Imagine a white paint that keeps buildings and cars cool. The data must be independently confirmed.
The whitest paint is here – and it’s the coolest. Literally. - Purdue University News
The whitest paint is here – and it’s the coolest. Literally. - Purdue University News
The highly reflective white paint is based on inexpensive calcium carbonate as found in shells, limestone and chalk.
However, it remains to be seen how white will it stay when subjected to the elements.
The world'''s whitest white is here—and it'''s coming to a roof near you
However, it remains to be seen how white will it stay when subjected to the elements.
The world'''s whitest white is here—and it'''s coming to a roof near you
I feel the effects will be marginal. White paint already reflects most of the heat. And if it gets heated up slightly it will more likely loose to the surrounding rather than penetrate the wall and into the interior.
You will get more heating load from your windows, which the killer. Also ambient temperature is very high and will still need air conditioning. My 2cents based on someone who lives in the tropics.
Oon
You will get more heating load from your windows, which the killer. Also ambient temperature is very high and will still need air conditioning. My 2cents based on someone who lives in the tropics.
Oon
We get a cooling paint here, to be applied annually to the roof. Acts as a sealant for minor gaps too.
Mostly lime (Calcium Carbonate) and PVA emulsion, a little white cement.
Mostly lime (Calcium Carbonate) and PVA emulsion, a little white cement.
Just read the Purdue brochure/Ad.
Not bad but sounds slightly optimistic and even counter Science in some points, go figure.
That they patented it and are trying to sell it to some investors may cloud the issue a little.
All it can do is reflect more infrared , nothing further unless we appeal to Magic; some statements are hard to swallow.
Such as:
If anything, *black* would be better, because it would radiate more.
That's why we paint/anodize our heat sinks black.
Oh, and it claims to use Barium Sulfate.
Nothing new under the Sun (pun intended 😉 ) , I am a Photographer and have used Baryte (coated) Paper since forever, in fact invented in the 1880´s or so.
Not bad but sounds slightly optimistic and even counter Science in some points, go figure.
That they patented it and are trying to sell it to some investors may cloud the issue a little.
All it can do is reflect more infrared , nothing further unless we appeal to Magic; some statements are hard to swallow.
Such as:
How? By which mechanism?
If anything, *black* would be better, because it would radiate more.
That's why we paint/anodize our heat sinks black.
Irrelevant.
Oh, and it claims to use Barium Sulfate.
Nothing new under the Sun (pun intended 😉 ) , I am a Photographer and have used Baryte (coated) Paper since forever, in fact invented in the 1880´s or so.
When I was attempting to get brighter white paint for a transportation project some 15 years ago, the chem engineers kept reminding me that they still had to leave room for the binders and such that actually make it “paint”, is a lot more than just pigments…
Somebody patented turmeric in the USA, the Indian government had it thrown out on the grounds of native (traditional) knowledge.
This is bad, a university making wild claims, removes a little of the respect for the institution.
Some of these cooling paints may be mixed with SBL (water proofing latex) and white cement for better adhesion and crack sealing. They usually come off in the winter, so every year the user cleans with a wire brush, and applies a new coat.
Cheap, about $2 for 5 kilos, enough for 600 sq. feet of tiles. This price is without the added latex and white cement.
This is bad, a university making wild claims, removes a little of the respect for the institution.
Some of these cooling paints may be mixed with SBL (water proofing latex) and white cement for better adhesion and crack sealing. They usually come off in the winter, so every year the user cleans with a wire brush, and applies a new coat.
Cheap, about $2 for 5 kilos, enough for 600 sq. feet of tiles. This price is without the added latex and white cement.
That's the old news, the newer news is according to the link in post #1 states:
"Their previous ultra-white paint was a formulation made of calcium carbonate, an earth-abundant compound commonly found in rocks and seashells."
also...
"What makes the whitest paint so white
Two features give the paint its extreme whiteness. One is the paint’s very high concentration of a chemical compound called barium sulfate, which is also used to make photo paper and cosmetics white.
...
The second feature is that the barium sulfate particles are all different sizes in the paint. How much each particle scatters light depends on its size, so a wider range of particle sizes allows the paint to scatter more of the light spectrum from the sun.
"
and...
"The new whitest paint formulation reflects up to 98.1% of sunlight – compared with the 95.5% of sunlight reflected by the researchers’ previous ultra-white paint"
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Here in Australia, Dulux were fined $400K for misleading cooling paint claims.
Dulux to pay $400,000 for misleading cooling paint claims | ACCC
Dulux to pay $400,000 for misleading cooling paint claims | ACCC
Cool!!!!! 😀 (ooops!!!! ... now I will be fined 😱 )
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Serious: your post sums it all.
And in any case, I bet mirror polished Aluminum reflects better than any "white" .... or Thermos flasks bottles would be painted white instead.
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Serious: your post sums it all.
And in any case, I bet mirror polished Aluminum reflects better than any "white" .... or Thermos flasks bottles would be painted white instead.
I thought Titanium Dioxide was the whitest material.
Also, aluminum flakes in paint, sometimes called pearl pigments, used in cars (among other things), can be very reflective too.
Also, aluminum flakes in paint, sometimes called pearl pigments, used in cars (among other things), can be very reflective too.
But.. Barium Sulphate and the various flavours of Calcium Carbonates have been used as 'cheap' extenders in white paint forever - because the 'better' Titanium Dioxides are expensive.
I cant see anything new here.
I cant see anything new here.
People have been painting their houses white in hot countries for some time.
Recently the blackest of blacks and the whitest of whites paints and coatings are being developed.
With the white, attention to how the specific paint reflects infrared is being considered.
This is just development, not revolution. Putting the tech into wider use would be smewht revolutionary.
dave
Recently the blackest of blacks and the whitest of whites paints and coatings are being developed.
With the white, attention to how the specific paint reflects infrared is being considered.
This is just development, not revolution. Putting the tech into wider use would be smewht revolutionary.
dave
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nor saves any dolphin !!!!!!!
Does wearing a Greta Thunberg T shirt apply?
At least a text only one, with "How you Dare!!!" silkscreened front and back .... with 98.1% reflective Barium Sulphate pigmented Textile Ink of course.
I was when working a general builder and painting was part of it. I never encountered a really white paint in the UK, there was always a hint of rose, green or blue but when I went to live in southern Spain they did have a real white wall paint.
As to white reflecting heat yes that is true. One day I was visiting a nearby village, looking at possible buys of derelict houses. There was a high spot which had a small chapel with a small car park. It had a low wall surrounding it part of which was capped with red tiles and part had been rendered and painted in this dead white. The temperature was 41C, I touched one of the red tiles, if i had left my fingers on it i would have been burned - you could easily cook food on these tiles. Touching the painted rendering - it was only warm.
The continued use of slate and tiles as roof coverings is all about the 'inertia effect'. It has become the 'fashion' now in a lot of European countries to use black/dark grey aluminium for windows/doors and plastic fencing - absolutely insane and because it is fashionable the stupid punters cough up.
As to white reflecting heat yes that is true. One day I was visiting a nearby village, looking at possible buys of derelict houses. There was a high spot which had a small chapel with a small car park. It had a low wall surrounding it part of which was capped with red tiles and part had been rendered and painted in this dead white. The temperature was 41C, I touched one of the red tiles, if i had left my fingers on it i would have been burned - you could easily cook food on these tiles. Touching the painted rendering - it was only warm.
The continued use of slate and tiles as roof coverings is all about the 'inertia effect'. It has become the 'fashion' now in a lot of European countries to use black/dark grey aluminium for windows/doors and plastic fencing - absolutely insane and because it is fashionable the stupid punters cough up.