| zip dee awning [message #304033] |
Sat, 23 July 2016 12:06  |
kstockwell
Messages: 367
Registered: May 2016
Location: Putney VT
Karma: 4
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We camped in a field last weekend, it was hot, it was sunny.
My Zip Dee awning is brown and beige stripes. We had fun playing with the laser remote temp sensor, the brown stripes were a good 10 deg F higher than the beige. 125 vs 115. It felt like the awning was radiating down on us and making it hotter.
Is there anything I can do to reduce this other than getting new fabric? I noticed the 10x20 easy up we had with white tarp on it was 20 degrees cooler than the awning (but of course not as cool looking).
The awning also leaked a bit so I bought some of the Sunbrella approved weatherproofing spray (hello carpal tunnel tomorrow with the pump spray)
I'm assuming this won't have an effect.
Does anyone else have this issue? Is putting a reflective tarp over the awning a good idea?
thank you
kelly
1978 Kingsley
Putney VT
[Updated on: Sun, 24 July 2016 07:33] Report message to a moderator |
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| Re: zip dee awning [message #304126 is a reply to message #304119] |
Sun, 24 July 2016 13:02  |
kstockwell
Messages: 367
Registered: May 2016
Location: Putney VT
Karma: 4
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thanks, that is true- it's not necessarily hotter underneath because the awning is hot.
They make these dog crate mylar tarps that let air through, i'm ordering one 6x6' for the end of the awning. if it were cheaper I'd get a huge 6'x 30' roll and run it across the whole awning but that would be hundreds of dollars
I'll experiment and report back.
two containers of 303 and I soaked my awning in water repellant (especially where there are seams). I rolled out the awning 3' at a time and went across.
fingers crossed.
kelly
1978 Kingsley
Putney VT
[Updated on: Mon, 25 July 2016 07:03] Report message to a moderator |
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| Re: zip dee awning [message #304197 is a reply to message #304181] |
Mon, 25 July 2016 07:01 |
kstockwell
Messages: 367
Registered: May 2016
Location: Putney VT
Karma: 4
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It really felt like the awning was radiating heat down to us. It's not a tall awning so we're only 4' below it sitting in chairs sweating like the gin and tonics in our hands.
And yes, just because the brown stripes were hotter (via laser remote temp) doesn't mean they were emitting more heat to us. What I can also do is put something under the stripes and see if it gets hotter under the brown vs white.
I'm curious about throwing a white tarp over it to see what that does.
kelly
1978 Kingsley
Putney VT
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| Re: zip dee awning [message #304212 is a reply to message #304197] |
Mon, 25 July 2016 10:08 |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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White= presence of all colors and black=absence of all colors. As Mark said, the darker colors are absorbing more of the color wavelengths and so get warmer than light colors. And that energy has to go somewhere, otherwise the energy would break the atomic bonds of the materials and turn it to dust immediately. So it radiates in all directions, one of which is down on you. The lighter colors reflect more color wavelengths and so do not absorb and store as much energy. However, on your fabric shade, much of that light energy passes through, continuing on to intersect with everything under the awning, unless you put a non-transmissive barrier in the path of the light energy.
When Dad had to replace the convertible top on the Oldsmobile, he got a black top instead of the yellow that came with the car because it looked better on a yellow car. After that, the AC would not handle the heat load radiating inside from that black top. The fix was INSULATION on the inside of the top, as you surmised in your last post. We used a mattress pad/cover that was about 1/4 to 3/8 inch thick and were able to tuck it in between the side pads and the top bows held up the rest of the material. What a difference...the car was usable in the broiling sun again while barely moving in traffic. This solution may be difficult to implement on that awning unless there are enough bows or stitching to hold the insulation up. It also is not going to tolerate getting soaked by rain making it through the awning, as it will absorb the water and may crash it due to too much weight. If you can keep it dry or make it removable during a rain storm, it will make a big difference in the amount of heat radiated toward you and also reduce the light energy passing through the lighter colors. Make sure that whatever insulative layer you try under the awning is white, otherwise it will just amplify the energy storage capacity of the entire system.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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| Re: [GMCnet] zip dee awning [message #304215 is a reply to message #304211] |
Mon, 25 July 2016 10:50 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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G'day,
Here's some information about heat rejection vis-à-vis fabrics:
https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=space%20suit%20layers
If you click on this link you will find a myriad of fabrics that Zip Dee makes awnings from:
http://awningsbyzipdee.com/68901.html
You will notice that the fabric is Sunbrella so I called them and asked if any of their fabrics were designed to reject heat more
than others and was told no. The lady I spoke to advised what we all know, light colors reflect the heat better than dark.
Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of James Hupy
Sent: Tuesday, July 26, 2016 12:57 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] zip dee awning
Generally speaking, lighter colors reflect light and heat, while darker
colors absorb it. Not precisely exact because some colors block better than
others. Aluminum impregnated fabric precisely manufactured for awnings is
the top if the heap. Also the ugliest. Can't have everything I guess. Which
comes first, form or function? That argument will not be answered in my
lifetime, I bet. The earliest spacecraft were painted with alternating
stripes of highly reflective polished metal and flat black energy absorbing
coatings to control internal temperatures.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
On Jul 25, 2016 5:02 AM, "kelly stockwell" wrote:
> It really felt like the awning was radiating heat down to us. It's not a
> tall awning so we're only 4' below it sitting in chairs sweating like the
> gin and tonics in our hands.
> And yes, just because the brown stripes were hotter (via laser remote
> temp) doesn't mean they were emitting more heat to us. What I can also do
> is
> put something under the stripes and see if it gets hotter under the brown
> vs white.
>
> I'm curious about throwing a white tarp over it to see what that does.
>
> kelly
> --
> 1978 Kingsley
> Putney VT
>
> _______________________________________________
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: [GMCnet] zip dee awning [message #304222 is a reply to message #304215] |
Mon, 25 July 2016 11:52 |
kstockwell
Messages: 367
Registered: May 2016
Location: Putney VT
Karma: 4
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Senior Member |
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This is all good to keep in mind when getting an awning or if you want to replace your existing one.
Completely true on colors absorbing/emitting, brown is close to black and therefore I have some brown-body emission going on from the awning down to me.
The yellow and white striped awning colors at Sunbrella now look pretty appealing.
That's great you called, I'm actually surprised they don't offer fabric that has reflective properties in it maybe in the future.
What I really thought was the 10 degree temp difference between the colors was interesting, and even the beige stripes compared to the white tarp on the 10x20 next to me. Very cool tidbit about the early space ships!
I know heat reflecting roof paint exists but I'm not painting the awning.
thanks for all the chime ins!
kelly
1978 Kingsley
Putney VT
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| Re: [GMCnet] zip dee awning [message #304233 is a reply to message #304224] |
Mon, 25 July 2016 15:01 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
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Senior Member |
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I had this problem exactly. My coach came with a really pretty dark blue awning. It matched the dark blue coach perfectly.
It also adsorbed every photon within 100 mile radius and converted them to heat.
I swear It was hotter under the awning than in the sun!
I replaced it with the lightest silver/white awning I could find. It's night and day different.
The white does not transmit the light like someone said below, mine is opaque, it bounces those nasty photons back into space leaving it cool and shady under the awning.
For a cheap fix get some of that aluminumized bubblewrap and cover the awning, It will go from Zero to Hero instantly.
Depending on your level of backwoods hacking you could probably paint the awning silver and save a ton of money.
Probably would look pretty tacky tho :)
>
> kstockwell wrote on Mon, 25 July 2016 07:01
>> It really felt like the awning was radiating heat down to us. It's not a tall awning so we're only 4' below it sitting in chairs sweating like
>> the gin and tonics in our hands.
>> And yes, just because the brown stripes were hotter (via laser remote temp) doesn't mean they were emitting more heat to us. What I can also do
>> is put something under the stripes and see if it gets hotter under the brown vs white.
>>
>> I'm curious about throwing a white tarp over it to see what that does.
>>
>> kelly
> A white tarp will improve the situation, immensely. Try it.
> --
> 73 23' Sequoia 4 Sale
> 73 23' CanyonLands Parts Unit 4 Sale
> Upper Alabama
> "Highest price does not guarantee highest quality."
>
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Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
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| Re: zip dee awning [message #304235 is a reply to message #304197] |
Mon, 25 July 2016 15:33 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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When we were weighing coaches at the Branson summer rally it was 97 degrees outside. I borrowed one of those 10x10 popup awnings from Jim K. so the workers would have something to hide under away from the sun. Unfortunately it was dark blue and every time you walked under it, it was hotter than standing in the direct sun light. It was like there was a heat lamp in the awning pointing down at you.
If I ever buy one of those things, It will be white or very close to it.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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. HF should have an inexpensive tarp to make it worth the experiment, let us know if it works if you try it. 
The color math is the same though, just check with your local art teacher. Remember, there is a big difference between transmissive and reflective materials in the amount of energy that passes THROUGH them.