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'Whitest ever' paint reflects 98% of sunlight

bbc.com

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Re: 'Whitest ever' paint reflects 98% of sunlight

#21

Post by rtkwe »

SamBam wrote: post #11

I assume this could be useful to shield something in space with extremely specific temperature tolerances. I'm not sure about the suggestion that people are going to paint their roofs with it. People already have the opportunity to paint their roofs with cheap white paint which would provide nearly all the benefits this would, and still choose not to do it.

White roofs don’t look great which is why I think they’re largely relegated to commercial buildings instead of residential ones. They get dirty fast, are super bright and don’t fit with the traditional look for houses. On commercial flat top roofs they are hidden so it doesn’t matter if they’re blindingly bright or stained because they’re not visible.

Re: 'Whitest ever' paint reflects 98% of sunlight

#22

Post by ebiester »

SamBam wrote: post #11

I assume this could be useful to shield something in space with extremely specific temperature tolerances. I'm not sure about the suggestion that people are going to paint their roofs with it. People already have the opportunity to paint their roofs with cheap white paint which would provide nearly all the benefits this would, and still choose not to do it.

What we really need is white paint in the summer, black paint in the winter - reversible roofs, if you will.

That said, in the desert southwest and many places in the world, white roofs are common. I wish it were more common in the southeast...

Re: 'Whitest ever' paint reflects 98% of sunlight

#23

Post by cosmodisk »

cyberlab wrote: post #4

Someone needs to compile a list of all this fringe tech that I see popping up in my feeds, almost daily now. I know there are techpress blogs that pump out articles like this, but there doesn't seem to be an authoritative compendium of such tech anywhere on the net. I could curate this by hand with 3 hours of free time and some Red Bull I suppose. The reason I want this is because we seem to be swimming in innovation…

Such a good idea! There's so much stuff being invented, some of it outright insane and yet it's almost impossible to find anything, unless you are very knowledgeable in a particular field.

For instance,I've been subscribing to materialdistrict.com for years and some materials they showcase are simply mind boggling.

Re: 'Whitest ever' paint reflects 98% of sunlight

#24

Post by bryanrasmussen »

rtkwe wrote: post #21
SamBam wrote: post #11

I assume this could be useful to shield something in space with extremely specific temperature tolerances. I'm not sure about the suggestion that people are going to paint their roofs with it. People already have the opportunity to paint their roofs with cheap white paint which would provide nearly all the benefits this would, and still choose not to do it.

White roofs don’t look great which is why I think they’re largely relegated to commercial buildings instead of residential ones. They get dirty fast, are super bright and don’t fit with the traditional look for houses. On commercial flat top roofs they are hidden so it doesn’t matter if they’re blindingly bright or stained because they’re not visible.

>They get dirty fast

do they get dirty fast in both humid and not humid climates? I would think in not humid, dry climates it might be more useful?

Re: 'Whitest ever' paint reflects 98% of sunlight

#25

Post by Xplune13 »

cyberlab wrote: post #4

Someone needs to compile a list of all this fringe tech that I see popping up in my feeds, almost daily now. I know there are techpress blogs that pump out articles like this, but there doesn't seem to be an authoritative compendium of such tech anywhere on the net. I could curate this by hand with 3 hours of free time and some Red Bull I suppose. The reason I want this is because we seem to be swimming in innovation…

I agree. Such a compendium would be great and more so if that would be the only place where we can get the information about inventions and innovations.

Re: 'Whitest ever' paint reflects 98% of sunlight

#26

Post by frabert »

bryanrasmussen wrote: post #24
rtkwe wrote: post #21

Earlier quoted context omitted.

White roofs don’t look great which is why I think they’re largely relegated to commercial buildings instead of residential ones. They get dirty fast, are super bright and don’t fit with the traditional look for houses. On commercial flat top roofs they are hidden so it doesn’t matter if they’re blindingly bright or stained because they’re not visible.

>They get dirty fast do they get dirty fast in both humid and not humid climates? I would think in not humid, dry climates it might be more useful?

Dust would settle on them despite of humidity levels I think

Re: 'Whitest ever' paint reflects 98% of sunlight

#28

Post by beauzero »

SamBam wrote: post #11

I assume this could be useful to shield something in space with extremely specific temperature tolerances. I'm not sure about the suggestion that people are going to paint their roofs with it. People already have the opportunity to paint their roofs with cheap white paint which would provide nearly all the benefits this would, and still choose not to do it.

There are even tax benefits for doing this in the USA. https://www.energystar.gov/about/federal_tax_credits/roofs_m... We decided to not use shingles on our new roof but go with silver galvalum. Galvalum does not provide the initial reflectivity but over a 5 year period shingles lose much of their reflectivity https://homeenergysaver.lbl.gov/consumer/help-popup/content/... https://web.ornl.gov/sci/buildings/tools/cool-roof/ ...there are many other resources out there. It made a huge difference in our home in rural Georgia.

Re: 'Whitest ever' paint reflects 98% of sunlight

#29

Post by Arnt »

buran77 wrote: post #15
jbverschoor wrote: post #10

Can someone explain the difference between this and a mirror? A mirror reflects also something like 98%, right?

I would expect it's twofold. This paint acts like a "diffuse mirror" so doesn't create any bright spots like specular reflection. This is great particularly in cities where every building would become a giant mirror. On the other hand a mirror finish is harder to achieve on rough surfaces that the paint would presumably be used on.

Adding:

Mirrors don't have to reflect very much, they have to reflect as a picture. That's why one-way mirrors work — people generally don't notice that the light mirrored is much less than 100%. White paint is free to reflect the photons in any direction, so that >98% is a harsher requirement on the share of incoming photons, but a laxer requirement on the photons' direction.

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