Solar reflective auto paint
 

The findings reported here might be of interest to some of you, especially if you are considering buying a car or repainting yours:

Cool Science: Cool Cars | Heat Island Group | heatisland.lbl.gov

Here's the core point:

The site cites this study for the above information:

Levinson R, Pan H, Ban-Weiss G, Rosado P, Paolini R, Akbari H., "Potential benefits of solar reflective car shells: Cooler cabins, fuel savings and emission reductions," Applied Energy (2011).
http://heatisland.lbl.gov/publicatio...-and-emission-

Indeed?

http://bringatrailer.com/wp-content/...J40_Rear_1.jpg

I've always been a fan of white roofs for this reason (even reducing duty cycle of factory equipped "overpowered" a/c unit, which has to be almost as good as having a smaller one...) - all our non-A/C cars received white paint jobs on the roof when I was a young'n... and I've been putting some serious thought into doing up my WJ that way.

California98Civic -

We've always had white cars in my family going back to my Dad's 1960 Chevy Impala (not ours but close enough) :

http://ecomodder.com/forum/member-cf...evy-impala.jpg

My Dad's an engineer, and I am pretty sure he told me that he picks white for cooling reasons.

This is true of homes as well. Aesthetically most people wouldn't select white roofs, but they $ave a lot of money and degrade slower than traditional roofs. I remember driving out of Las Vegas one day and seeing a *WHITE* Spanish tile roof on a home. I just wanted to clap my hands.

More studies :

FSEC-CR-1220-00

http://www.fsec.ucf.edu/en/publicati...ges/WStile.jpg
CarloSW2

Same here... have had only white cars since as far back as I can remember... (part of the reason my avatar is white too! :) )

My car is black, so i seek out the shade,desperately when parking during the summer. In the winter my car benefits from being warming do to the solar heat.
Also black is waaaaaaaaaay cooler of a color choice.
White won't cut it fer me, especially in my N Beetle..
I do like grey/silver.

That white tile house roof... damn... that looks good. Even without the thermal benefits it just looks good.

I've long admired this one, which I often pass on the way to one of my favorite hiking/biking trails: Carson Valley Nevada Real Estate - Gillmor Coons Real Estate Group | Search Properties If it weren't such an overkill - 13 garages! - I'd make an offer.

Likewise with white cars: the thing I regret most about my Insight is that it's silver instead of white.

ecomodded -

The other good thing about silver is that unpainted pizza pans are close in color.

But white can look wicked :

http://ecomodder.com/forum/member-cf...-because-i.jpg

CarloSW2

jamesqf -

That's egg-zactly the picture I was looking for, one where you could see the classic Spanish tile roof :

http://www.idxcentral.com/images/mls...005829_1_n.jpg

CarloSW2

Still waiting for this vaporware colloid. Getting a charge out of solar 'paint'

Have always had white colored cars to help keep the interior cooler (although the portion of the interior heating due to the greenhouse effect through the windows is unaffected by car color). Recently whitewashed the roof on my house, which resulted in a noticeable reduction in A/C and attic fan operation running and making it possible to work on the roof in the middle of the day without getting a hot foot or burning up from all the heat radiating up from the shingles. Another advantage of having a white surface is it reduces the surface temperature change from day to night, which should increase the life of the paint or roofing material since it is not being as thermally stressed.

i have been thinking about using this on my rear windows to cancel the greenhouse effect.

http://img.diytrade.com/cdimg/764986...ated_vinyl.jpg

this would be really cool

http://www.geekstir.com/wp-content/u...8912914782.jpg

My last truck was white,with a copper canopy, it looked pretty good really.
"White is alright" but silver looks sharp
notice the white Bugatti behind it.

ecomodded -

Yeah, my wife loves silver, so that plus the pizza pans would make silver my second choice. I've had this same conversation with my nephew. He finished his industrial design degree last year and his goal is to design supercars someday. He likes white because he can *see* the lines of the car better. However, he was mostly comparing white to black.

CarloSW2

redorchestra -

I should do the same. Here are some examples of "perforation density" :

CLEAR FOCUS Manufacturer of one way vision products, perforated vinyl, see through window graphics

Here's a monster roll for sale :

Roll of Intermediate Window Perforated Vinyl (one way vision) 6.3mil 38.5"X164'@ 00884962282878 | eBay

We should be able to buy some from a sign shop.

CarloSW2

So... for purposes of automotive roof painting, now that I've been reminded to do it and have put a bit more thought into it -

What's the thought on a bright silver flake type paint color vs. white paint? (my car's dark "graphite metallic" so silver flake would look better )

...just about everything NASA puts up into space is WHITE for a reason, unless it's gold for reflectivity!

In addition to a reduced daily thermal cycling, another advantage of white is that it is reflecting all of the (visible) wavelengths of light, thus avoiding the longevity problems seen with red and black paint, which are absorbing the shorter, more energetic wavelengths (blue through UV) of light and eventually being degraded by their energies. Ever notice how the red on road signs is very quick to fade with extended exposure to sunlight compared with blue and white.

i found an Ebay shop in hongkong that will print it and ship it cheaper than a local sign shop was willing to sell me offcuts

I was told by a plastic welder who manufactures custom items for commercial and marine use that the black PVC and polyethylene last outdoors in the sun and that the white PVC & poly deteriorated quickly by the penetration of the sunlight threw the white color damaging the plastic,
causing it to be brittle and break easily.
I wonder if the white paints condition, not the color, is more subjected to sunlight damage by its light passing white pigment.

It dawned on me that NASA makes everything white so they can find it again !
or
could be "we never get to "SEE" the black stealth stuff"

White pigment doesn't pass light. it reflects light. If it passed light, it would be called translucent.

There are several ways to impart UV resistance to PVC and polyethylene. The cheapest way is to add carbon black to the plastic. Carbon black absorbs UV and converts it to heat. A more expensive way to protect from UV is to add titanium dioxide to the plastic. Titanium dioxide (also used in sunscreen lotion), reflects the UV, but doesn't provide quite as much UV protection in plastics as carbon black, since the UV can do damage on its way in and on its reflected way back out of the plastic. A third way that can be used to protect polyethylene is to cross link its polyethylene chains, which is how they get the clear greenhouse films to last 4+ years in the sun.

Most of what NASA sends out of earth orbit isn't ever coming back, so they're not expecting to have to try to visually find it again. So that's not the reason they are white.

Depends. A white substance may reflect from the surface, or (as with some plastics) the light may penetrate some distance before reflecting.

There's also the question of what "color" the white is in the UV spectrum. Consider flowers: bees see in the ultraviolet, so a flower that appears to be white or solid color to human vision often looks much different in UV. See for instance Flowers in Ultra-Violet

I've been thinking about it, but this thread pushed me over the edge. :D
http://img.photobucket.com/albums/09.../whiteroof.jpg

I'm just waiting for California to ban all non-white cars in a bid to single-handedly solve global warming.

-

I'd author the bill myself, if anyone is interested in supporting it... :D

Has anyone considered gluing a sheet of Mylar to the roof?

When A/C was still restricted to higher-end vehicles, white roofs were extremely popular in some overseas markets, from Central and South America to Africa and Southeast Asia.
http://1.bp.blogspot.com/-iApQBmSh-J...Imagem0243.jpg
http://3.bp.blogspot.com/-t5H4HFL7BI.../Imagen061.jpg

Even the DKW range, developed in Germany, had to get into the trend when it was made in Brazil. It's almost impossible to find a Brazilian DKW which didn't have a white roof...
http://2.bp.blogspot.com/-0UoOdZAtIQ...Imagem0416.jpg
http://3.bp.blogspot.com/-hDmIBJwtm5...Imagem1249.jpg

http://4.bp.blogspot.com/-yfhMiDYe9l...eto+branco.jpg
Sometimes I wonder if this trend could come back...
http://3.bp.blogspot.com/-VjlnlqAU26.../Photo0823.jpg

The Definitive Study
 

0.5 mpg better fuel economy found with silver compact car with air conditioner in warm climate: Silver and white cars are cooler, says study

Wait, how is 0.44 MPG 2% of a Civic's fuel economy? :)

I am sitting at 45 MPG lifetime on my Civic, so if I painted my car silver, I would achieve 45.9 MPG?

Except... I do not use my air conditioner! :D

I do not drive with the windows open, either. I could smell better...

I am pretty sure that this has been discussed in another thread. But anyway, I decided not to do any painting in the end. The reason was the realization that once the car is moving the aerodynamic flow of air cools all the cars about equally. My car is black. Parked the roof gets wicked hot. Go for a drive and it cools down pretty fast. I doubt a while roof is a lot cooler when in motion. This means metalized or ceramic dark tint is your better cabin-cooling strategy, and I have already had that for four years (got lifetime warranty).

The assumption, of course, is that absolutely everyone behaves exactly as their simulations predict.

I love this idea and have considered going this route on the truck. It never had AC so anything to cool it off is good.

Moving, the difference is less, but it's still there, in my experience.

What tint are you using? I'm running untinted windows still and am looking for a street legal window tint.

film types
 

I got metalized tint and as dark as lawful. It's limo dark. My wife has ceramic tint in her car. 4 years and no fading, bubbling, peeling. Great stuff. Check out the types here: Johnson Window Films, Dealer Resource Center

James

Wait, so you mean I've been doing it wrong?

http://ecomodder.com/forum/attachmen...1&d=1437017727

I like the white roof on your ' Cruiser a lot! I have an old (1995) outstandingly clean "Box Jeep" - Cherokee with 4 liter 6 and stick shift. The old 4.0 is designed to run warm, and I live in Colorado, so if it's hot I am jeeping in the wrong place! All this adds up to: I removed the Jeep Cherokee's air conditioning radiator from in front of the engine radiator. An immediate drop in operating temperature has been my reward. Now I plan to paint my roof white (very carefully, it's a clean Jeep...) like your ' Cruiser!

White roofs look awesome on many vehicles - your ' Cruiser, the Mini Cooper, and my Jeep Cherokee being just three.

I only just noticed how cool post 26 in this thread was: http://ecomodder.com/forum/showthrea...tml#post361468

Necroing this to say the type of white pigment is important:

IIRC
This guy, who does the research, then makes it DIY, found that Calcium Carbonate (Whitewash) pigment was best at reflecting the IR light that heated surfaces and made paint:
https://www.youtube.com/watch?v=N3bJnKmeNJY&t=163s

He provides links to the science in the comments.


That's not going to work on dashboards reflecting in the windscreen and disrupting your view of the road, so thx for the window film info.

'infrared'
 

I believe that the 'process' involves reflecting as much of the visible and ultraviolet back towards space, before it ever has an opportunity to transform into long-wave infrared after is strikes the surface.
Flat-white is best for that. Not any 'glossy' surface.
And even with the best albedo, given enough 'time' in the sun, the car will reach the same temp. as a 'black' car. It just takes longer.
And something not mentioned is 'latent' load.
Relative humidity is often the 'reason' why air conditioning is used. It's not just the dry-bulb temperature.
Around 'local' dewpoint temperature, air is 'saturated' with water vapor. It's impossible for perspiration on your body to 'evaporate', which, otherwise could make one comfortable.
Where I live, 80-degrees can feel like 104! And it can kill you.
I agree that reducing the solar load can reduce energy consumption, but it must be taken within the context of human factors and human physiology.
'Cooling', without dehumidification only 'INCREASES' relative humidity, and the Heat-Index. It's why we have 'refrigerated-air'.

aerohead does not believe in the Atmospheric Window.

er... The vid's good because this guy delved into the science and engineered a paint that works.
so... watch it, or not..