Solar reflective auto paint

[serialk11r]

Note that 1% of the earth's surface is a metric s***load.

But yea the white painted surface is actually cooler than the air around it is correct (weather dependent though, doesn't work if the sky isn't clear). The high emissivity is one reason why white is cooler than even a very reflective silver. The silver just reflects most of the heat, while the white actively radiates if its temperature is higher than the surroundings.

[freebeard]

Note that 1% of the earth's surface is a metric s***load.

No more absurd than the resultant, not reducing the rate of increase but rolling back global heating to date.

(weather dependent though, doesn't work if the sky isn't clear)

I understood that CO2 and water vapor are transparent at the target frequencies.

[aerohead]

Originally Posted by freebeard

No more absurd than the resultant, not reducing the rate of increase but rolling back global heating to date.



I understood that CO2 and water vapor are transparent at the target frequencies.

It wouldn't matter if that were 100% fact.
The 'actual' energy balance must take into account, the presence of all the other tropospheric greenhouse gases which are NOT transparent to those frequencies.

[freebeard]

The Ultrabright pigments (Permalink #37) require a thick coating to be effective. Compare this:

phys.org/news/2023-03: Researchers create world's first energy-saving paint—inspired by butterflies

Based on such bio-inspirations, Chanda's research group innovated a plasmonic paint, which utilizes nanoscale structural arrangement of colorless materials—aluminum and aluminum oxide—instead of pigments to create colors.
....
Such structural colors are environmentally friendly as they only use metals and oxides, unlike present pigment-based colors that use artificially synthesized molecules.The researchers have combined their structural color flakes with a commercial binder to form long-lasting paints of all colors.

"Normal color fades because pigment loses its ability to absorb photons," Chanda says. "Here, we're not limited by that phenomenon. Once we paint something with structural color, it should stay for centuries."

Additionally, because plasmonic paint reflects the entire infrared spectrum, less heat is absorbed by the paint, resulting in the underneath surface staying 25 to 30 degrees Fahrenheit cooler than it would if it were covered with standard commercial paint, the researcher says.

"Over 10% of total electricity in the U.S. goes toward air conditioner usage," Chanda says. "The temperature difference plasmonic paint promises would lead to significant energy savings. Using less electricity for cooling would also cut down carbon dioxide emissions, lessening global warming."

Plasmonic paint is also extremely lightweight, the researcher says.

This is due to the paint's large area-to-thickness ratio, with full coloration achieved at a paint thickness of only 150 nanometers, making it the lightest paint in the world, Chanda says.

[SimplifyAndAddCoffee]

Figured I'd share in this thread:

I initially repainted the roof of my van with a bright white marine topside paint for durability and high heat reflectivity. It made an immediate difference. I have since used a rubberized coating that goes on thick to both seal and protect. In both cases I did the research first to find pigments and formulations that provided the best IR rejection.

Then I added the solar panels, which are enough to run a 14k btu A/C in the back which effectively negates the tin-can-in-the-sun effect. Very effective.

[freebeard]

The amazing part is that you could post a picture with only three posts in total.

[SimplifyAndAddCoffee]

Originally Posted by freebeard

The amazing part is that you could post a picture with only three posts in total.

I guess I'm just special!

[cRiPpLe_rOoStEr]

Originally Posted by SimplifyAndAddCoffee

I have since used a rubberized coating that goes on thick to both seal and protect.

Does it also decrease noise from the rain while you sleep inside the van? I remember a chemical industry claiming its rubberized paints provided some degree of sound deadening when applied to rooftops.

[freebeard]

Update: This is only a first part, but Nighthawkinlight has extended his investigation to creating particles that reflect in specific wavelengths by adjusting ratios of the reactants in solution.

making opals for free air conditioning

What's possible? An opalescent window tint?

[freebeard]

Another update:

The record for reflectance has been moved to 104%. Phys.org four hourrs ago:

phys.org/: Researchers claim photoluminescent aerogel has a visible light reflectance of 104%

In this new study, the team in China reports that a passive radiative cooling material reflects more light than it receives due to its photoluminescence properties.

With photoluminescence, molecules absorb photons in the visible region and then excite their electrons to a higher state, resulting in light emission. Thus, if a material were to reflect 100% of the light that strikes it and additionally had photoluminescence, it could, in theory, reflect more light than it received.

To create such a material, the research team added freeze-dried salmon sperm DNA to a sample of gelatin. They allowed it to sublimate, leaving behind a layered aerogel that was highly compressed. The research team explains that it is held together via hydrogen bonds between phosphates in the DNA and amino acids in the gelatin.

So will it work (some might ask) with vaccinated Salmon sperm?