CF, so figure another 7-8 lbs (actually less but i;m trying to be conservative). So total is somewhere near 13 lbs. My point was that it'd be light for what it is.

Another benefit, if executed like i described so it sits flush with the top surface of any solar panels, if the front edge extended down toward the front windshield some, it would eliminate wind noise from the solar panels, And it wouldn;t take much to incorporate some ribs lengthwise & cross bars so it would serve as a roof rack. so basically 13-15 lbs would replace the weight of a roof rack, eliminate all that wind noise, and give your roof some shielding from the sun. Cost for someone who knows how to work fiberglass or CF would be under $700 plus their labor, maybe 2.5 - 3 days to execute.

After i posted earlier i got to thinking about it, and it would be fairly simple to insert or incorporate a 2nd sheet underneath that one, so that once you've parked, you could simply slide out to serve as an awning. Without ribbing you would need vertical poles to support it, but i prefer that to having a 25 mph gust of wind getting underneath.

I'm toying with the idea of renting a transit while i'm waiting for mine to be delivered and fabricating that very item. At the pace i work at these days it'll take me a week+ but it'll be nice to have ready to drop onto the roof. I won't be running solar panels so that'll save me some work, but i can always cut them out later if i change my mind.
 

·
Registered
Joined
·
37 Posts
Actually not a bad setup in use, that part i like. it's the "setting up" and breaking down part plus the space the system & ladder would occupy. But he does make one point that hadn't occurred to me - rain running off the van roof just above the sliding door sill with a pull out awning.
 
1 - 20 of 21 Posts
Top