a paint to isolate from heat

[look]

this article give me an idea to isolate part of the house from heat.

the title of the article is; Purdue university the whitest paint is here and it's the coolest. Literally.

why i don't place the link? because i could't copy. I think with the title you can find it using google search.

they add barium sulfate to the paint.

i think to buy a white paint and to add barium sulphate.

But it seems to good to be true. I recognize.

[Lootman]

I once chose a paint based on its high reflectivity. There is actually a technical term for it: albedo. Although that term is more commonly used for solar reflection in astronomy.

[Mike4]

this article give me an idea to isolate part of the house from heat.

the title of the article is; Purdue university the whitest paint is here and it's the coolest. Literally.

why i don't place the link? because i could't copy. I think with the title you can find it using google search.

they add barium sulfate to the paint.

i think to buy a white paint and to add barium sulphate.

But it seems to good to be true. I recognize.

Not sure why you had a problem. Although all those dots in the URL don't seem legitimate.

https://www.purdue.edu/newsroom/release ... ally..html

Even so, it strikes me as just more twaddle.

[servodude]

this article give me an idea to isolate part of the house from heat.

the title of the article is; Purdue university the whitest paint is here and it's the coolest. Literally.

why i don't place the link? because i could't copy. I think with the title you can find it using google search.

they add barium sulfate to the paint.

i think to buy a white paint and to add barium sulphate.

But it seems to good to be true. I recognize.

Not sure why you had a problem. Although all those dots in the URL don't seem legitimate.

https://www.purdue.edu/newsroom/release ... ally..html

Even so, it strikes me as just more twaddle.

Even if that were the case you might be able to get Anish Kapoor interested

[Mike4]

this article give me an idea to isolate part of the house from heat.

the title of the article is; Purdue university the whitest paint is here and it's the coolest. Literally.

why i don't place the link? because i could't copy. I think with the title you can find it using google search.

they add barium sulfate to the paint.

i think to buy a white paint and to add barium sulphate.

But it seems to good to be true. I recognize.

Not sure why you had a problem. Although all those dots in the URL don't seem legitimate.

https://www.purdue.edu/newsroom/release ... ally..html

Even so, it strikes me as just more twaddle.

Even if that were the case you might be able to get Anish Kapoor interested

"Sir Anish Mikhail Kapoor is a British-Indian sculptor specializing in installation art and conceptual art." according to his website.

I just LURVE what Sir Grayson Perry said about conceptual art in one of his Reith Lectures. "You don't have to like it all". I so used to worry about that, and now I don't have to. Thank you Sir Grayson!

[servodude]

this article give me an idea to isolate part of the house from heat.

the title of the article is; Purdue university the whitest paint is here and it's the coolest. Literally.

why i don't place the link? because i could't copy. I think with the title you can find it using google search.

they add barium sulfate to the paint.

i think to buy a white paint and to add barium sulphate.

But it seems to good to be true. I recognize.

Not sure why you had a problem. Although all those dots in the URL don't seem legitimate.

https://www.purdue.edu/newsroom/release ... ally..html

Even so, it strikes me as just more twaddle.

Even if that were the case you might be able to get Anish Kapoor interested

"Sir Anish Mikhail Kapoor is a British-Indian sculptor specializing in installation art and conceptual art." according to his website.

I just LURVE what Sir Grayson Perry said about conceptual art in one of his Reith Lectures. "You don't have to like it all". I so used to worry about that, and now I don't have to. Thank you Sir Grayson!

I just thought he might like the whitest paint to go with his blackest black
https://www.thecollector.com/vantablack-anish-kapoor-stuart-semple-controversy/

[odysseus2000]

this article give me an idea to isolate part of the house from heat.

the title of the article is; Purdue university the whitest paint is here and it's the coolest. Literally.

why i don't place the link? because i could't copy. I think with the title you can find it using google search.

they add barium sulfate to the paint.

i think to buy a white paint and to add barium sulphate.

But it seems to good to be true. I recognize.

When you say heat, do you mean light?

Regards,

[servodude]

this article give me an idea to isolate part of the house from heat.

the title of the article is; Purdue university the whitest paint is here and it's the coolest. Literally.

why i don't place the link? because i could't copy. I think with the title you can find it using google search.

they add barium sulfate to the paint.

i think to buy a white paint and to add barium sulphate.

But it seems to good to be true. I recognize.

When you say heat, do you mean light?

Regards,

It's the same spectrum
with very similar behaviour across it when you start playing with optical manipulation - e.g. it's not the light that burns the ants through a magnifying glass
- or Santorini looks as it does for more than simply aesthetic reasons

-sd

[odysseus2000]

It's the same spectrum
with very similar behaviour across it when you start playing with optical manipulation - e.g. it's not the light that burns the ants through a magnifying glass
- or Santorini looks as it does for more than simply aesthetic reasons

-sd

It depends what you want to do.

If you are trying to cool something then painting it black increases the emissions, but will also increase the absorption if it is subject to heat and there are trade off. People who live in deserts often dress in black not white.

If you want to reflect sun light then a mirror is a good surface.

In all cases its the electromagnetic spectrum that you are dealing. For optical light this is about 400 to 700 nm.

Ultra violet often means from about 100 to 400 nm and infra red is greater than 700 nm.

Regards,

[look]

this article give me an idea to isolate part of the house from heat.

the title of the article is; Purdue university the whitest paint is here and it's the coolest. Literally.

why i don't place the link? because i could't copy. I think with the title you can find it using google search.

they add barium sulfate to the paint.

i think to buy a white paint and to add barium sulphate.

But it seems to good to be true. I recognize.

When you say heat, do you mean light?

Regards,

It's the same spectrum
with very similar behaviour across it when you start playing with optical manipulation - e.g. it's not the light that burns the ants through a magnifying glass
- or Santorini looks as it does for more than simply aesthetic reasons

-sd

Servodude, the heat is caused mainly by infrared rays, and the paint reflects infrared rays too. So, when i say heat, it's heat.

[servodude]

It's the same spectrum
with very similar behaviour across it when you start playing with optical manipulation - e.g. it's not the light that burns the ants through a magnifying glass
- or Santorini looks as it does for more than simply aesthetic reasons

-sd

It depends what you want to do.

If you are trying to cool something then painting it black increases the emissions, but will also increase the absorption if it is subject to heat and there are trade off. People who live in deserts often dress in black not white.

If you want to reflect sun light then a mirror is a good surface.

In all cases its the electromagnetic spectrum that you are dealing. For optical light this is about 400 to 700 nm.

Ultra violet often means from about 100 to 400 nm and infra red is greater than 700 nm.

Regards,

The trick with Bedouin robes is their thickness in addition to the colour (thin black clothes would be worse than thin white clothing)
- they are designed to absorb heat and create convection under them as that dissapates before it reaches the wearer
- what they need next is to capture moisture and circulate it using pumps driven by the action of walking - and lots of melange

-sd

[servodude]

this article give me an idea to isolate part of the house from heat.

the title of the article is; Purdue university the whitest paint is here and it's the coolest. Literally.

why i don't place the link? because i could't copy. I think with the title you can find it using google search.

they add barium sulfate to the paint.

i think to buy a white paint and to add barium sulphate.

But it seems to good to be true. I recognize.

When you say heat, do you mean light?

Regards,

It's the same spectrum
with very similar behaviour across it when you start playing with optical manipulation - e.g. it's not the light that burns the ants through a magnifying glass
- or Santorini looks as it does for more than simply aesthetic reasons

-sd

Servodude, the heat is caused mainly by infrared rays, and the paint reflects infrared rays too. So, when i say heat, it's heat.

Indeed

Interestingly when I cut my teeth on the my first engineering role it was closing the servo loop around the mechanics of CD equipment - the optical part of which is an infra-red laser @ 780nm (the red you might have seen in one is just energy spilling over - the dangerous bit to your eyes is the stuff you can't see)

It was quite an eye opener (though they were covered in green googles) that you could do everything with the invisible laser than you could do on a normal laser bench (you just couldn't see it - of if you did there was somethign up with your diode)

-sd

[odysseus2000]

Look

Servodude, the heat is caused mainly by infrared rays, and the paint reflects infrared rays too. So, when i say heat, it's heat.

Infrared rays are usually classed as radiant heat to distinguish this form of warming from convected heat.

It depends on what you are trying to stop. If its sunlight then normally one would put some kind of insulation under the top reflective surface. For folk who had their house cavity walls filled with insulator, the usual grumble is that it did make the house warmer in winter which they wanted but it makes the house much cooler in summer which often they don't want.

Regards,

[9873210]

It's the same spectrum

In all cases its the electromagnetic spectrum that you are dealing. For optical light this is about 400 to 700 nm.

Ultra violet often means from about 100 to 400 nm and infra red is greater than 700 nm.

While they are all electromagnetic waves materials can respond quite differently to different wavelengths. That is why things have colours.

Engineers can and do design paints and other substances to have different absorption at different wavelengths. Coloured paints are a notable example. Another is low-e coatings on glass, they transmit most visible light while reflecting most of the UV and infrared. You can see through the film but much of the incoming energy is reflected.

If this is the same paint I have previously read about and IIUC, it is designed to be highly reflective at shorter wavelengths (including visible and short IR) where most of the incoming solar energy is, but highly emissive (which also means low reflectivity) at longer wavelengths that can radiate into the cold of space. The claim is not simply that it does not absorb energy, but that it can transmit more energy than it absorbs even in direct sunlight, making it better than a perfect reflector.

[servodude]

It's the same spectrum

In all cases its the electromagnetic spectrum that you are dealing. For optical light this is about 400 to 700 nm.

Ultra violet often means from about 100 to 400 nm and infra red is greater than 700 nm.

While they are all electromagnetic waves materials can respond quite differently to different wavelengths. That is why things have colours.

Engineers can and do design paints and other substances to have different absorption at different wavelengths. Coloured paints are a notable example. Another is low-e coatings on glass, they transmit most visible light while reflecting most of the UV and infrared. You can see through the film but much of the incoming energy is reflected.

If this is the same paint I have previously read about and IIUC, it is designed to be highly reflective at shorter wavelengths (including visible and short IR) where most of the incoming solar energy is, but highly emissive (which also means low reflectivity) at longer wavelengths that can radiate into the cold of space. The claim is not simply that it does not absorb energy, but that it can transmit more energy than it absorbs even in direct sunlight, making it better than a perfect reflector.

That does sound fascinating - I'll try and have a read about it.
I thought a perfect relector did not absorb or transmit anything (but this would be vague flashbacks to optical transmission lectures and stuff about total internal reflection)

[GrahamPlatt]

Other uses of light…

Far UV

https://www.nature.com/articles/s41598-020-67211-2

https://www.rfsafe.com/207-222-nm-uvc-l ... -covid-19/

[ReformedCharacter]

this article give me an idea to isolate part of the house from heat.

the title of the article is; Purdue university the whitest paint is here and it's the coolest. Literally.

why i don't place the link? because i could't copy. I think with the title you can find it using google search.

they add barium sulfate to the paint.

i think to buy a white paint and to add barium sulphate.

But it seems to good to be true. I recognize.

DIY cooling paint, using Barium Sulphate - How To Make Infrared Cooling Paint (Electricity Free Air Conditioning):

https://www.youtube.com/watch?v=N3bJnKmeNJY

RC

[odysseus2000]

servodude
Engineers can and do design paints and other substances to have different absorption at different wavelengths. Coloured paints are a notable example. Another is low-e coatings on glass, they transmit most visible light while reflecting most of the UV and infrared. You can see through the film but much of the incoming energy is reflected.

E coatings are advertised as working both ways, reflecting infra red from the inside back into the room, but I am not sure how much of this is marketing. The last windows we had installed only had the e coating on one side & the installer had to get the supplier in to verify which side was which as there were no labels on some windows. The supplier had a reflectance meter that easily showed which side was most reflective, but reflecting both uv & infra red seems a serious technical challenge given that the wavelengths are so far apart.

Many transparent plastics are infra red opaque. I once built an infra red triggered goods display inside a plastic fronted display box. The idea was to light up the display only when there was someone in front of it, but it didn't work as the infra red from the potential buyer didn't pass through the plastic front & I had to move the infra red sensor to a direct line of sight with no interruptions. All of this worked well from a technical perspective, but In the by and by a thief smashed the box open & stole the goods!

Glass will also absorb enough infra red to make lighting paper with a magnifying lens near impossible, but the same lens outside on the same day would burn paper.

Another feature of many transparent plastics is that they wave length shift. One of these plastics will appear blue on the edges as the uv is wavelength shifted into visible blue light. We used this technique in a cosmic ray Cherenkov detector to shift the Cherenkov light to wavelengths that the photo multipliers could detect. On the maiden flight the detector came down on its parachutes from 120,000 ft, hit a ground power line, caused a fire & was destroyed. To add insult the parachute landed in a sewage lagoon.

Regards,

[mc2fool]

All fine and useful for those that live in hotter climates. How about a paint that detects the seasons and reflects heat in summer but absorbs it in winter?

[scotia]

Way back in the era when we thought Civil Defence was a good idea to protect us in a Nuclear War, the advice, in the event of war, was to whitewash the windows. This would reflect the initial flash from a bomb which would otherwise create fires in the home, although the windows would get blown out by the following blast. I received a nice letter telling me my services were no longer required when the Civil Defence was disbanded. It was generally accepted that we wouldn't survive a few H-Bombs, whitewash or not.