Researchers at Columbia Engineering have invented a high-performance exterior PDRC [passive daytime radiative cooling] polymer coating with nano-to-microscale air voids that acts as a spontaneous air cooler and can be fabricated, dyed, and applied like paint on rooftops, buildings, water tanks, vehicles, even spacecraft -- anything that can be painted. They used a solution-based phase-inversion technique that gives the polymer a porous foam-like structure. The air voids in the porous polymer scatter and reflect sunlight, due to the difference in the refractive index between the air voids and the surrounding polymer. The polymer turns white and thus avoids solar heating, while its intrinsic emittance causes it to efficiently lose heat to the sky.
Journal Reference:
J. Mandal, Y. Fu, A. Overvig, M. Jia, K. Sun, N. Shi, H. Zhou, X. Xiao, N. Yu, Y. Yang. Hierarchically porous polymer coatings for highly efficient passive daytime radiative cooling. Science, 2018; eaat9513 DOI: 10.1126/science.aat9513
The new desert home paint?
(Score: 5, Insightful) by Immerman on Friday September 28 2018, @03:15PM (9 children)
A "paint" that causes surfaces in direct sunlight to become cooler than the ambient air? Now that's impressive, especially if it has the potential to be produced cheaply.
The first question that springs to mind though is - how do you keep that micro-porous surface clean? Seems like it would be a huge dirt magnet, and any protective coating would need some pretty impressive properties itself to avoid crippling the radiative properties of the surface beneath it.
Perhaps the better question is, how long will it remain effective as grime accumulates on it? And can it be cleaned effectively?
(Score: 3, Interesting) by KilroySmith on Friday September 28 2018, @03:23PM (7 children)
I live in Phoenix, AZ, and would be remarkably interested.
A common building technique here is to use a flat roof with a white elastomeric coating on it for rainproofing. When you don't have to worry about snow loads, there's no real reason to build a pitched roof, donchaknow. Anyway, the roof is expected to be recoated about every 5 years - otherwise cracks and general weathering start to deteriorate the base layers leading to an expensive tear-up and replacement. A substance such as this that would last 5 years and then get renewed with a recoat would be fine. Heck, if it's as good as they say, having to recoat once a year would probably still put me ahead on A/C costs.
(Score: 3, Informative) by realDonaldTrump on Friday September 28 2018, @04:20PM (6 children)
Very easy and you don't have to wait for this one. You go to your hardware store. And you ask for the Solar Reflective Paint Additive. Trust me, you'll save BIG on your AC with that one. And it works with every color of paint -- even black!!!!
(Score: 0, Flamebait) by Anonymous Coward on Friday September 28 2018, @04:34PM (1 child)
I hope there's a special place in hell for you. There aren't any beachfront properties or golf courses where you're going, you sick bastard. What good will solar reflective paint do you in the eternal fires of damnation? How's that going to save you when they throw you in the lake of fire? I hope it's teeming with sharks, just for shitstains like you.
(Score: 2) by realDonaldTrump on Saturday September 29 2018, @04:57AM
That one's between me and God. And I think God likes me A LOT. He made me VERY SMART. Put me in a fantastic Family. In the best Country. And I've made a lot of very very smart decisions. But I've also had tremendous luck. God gave me a beautiful Brain and beautiful Luck. Like nobody else has. I thank Him for that. I'm always thanking Him. And I've done a lot for God -- more than anybody else has ever done. Especially since I went into politics. I picked Mike Pence, very strong God person. Religious. I moved my Embassy to Jerusalem -- fulfilling a Prophecy. Making the Bible come true. And I nominated Brett K., very devout Catholic, for SC. Very strong moves for God. If you were God you'd be very happy right now. And you could say, my agenda is God's agenda. Many people are saying that!!!
(Score: 2, Touché) by Anonymous Coward on Friday September 28 2018, @05:43PM (3 children)
So let me make a wild guess here. Bill Spaulding is a golfing pal and/or you own a bunch of RPM stock.
(Score: 2) by realDonaldTrump on Saturday September 29 2018, @03:18AM (2 children)
I didn't say Rust-Oleum. We love Rust-Oleum. But there are many brands. 3M, so many. We love ENVIRONMENTAL. And we've gotten many awards for environmental. More than anybody.
(Score: 0) by Anonymous Coward on Tuesday October 02 2018, @08:59AM (1 child)
(Score: 2) by realDonaldTrump on Tuesday October 02 2018, @09:42AM
Trust me, I've gotten TOO MANY to list. I'm known as America's Environmental Hero. Read Ed Russo's book!! amazon.com/Donald-J-Trump-Environmental-Hero/dp/1535456868 [amazon.com]
(Score: 3, Touché) by DannyB on Friday September 28 2018, @06:42PM
Take off your science hat. Put on your manager hat. That is a problem which occurs only AFTER we have their money.
The anti vax hysteria didn't stop, it just died down.
(Score: 3, Informative) by The Mighty Buzzard on Friday September 28 2018, @03:55PM (10 children)
I wonder which side the eco-folks will come down on for this. Pro because it leads to energy reduction or Con because it requires chemicals produced by companies they spend most of their time hating on?
My rights don't end where your fear begins.
(Score: 4, Interesting) by rondon on Friday September 28 2018, @04:03PM (5 children)
I'm probably pretty far on the eco side of your eco to (what is the other side, exactly? polluter?) whatever scale, and I think technologies like this are fantastic as long as they don't become some awful poison as they degrade. Which seems unlikely to be honest.
People can't maintain a decent quality of life in many of the places we live without air conditioning, and we aren't going to change society to live without it, so improving our methods is the only hope for reducing energy expenditure.
By the way, hating a company for polluting and respecting their accomplishments in other areas aren't mutually exclusive thoughts. It just seems that way in our currently polarized society.
(Score: 2) by The Mighty Buzzard on Friday September 28 2018, @08:03PM (2 children)
I'd be more concerned about how much polluting went into creating and applying them if I were you. I'm not a chemist, so it's not something I can speak with authority on but I would be interested in finding out the environmental cost start to finish. If it's greater than the cost of the additional power usage for the lifetime of the home, it makes the opposite of sense to use it. Also, if it uses fossil fuels during creation, that puts environmental activists in a pretty dicey ethical position.
My rights don't end where your fear begins.
(Score: 0) by Anonymous Coward on Saturday September 29 2018, @01:08PM (1 child)
When you abstract away the costs to society, people stop caring. They could use 10 times as much energy and cause a lot more environmental damage producing this stuff than running AC does, and people wouldn't care, because they don't see that. They feel good about "being green".
(Score: 2) by The Mighty Buzzard on Saturday September 29 2018, @01:47PM
Idiots are gonna idiot; nothing you can do about that. The primary goal here is to make sure I'm not in their ranks. The secondary is to get as many others as possible to engage their brains before they form opinions.
My rights don't end where your fear begins.
(Score: 2) by Pav on Friday September 28 2018, @11:21PM (1 child)
It gets a "3" on the German WGK (water hazard class) scale... ie. the highest - severe.
(Score: 2) by Pav on Friday September 28 2018, @11:23PM
Ref: https://www.chemicalbook.com/ChemicalProductProperty_EN_CB5756823.htm [chemicalbook.com]
(Score: 2) by Thexalon on Friday September 28 2018, @04:46PM (3 children)
As someone who's definitely among the eco-folks, you'll have to do the math to demonstrate that not only does this work, but that it's better from a keep-the-carbon-in-the-ground standpoint than alternatives like:
- Painting rooftops white, or installing "green" plant-based rooftops.
- Existing standard building insulation.
- Proper caulking around doors and windows.
- Replacing older single-paned glass, or putting a storm window or something else to improve insulation of windows.
- Replacing A/C units with cheaper-to-run heat pumps.
And yes, I'm putting my time and money where my mouth is: I've been spending much of my last week in my attic replacing old rotting compressed maybe-R-10 insulation with modern R-38, which is the current standard for my region.
Part of the shift is going to have to be realizing that buildings in warmer climates are now generally expected to maintain a temperature difference with the outside during the summer, which means building them more like buildings in colder climates when it comes to insulation. That's not the standard right now. Also, I think it's perfectly reasonable to question whether Phoenix, Houston, and other cities in the southwest are larger than they should be, and perhaps we should be thinking about getting people moving northwards with tax incentives or something as climate change makes southern cities less hospitable.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 2) by The Mighty Buzzard on Friday September 28 2018, @08:09PM
I don't particularly care from an eco standpoint. There's no need to consider it. I'm going to care about anything that reduces my bills anyway and this sounds like it would.
Nice. Very Stalin-junior of you. How about next we regulate how many kids they're allowed to have and how far they're allowed to live from their job? Both have significant climate impacts.
My rights don't end where your fear begins.
(Score: 3, Interesting) by EETech1 on Saturday September 29 2018, @04:30AM (1 child)
I have black plastic mats that are about 4 foot by 8 foot on my roof made from small parallel tubes that circulate the water from my pool through them.
Example: http://www.heliocol.com/ [heliocol.com]
The South half of my house has them, the North side has trees, and greyish shingles.
Besides running a 5000 BTU window A/C to dehumidify the bedrooms a few nights a year, the reduced heating of the roof makes the house very comfortable in summer.
I would think something very similar could be done with geothermal as well.
Run it through the house, then through the roof.
(Score: 2) by The Mighty Buzzard on Saturday September 29 2018, @01:55PM
Just get a properly installed metal roof. They lay down a heat-reflective barrier underneath the metal then physics takes over and draws cooler air from the bottom of the roof up and out the top as the metal heats the air underneath it.
Save the water cooling for the outside coil of your heat pump. Lay water pipe all throughout your yard deep enough for a constant temperature, attach a little pump and a small reservoir, and use it as a heatsink to heat or cool the outside coils as appropriate. My old heating and air boss had that sort of setup at his house and paid a little bit of nothing to keep his place pleasant year round because of the massive difference in heat transfer efficiency.
My rights don't end where your fear begins.
(Score: 3, Interesting) by Tara Li on Friday September 28 2018, @04:07PM (4 children)
http://www.sciencemag.org/news/2017/02/cheap-plastic-film-cools-whatever-it-touches-10-c [sciencemag.org]
This could be nice. Wonder if it could be used to generate water in arid areas.
(Score: 2) by bob_super on Friday September 28 2018, @04:19PM (3 children)
It really feels like a dupe, but I can't find the original.
(Score: 2) by bob_super on Friday September 28 2018, @04:22PM (2 children)
Eerily similar concept, but described as a different technique:
https://soylentnews.org/article.pl?sid=17%2F02%2F13%2F1634238&from=rss [soylentnews.org]
(Score: 2) by realDonaldTrump on Friday September 28 2018, @09:34PM (1 child)
The title is the same. And, they put the Link. Which is the same.
(Score: 3, Funny) by Ethanol-fueled on Friday September 28 2018, @11:19PM
Probably Deja Vu from hearing it so many times on Star Trek.
(Score: 1) by nitehawk214 on Friday September 28 2018, @05:31PM
If it doesn't last more than one season in an area that gets weather, it isn't going to be any more cost effective than air conditioning.
It reminds me of the convention center here. They planted one of those roof gardens to help keep temperatures down. Unfortunately the garden causes a leak that ruined the roof in that section costing a lot more to repair than they would save on the cooling costs.
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 2, Informative) by Anonymous Coward on Friday September 28 2018, @05:52PM (2 children)
I lived in the Arizona desert for close to two decades. As a teenager a door-to-door sales guy sold us a polymer insulated roof coating for our mobile home as well as a microfiber sunscreen for our windows. It did indeed help keep things cooler indoors. So I'm having a hard time understanding what is truly novel here.
(Score: 2) by bob_super on Friday September 28 2018, @06:57PM (1 child)
Read again: This (and the previous one I linked) not only reflect most incoming light, they also radiate heat in the infrared faster than you'd expect. In the end, the small incoming heat is less than the outgoing heat, so the result is a coated object which stays at ambient despite being in the sun.
(Score: 0) by Anonymous Coward on Saturday September 29 2018, @05:03AM
It actually cools by 6 C from ambient.
(Score: 0) by Anonymous Coward on Saturday September 29 2018, @03:31PM
"Grenfell Tower underwent a major renovation, announced in 2012 and conducted over 2015-16. The tower received new windows, a water-based heating system for individual flats and new aluminium composite rainscreen cladding. The purpose of the cladding was to improve heating and energy efficiency, and external appearance.
Two types of cladding were used: Arconic's Reynobond PE, which consists of two, coil-coated, aluminium sheets that are fusion bonded to both sides of a polyethylene core; and Reynolux aluminium sheets. Beneath these, and fixed to the outside of the walls of the flats, was Celotex RS5000 PIR thermal insulation."
Mmm toasty.