New Whitest Paint Ever

[martin300662]

Originally Posted by turk123

Hey! I have an idea! What reflects light more than anything? A mirror.

We could cover the entire trailer in aluminum and polish it to a highly reflective surface, and . . .

Oh! We already have that, now?

You are falling in the same trap....a mirror reflects light and not necessarily IR, ie heat.

There are better reflectors of IR than a mirror, like sintered PTFE and some granular ceramics.

Just because something reflects visible light that doesn't mean is a good reflector of IR.

[skyguyscott]

If I understand the data correctly, a bright white roof is more effective at keeping the interior cooler than even shiny, polished aluminum. I thought otherwise, but even NASA now paints it’s spacecraft and clothes it’s astronauts in white rather than in the aluminum or silver colored flight suits used early in the space program.

Even penny pinching Thor goes to the bother of painting Airstream roofs white, and I find that pretty persuasive given the nature of Thor.

By the way, Purdue university has very close ties to the aerospace industry, and I am wondering if this research wasn’t undertaken with that in mind. I hope this paint doesn’t go the way of aerogel, an extremely lightweight Substance often described as “frozen smoke” that is evidently the worlds best insulating material, but not cost-effective to make in large quantities, and is only used on exotic applications like deep space probes and so on.

[guskmg]

I used solar panels to act as shades over my roof. I have 8, but saw recently where a member said he has 10 on his roof on his 30 footer. He must not have skylights.
guskmg

[martin300662]

Originally Posted by skyguyscott

If I understand the data correctly, a bright white roof is more effective at keeping the interior cooler than even shiny, polished aluminum. I thought otherwise, but even NASA now paints it’s spacecraft and clothes it’s astronauts in white rather than in the aluminum or silver colored flight suits used early in the space program.

Even penny pinching Thor goes to the bother of painting Airstream roofs white, and I find that pretty persuasive given the nature of Thor.

By the way, Purdue university has very close ties to the aerospace industry, and I am wondering if this research wasn’t undertaken with that in mind. I hope this paint doesn’t go the way of aerogel, an extremely lightweight Substance often described as “frozen smoke” that is evidently the worlds best insulating material, but not cost-effective to make in large quantities, and is only used on exotic applications like deep space probes and so on.

The wavelengths of light you can see are not the wavelengths that cause heat. We associate visible light with heat simply because most light sources cover several regions (ie sunlight), but, by eye you can not see the wavelengths that cause heat (as the name suggestions you can only see visible light - unless you have a Geordi La Forge style visor anyway!).

How white a coating looks, or how shiny a mirror is, only relates to visible light, and is only by association even remotely relevant to absorbing/reflecting heat (because often light sources have IR wavelengths (ie heat), also have visible and UV wavelengths). Heat reflectors may reflect very little visible light (and vice versa).

[JCWDCW]

[QUOTE=skyguyscott;2484460]
But folks tend to like the bare or polished aluminum look (or at least clear coated). If Thor did put out an all-white trailer, it would likely come with those annoying swoosh vinyl graphics that cover all the SOB's. And if not, owners would see the white as a blank slate to add their own personalized graphics, all of which would negate the thermal advantages./QUOTE]


I've always wondered why the blank bare aluminum isn't treated as a blank canvas by more owners. Today's graphic systems lend well to panorama and nature scenes.



I think Airstream learned the lesson well from past experience. Graphics and stripes in the 90's ended up blistered and peeling and making an awful mess that simply can't be removed without aggressive chemicals. You don't see many graphics on the last 20 years of AS models. Our '94 Award decals and graphics all crazed in less than 5 years.
I just had my '96 stripped because the stripes were burned on from 25 years of sun.
Had planned to polish it but someone came along and offered me the price I paid for it 17 years ago so it is now his challenge.

Plan to upgrade our 16 ft Bambi for a 23Ft when one comes available.
JCW

[Wazbro]

Originally Posted by skyguyscott

Even penny pinching Thor goes to the bother of painting Airstream roofs white, and I find that pretty persuasive given the nature of Thor.

I'm fairly certain Thor does not paint the roofs. They just order them with a white coat instead of clear coat. Probably the same price or less.

[21Airstream]

Originally Posted by martin300662

Then apply Bus Kote.....

Just an example; what color is the underside of the space shuttle? Black, yes? Yet that is the part designed to dissipate heat. Reflection is just one way to dissipate heat.

This story is exactly what happens when mainstream media get a hold of a story and promote to the public because they think it is a good idea without the scientific understanding behind it.

But if you really want to use science and engineering to make an aluminium constructed trailer/motorhome more efficient, you start by looking at the materials of construction. That means not looking at coating something that is constructed from materials that are excellent at thermal conduction, but rather change the materials of construction. In those terms, applying a thermal efficient coating to an Airstream/Argosy is literally 'putting lipstick on a pig'.

I’m not an Engineer or a Scientist, I’m just a retired guy that always wanted an Airstream and finally bought one seven years ago. I’ve had a couple of SOB’s in the past and our FC 27FBQ seems to be a “less is more” kind of rig compared to them. It tows like a dream and I don’t know of any wasted space in it. (I carry most of the heavy stuff in the bed of the Ram.)

I hope in the future to have a second a/c installed (thus the interest in the “whitest” paint for the roof. (I also would like to have a lift kit installed and maybe some solar panels someday.) I’m not interested in doing anything that significantly changes its appearance though (I even went with the same style wheels when I upgraded to 16’s).

[martin300662]

Originally Posted by 21Airstream

I’m not an Engineer or a Scientist, I’m just a retired guy that always wanted an Airstream and finally bought one seven years ago. I’ve had a couple of SOB’s in the past and our FC 27FBQ seems to be a “less is more” kind of rig compared to them. It tows like a dream and I don’t know of any wasted space in it. (I carry most of the heavy stuff in the bed of the Ram.)

I hope in the future to have a second a/c installed (thus the interest in the “whitest” paint for the roof. (I also would like to have a lift kit installed and maybe some solar panels someday.) I’m not interested in doing anything that significantly changes its appearance though (I even went with the same style wheels when I upgraded to 16’s).

I would recommend Bus Kote over any simple 'paint'. If you have a existing white roof, you will not see any difference. I don't have 'before' data for our Argosy but it simply does not get hotter than ambient inside, and having two FanTastic fans (one blowing in, one sucking out) creates a cooling breeze. With a AC mounted within a nightstand between two twin beds and simply never need to turn on. It also means I only needed a small (tiny house) AC that runs on the inverter so does need shore power/generator.

[doughpat]

Originally Posted by martin300662

I would recommend Bus Kote over any simple 'paint'. If you have a existing white roof, you will not see any difference. .

Can you clarify? Are you saying Bus Kote is not going to be any better than the factory white coating ("paint") that comes on later model AS?

We do not have A/C (low bridge took that out for us), and we are certainly interested in the idea of reflecting as much IR as possible....1 degree difference would be worth it for us!

[21Airstream]

We do have the white roof and two FanTastic fans on our Airstream and they’re adequate until we visit Texas. It’s nice to have options.

[martin300662]

Originally Posted by doughpat

Can you clarify? Are you saying Bus Kote is not going to be any better than the factory white coating ("paint") that comes on later model AS?

We do not have A/C (low bridge took that out for us), and we are certainly interested in the idea of reflecting as much IR as possible....1 degree difference would be worth it for us!

Bus Kote is a significant improvement in reflecting heat, but visually looks the same - you literally will not 'see' any difference.

[sarge12212]

I just finished coating my '76 30' Excella 500 rooftop with 3 coats of Henry Trop-i-cool white silicone roof coating. It's 91° outside here in St. Augustine, FL and 73° inside the camper in full sun, as of 5 minutes ago. A/C is on low cool. It's 10-12 degrees cooler than it would normally be at that temperature. Awesome! ����