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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

#241

Post by readflaggedcomm »

robomartin wrote: post #144

Yeah, no, 98% percent reflectance paint has been available for, I don’t know, 30 years. I was using it about 15 years ago for a product that required high optical efficiency. The problem with such paints or coatings is that they don’t perform well over time outside of a clean room environment. On a roof this 98% would likely only exist for 1.2 microseconds. Dust, dirt, aging an bird shit will make sure of that. Clima…

I agree. But theoretically, if the paint shed or repelled dirt very well, it could outperform something with near the same reflectivity. But the article doesn't acknowledge titanium dioxide paints with the same theoretic reflectivity, so I have to assume it won't perform any better than existing products.

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

#242

Post by asah »

dejj wrote: post #2

Also: Black 3.0, the purchasable variant of Vantablack For sale at: https://www.culturehustleusa.com/

I used Black 2.0 and 3.0 to make an distracting little sill disappear. 2.0 was easier to use, but 3.0 is really really black.

before: https://photos.app.goo.gl/usBMEYDRgykc2bni6

after: https://photos.app.goo.gl/89cyApVzncXWcHYt5 https://photos.app.goo.gl/zxnGMrcUrodM78Lq8

night (really just gone): https://photos.app.goo.gl/La1KNutxn3PhSEAg8

closeup: https://photos.app.goo.gl/uQ3d5oRYtnB3Tfzh8

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

#244

Post by Godel_unicode »

legulere wrote: post #218
spiritplumber wrote: post #215

Earlier quoted context omitted.

Finding a commercial use for polar bear fur is awesome, actually. It would ensure that polar bears never go extinct.

Like how elephants were greatly reduced in numbers to make billiard balls?

Or whales, or rhinos, or sharks, or beaver, or buffalo...

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

#247

Post by nordsieck »

rpz wrote: post #246

I wonder if anybody has tried using mirrors instead of white paint for cool roofs. I also wonder if some arrangement of perfect mirrors could act as a sort of light storage mechanism (battery)

> I wonder if anybody has tried using mirrors instead of white paint for cool roofs.

From rockets, the reason white paint is often higher performance is that, while it has lower reflectivity than a mirrored surface, it has higher emissivity.

Between the performance, the lower cost of white paint as opposed to a mirror finish, and the curb appeal, I doubt more than a few people have clad their house in mirrors.

> I also wonder if some arrangement of perfect mirrors could act as a sort of light storage mechanism (battery)

I don't know, but I suspect that mirrors just aren't reflective enough for this to be practical.

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

#249

Post by ping_pong »

orev wrote: post #203
ping_pong wrote: post #199

This sounds like a waste of energy to me. I think all roofs should be covered in solar power generating equipment. Reflecting all that sun energy back into the air just heats up our planet, better to convert that into electricity

Light turns into heat when it is absorbed by a material. Reflecting it back into the air sends it (and the heat) back out into space, and since air is mostly clear it does not get absorbed so doesn’t “heat up the planet”, at least not in any significant way. Sure, using the energy for solar would be nice too, but that’s far more expensive per square meter, so paint is a fine solution that’s cheap.

I guess everyone is forgetting about the "Greenhouse effect" where that theoreticaly light/heat is reflected back into the Earth? Or do you not believe in the Greenhouse effect?

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

#250

Post by renox »

clairity wrote: post #220
korethr wrote: post #204

Earlier quoted context omitted.

The big box stores employees at the paint counter seem as ignorant as a novice about the vagaries of application most likely because they themselves are novices. They may know quite a bit about colors and matching and how to work the mixing machines, but they probably don't have much more experience painting than the average homeowner. That knowledge comes more from doing, whether its a handful of projects as a homeo…

yes, there's no experience or incentive for better knowledge in big box stores unfortunately. i've moved on to buying from a local paint specialty store, which is owned by a family that i believe is/was in the construction/painting business. they cater mainly to contractors but also sell to the wider public. oh, and yeah, paint and primer in one does neither job very well.

Yep, been there too: paint is really something where you want to avoid the big shop and goes to speciality stores instead (paint peeling from the wall? Color changing after a year? Done and done --> switched to a dedicated paint store == no more issues, the paint itself is more expensive sure but the result is stable)
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