Comments
Onequestion0110 t1_iv6qs9k wrote
Also the cost to apply it, how durable it is, etc.
I could easily see a coating that works great but turns to tinting after a couple of years and is impossible to remove.
Or it takes specialized training and equipment to apply like repainting a car does, so even if the raw material is cheap it becomes a big expense and hassle to do it.
Twirrim t1_iv7ogva wrote
The church I went to growing up had beautiful Victorian stained glass windows, by a particularly important artist.
In the 70s the church was strongly advised to put some specific coating on the outside to protect and preserve them for future generations. It was transparent, and durable.
Within 10-15 years it was this beige translucent colour and only got worse with time. The church almost looked boarded up by the late 90s, while it still looked beautiful on the inside.
Of course a method didn't exist (at the time) to actually remove it, either, without damaging the frame.
Bman10119 t1_iv7f753 wrote
How does it affect homes in places that have changing seasonal temperatures? Sure making all the homes in Florida cooler isn't bad but if the savings are going to be lost by a house further north because it still made it colder in the winter driving up heating costs then is it worth it?
RedditTab t1_iv7jz39 wrote
Bold of you to assume we see the sun in the winter.
Bman10119 t1_iv7mlfd wrote
I've lived in plenty of places with snow and cold winters that saw the sun in the winter :p
ilep t1_iv80u2w wrote
Further north you go, longer the period when sun doesn't rise above the horizon. Arctic circle marks the latitude when sun doesn't rise at certain time of the year.
Just saying. So this kind of coating would not make difference as heating from direct sunlight would be small in any case.
But I would assume there would be different products for different regions like they are these days.
JasonDJ t1_iv7sx1p wrote
Yeah…I’m in the sweet spot this time of year where the sun blasting through my glass storm door provides more heat than I lose from drafts.
Gotta love southern-facings.
RandomLogicThough t1_iv7tkj9 wrote
I would think colder really just means more insulated which is better for heating or cooling
aldhibain t1_iv8ixnw wrote
The article states that they're trying to cool the building by radiating heat in addition to reducing the heat that is coming in.
RandomLogicThough t1_iv8j4px wrote
I feel that would also stop heat from getting out. I'll look at the article...sometime....
epochellipse t1_iv8n8hn wrote
oh see then you just turn the window around.
supercrossed t1_iv7qfwj wrote
Wonder if it could be sandwiched between two panes of glass to help with durability. That way the coating has no exposure to the elements.
snackelmypackel t1_iv7y4is wrote
Kinda like a windshield? Except i think those are plastic or something sandwiching the middle glass
Arrowcreek t1_iv81zy3 wrote
Uv blocking poly. Mostly for structural integrity. Uv and what not is just a bonus.
Contundo t1_iv84zqc wrote
Normal glass is 2 or 3 layers often filled argon gas between them. put This on the outside of the middle layer, its protected from the harsh environment and could be in a mostly inert atmosphere.
_Rand_ t1_iv8elty wrote
Hopefully it doesn’t break down just due to UV.
Would suck to have yellowed completely unrepairable windows.
Zech08 t1_iv8crrn wrote
They have double paned windows, guessing the air acts as an insulator, dont see why we couldn't add a material inbetween that.
FidelCashdrawer t1_iv8f7op wrote
Indeed window companies do this. They’re called “Low E” (Low emissivity) coatings and do a great job
sirkilgoretrout t1_iv77zvh wrote
Its in the second paragraph, first sentence. Common materials in layers. Silicon dioxide, silicon nitride, aluminum oxide, titanium dioxide, all on top of standard glass, with a topper of PDMS.
I’m pretty confused, as PDMS is a flexible plastic and kind of jelly-like. It doesn’t seem like something with a PDMS top layer would even be close to durable.
cope413 t1_iv7fmq7 wrote
Pdms has been used to coat solar panels for a while now. It increases the efficiency.
Wouldn't be ideal for windows on the first floor of a house, but on a skyscraper or multi-storey building, it would be durable enough.
sirkilgoretrout t1_iv89p9m wrote
Interesting… is that due to reduced absorption in the near-UV range vs acrylic, polycarb, etc?
cope413 t1_iv8aitb wrote
Yes, it has exceptional intrinsic thermal and UV stability (won't suffer degradation), and it has excellent transmittance.
It's also used as a boundary to prevent lead oxides from forming (called PDMS passivating). This is the main way that PDMS increases efficiency of solar cells.
SignorJC t1_iv8h50d wrote
Yeah but we could also have just required those skyscrapers not be built with so much glass in the first place. Horribly inefficient but we did it for the aesthetics.
derpymcdooda t1_iv7oq28 wrote
Part of the issue with glass coating is the carriers that get used during production. Dimethyl Tin and Hydrofluoric acid are both extremely toxic and very common carriers. At least for Vapor Deposition Coating.
Source: work in an online coated float glass facility.
A bigger question is, imo, how finicky is that stack going to be to actually apply
sirkilgoretrout t1_iv89gxn wrote
You mean like a post-market film install on current glass?
I’m definitely familiar with HF, but what the heck is dimethyl tin??
derpymcdooda t1_iv89whw wrote
The coating stack. In online applications it's deposited while the glass is still hot, before annealing.
Dimethyltin Dichloride. Pretty nasty stuff, really.
YobaiYamete t1_iv7rsn3 wrote
> Its in the second paragraph, first sentence.
You expect us to do more than read the headline??? Mods, ban this heretic
sirkilgoretrout t1_iv88oxd wrote
You obviously read the comments, and the Mod’s submission statement has it too.
But I do appreciate your 3rd grade level attention span and commitment to the reddit ways. You’re part of what makes this place special 😀
YobaiYamete t1_iv8bspm wrote
. . . the fact that you missed such an extremely obvious joke, while managing to be insulting about it, is pretty impressive tbh
sirkilgoretrout t1_iv8c9gc wrote
Just call me Karen
nanoH2O t1_iv83shx wrote
You can vary the cure ratio of pdms etc to get different flexibility. You can make a pdms film that is acrylic like.
sirkilgoretrout t1_iv89382 wrote
Mind blown. When I was doing microfluidic devices with PDMS, I always ended up with surfaces that would collect dust and lint like a little kid’s squishy toy. They’d be great on day 1, but we usually re-made samples regularly. Our lab shifted to deep SU-8 molding in part to avoid some of these surface issues.
BluudLust t1_iv77beg wrote
Simple solution to toxicity could be to have double layer glass and have this coating in the middle. If it really saves that much power, it will be well worth it.
-ThunderGunExpress t1_iv772ej wrote
They've had this for awhile. It's called ceramic tint
Resonosity t1_iv7u5ja wrote
Exactly
Have to always remember the toxicology of these materials, for humans and other biology, as well as what decommission/demolition/disposal/recycling of these technologies would be
Green/circular/sustainable chemistry is just one facet of getting at this
talligan t1_iv82ix2 wrote
They didn't make it, it was a simulation study.
penguinuendo t1_iv7gtjy wrote
>silicon dioxide, silicon nitride, aluminum oxide or titanium dioxide on a glass base, topped with a film of polydimethylsiloxane.
Waiting4RivianR1S t1_iv7zmk6 wrote
Buzzkill. You won't live to 50.
bigdish101 t1_iv79uxf wrote
Hasn't UV+IR blocking window tint been around for decades?
dalwen t1_iv7p1hv wrote
Yes, low-e coating. Designed to selectively transmit light in the visible spectrum but block/reflect IR and UV.
sunybunny420 t1_iv97455 wrote
Yeah this is confusing AF to me I’ve literally have some of this in my Amazon cart for like 2 years
It seems difficult to put on its essentially window tint. It’s shatter-resistant so it helps with flying objects and can make it more difficult for a break-in, and it deflects outside sounds. It’s cheap AF and comes in aqua, green, pink, amber, yellow, blue, black, and “silver” which gives an HD effect to the stuff outside. It’s easy on the eyes, and doesn’t look darker inside, the light’s just not harsh at all.
Reduces indoor temp by up to 12° Plenty of Amazon reviewers have test vids.
Should prob go through with that purchase soon it’s only like $16 but it seems difficult to adhere to the window. It’s v thin and you use soapy water and a credit card to squeege out the bubbles. People say it takes hours to do, so I’ve been procrastinating.
I guess these researchers didn’t try Google Shopping first lol
professorstrunk t1_iva0ghn wrote
Buy an extra wide squeegee and it’s a whole lot easier. Just keep wetting the surface of the film so the squeegee slides smoothly (Windex works fine).
Mr_Lucasifer t1_iva333d wrote
I think the difference is that the computer suggested using nanoparticles that are just above the short range of violet light, so blocking out UV light, and... I guess it figured out the correct range for IR. I'm confused about that part myself. Because IR is longer than red, and UV is shorter than violet.
In other words, if you layered a thickness of nano particles on glass in the exact range you wanted to block, visible light would still come through, but not the offending light you want to get rid of. A bit more sophisticated that tinting I think.
Scullvine t1_iv87j6v wrote
Yep, it's referred to as "curtains" when I use it though.
FearLeadsToAnger t1_iv8g818 wrote
Curtains are in the house, and are getting hot. You would need to hang curtains outside.
Scullvine t1_iv8qj93 wrote
They are, but due to scattering and refracting in a normal, unprotected room, less surface area is exposed that could absorb the heat. So curtains cool rooms pretty well. If you want to increase that, you could make reflective curtains I guess. But your neighbors wouldn't be happy, and it'd look weird.
fml87 t1_iv8udpl wrote
That doesn’t really make sense. Once the light has entered the space the energy is there. It doesn’t matter if that energy is spread over a large surface area or small, it’s the same total energy.
Curtains do make a difference because they do reflect light back out of the window even if they aren’t mirror-like.
HKei t1_iv9c0dh wrote
They also absorb and re-emit heat, some of which will go into the room, though some will go right back outside too.
DogsSureAreSwell t1_iva0al9 wrote
It matters if some of the delivered energy goes right back out the window.
Inside the room, heat the floor and you'll have convection and such pushing heat everywhere.
Inside a hot curtain even if it had 0 insulation value, half (ish) of the heat is going to head towards the room, and half (ish) is going to head back towards the window. The hotter the pocket between the window and the curtain, the more is going to head towards the room, the better the curtain is insulated, the more is trapped against the window to be transmitted back outside.
fml87 t1_ivak9lj wrote
In theory maybe but not in practice. The vast majority of the heat will be carried into the room via convective current. You’re also not going to get 50% heat transfer back out of an insulated window vs a sheet of fabric.
ConsultantFrog t1_iv9ynar wrote
You mean shutters?
FearLeadsToAnger t1_iv9zc2k wrote
Do I mean shutters? No.
Would shutters fair better outside than curtains? yes.
nool_ t1_iv8zsxe wrote
Yes bit are they transparent
steve626 t1_iv7xvje wrote
It's a layer of silver nano particles.
HardCounter t1_iv8p1ey wrote
Also, i'm no scientists but i've heard thermodynamics can't just be ignored. How is the temperature going down? All of the heat generating energy can't possibly be reflecting as well as taking some internal heat with it. Wouldn't a warmer temperature outside naturally lead to a warmer temperature inside given enough time?
EmperorArthur t1_iv8rfne wrote
What it's doing is stopping IR from going through the window and heating the room. The outside of the window instead absorbs it all and gets hot.
The reason that doesn't transfer all inside is first because can dissipate part of the heat on the outside surface. Second, the glass on the outside is separated from the glass on the inside. Which provides insulation.
Scullvine t1_iv8s45d wrote
Here's direct quote from the original published paper that acknowledged that and kinda makes it seem like the authors of OP's article hammed it up a bit:
"The device is tested in Phoenix for 37 h, and the chamber with the TRC can have a temperature up to 6.1 °C lower than that with the glass slide (Figure 4B and Figure S7). We note that both chambers have temperatures higher than ambient temperature because the transparency in the visible wavelength range of the TRC allows solar heating. In practice, TRC can work with other existing (e.g., air conditioning) or emerging cooling technologies (e.g., subambient radiative cooler) to reduce the overall cooling energy consumption of buildings."
nool_ t1_iv8zubq wrote
It's not going down its simpley never getting therr in the first place
HKei t1_iv9bvgw wrote
> Wouldn't a warmer temperature outside naturally lead to a warmer temperature inside given enough time?
sort of? It's a question of how much is "enough" time. Good insulation can keep a noticeable temperature difference without active cooling or heating for a very long time. In addition, temperatures outside don't stay at peak forever. For instance, if temperatures outside can hit peaks of 50°C but temperatures inside never go over 30°C that's huge win even if you'd like it a bit cooler still. With clever engineering you can reach much more extreme temperature differences using only passive cooling and insulation, but not without making sacrifices to aesthetics and on other fronts.
Lord_Blackthorn t1_iv8efc9 wrote
Yep, VO2 and VOx is a current popular material for "smart window" research.
GWJYonder t1_iv8s69v wrote
Yeah, I have them on my windows (it's really nice, except my cats don't get warm sunspots anymore). So this "breakthrough" may save 31% of power compared to "conventional" windows, but what is their improvement over similarly treated windows? Could just be 1% for all we know.
Beta_Soyboy_Cuck t1_ivasvtj wrote
The article seems to indicate it can also radiate heat in a wavelength where it can exit the atmosphere so it isn’t trapped (short v long wavelength radiation iirc). I’m not sure if the standard current tech does that.
Daves_not_h3r3_man t1_iv6tc8f wrote
50 years later we discover these coatings are in the air and water in the bloodstream of most animals...
einarfridgeirs t1_iv7a96h wrote
Why is it that every single halfway positive post in this sub instantly attracts a dozen or more top replies where people dream of every single reason why it wont work or turn out to be somehow horrible?
Where did our wonder and enthusiasm for scientific problem solving go?
Is the "doomer" generation really that wedded to the idea the future must be miserable?
chupo99 t1_iv7docm wrote
Because most of these "successful" scientific results never see the light of day in actual products. They're just novel lab discoveries. Great that they're being done. But doesn't mean anything in terms of changing the future.
15pH t1_iv7qn5o wrote
Every new tech that will radically change the future starts as a "novel lab discovery." Sure, most of the discoveries don't lead to much, but that doesn't mean we should see the glass as entirely empty and shrug our shoulders at everything. It is healthy and useful to be excited by new science and new possibilities.
Also, I think it is important to separate the impact of discoveries in physical sciences vs medical science. Medical "discoveries" are often in controlled petri dishes, and turn out to not be effective in a whole human where many complex complex systems interfere. It is usually appropriate to be pessimistic toward these over-hyped in vitro medical "discoveries."
On the other hand, a physical discovery or product like this one is fully REAL. The hurdles to making it "useful" are usually manufacturing and cost, which are only limited by current technology. We can innovate such things into existence in ways we cannot do with medicine. Thus, I think it is appropriate to be excited by physical discoveries and have them inspire wonder and innovation.
iama_bad_person t1_iv7lzen wrote
99% of all posts in this sub
gawake t1_iv8jqdu wrote
Not every inch of progress will revolutionize our world. It’s your expectations you should re-evaluate.
Daves_not_h3r3_man t1_iv7agfe wrote
No, I'm almost 50. I've been around enough to understand a very simple phrase.
Unintended consequences.
It's really not that complicated
Daves_not_h3r3_man t1_iv7bc3f wrote
And more specifically, people seem to want a quick fix. We are talking about very complicated topics ones that affect far more than just humanity which, unfortunately most people seem unwilling to tackle.
To reiterate, there's more to life than people. Until we can have a more holistic view of what life actually is, all of these things are temporary Band-Aids.
15pH t1_iv7mp9c wrote
We must always consider new tech risks in the context of the benefits. How useful is this new technology vs how likely and severe are the risks? It is wise to be concerned about potential risks, but we cannot ignore the known benefits.
Also, we should not fear unintended consequences based on a decades-old perspective. Over the last 40 years especially, the world has shifted from mostly ignoring the environment to having national and international regulations and watchdogs to address unintended consequences and new pollutants.
Of course, the regulations and watchdogs are still mostly weak and we still must be watchful, but it is time to evolve our default assumption from "no one has considered the unintended consequences" to "experts are testing and considering the materials and processes used."
unassumingdink t1_iv8609o wrote
> ver the last 40 years especially, the world has shifted from mostly ignoring the environment to having national and international regulations and watchdogs
Who are all some version of powerless, intentionally underfunded, or only able to levy fines representing a fraction of the money made from reckless activity.
LeRawxWiz t1_iv80ofd wrote
Because we really can't address these issues in good faith until Capitalism is abolished. We've seen this shit for decades.
Capitalism is anti-scientific method and anti-human. We need radical change, not just well-wishes and bandaids when the solution requires surgery.
Popswizz t1_iv73fhr wrote
Honestly, we might be at a point short term (under 1000 years old) trade off from biological problems are necessary to offset the millions years old problem that is climate warming through fossil fuel consumption
ten-million t1_iv79489 wrote
You just made that up. Nice!
Daves_not_h3r3_man t1_iv79upa wrote
I did lol...maybe with science getting so good, we can make this discovery in 25...
ten-million t1_iv7geea wrote
Lol. America is going to shit. If you don’t know, make shit up! Lol
CSyoey t1_iv69pyt wrote
Interesting, I’d love to see this implemented. Although I’m curious, wouldnt it reflect those ultraviolet and near infrared rays and possibly cause more damage to people’s skin and eyes while outside in areas with buildings that have this film?
TheSiege82 t1_iv6k71p wrote
What is the best option right now for a homeowner to reduce heat load coming from light while still maintaining as much visible light as possible? I have some huge windows that even in a utah winter have to be opened because the addition gets so hot. I’m the summer there are trees that help but the heat is pretty immense. My 3ton mini split can barely keep up and it’s only 600sqft or so.
windows it doesn’t help that they are pella casement windows from the mid 70s.
Draconicien t1_iv6p52z wrote
You can get double silver low-e coated high performance glass. It’s what they use in modern buildings. It’s designed to give maximum light transmission with minimal heat transmission
TheSiege82 t1_iv6yv96 wrote
Can that be applied after install like in my case
Lanemarq t1_iv73c4v wrote
It’s possible to have just the glass replaced with double paned, argon filled, low-e glass without ripping out the entire window. That said it’s a heavy YMMV. Depends on your specific windows and finding a company that will do it. As a general contractor I’ve got a window company that will do it, although they prefer not to and a glass company that don’t mind it.
You may have to call a few places, the big guys won’t do it, they’ll insist you have to replace the whole thing. The smaller mom and pop, or new start up company will be more hungry and willing.
There’s significant liability concerns on their part as the glass isn’t guaranteed to come out clean and you’ll have to know that going into it.
Replacing just the glass is less invasive for you as the home owner, but it may not go back together perfect, so be warned. There’s a lot of factors to weigh out and someone over the Internet won’t be able to answer what would be best or possible for you.
Draconicien t1_iv737xx wrote
No it cannot
Kaeny t1_iv6uske wrote
You need curtains or smth lol
space_monster t1_iv6wrce wrote
curtains don't do much. the glass itself heats up and radiates the heat into the room. you need something on the outside of the glass to bounce IR off it.
deevonimon534 t1_iv6z84j wrote
Outside curtains?
OldRub1158 t1_iv70s9v wrote
That's called shutters
ToxicTaxiTaker t1_iv79pkt wrote
You have no idea how many people don't realize that shutters weren't always purely decorative. In my region actual hinged shutters are a thing of the past, replaced by lame cheap plastic accent pieces that just screw onto the wall.
A good set of shutters with appropriate hardware could mean the world of difference in how your house performs in hot weather. They tend to blow off in heavy storms, but a stronger hinge and latch is all it takes to prevent that. I grew up with a set on my bedroom window, and it was awesome for night shifts too!
Kittenize t1_iv7ib22 wrote
Blinds like this actually reduced the heat in my house by a substitutial amount. They're installed on the inside
CHICOLOGY Cellular Shades , Window Blinds Cordless , Blinds for Windows , Window Shades for Home , Window Coverings , Cellular Blinds , Door Blinds , Morning Mist, 46"W X 48"H https://a.co/d/aMu1Qyx
Although we basically never look outside now but at least our AC bill is a bit lower
steve626 t1_iv7y4yz wrote
The glass reflects IR energy both ways. The windows are bouncing the heat back inside of the building too. Which is helpful in winter
TheSiege82 t1_iv6z0ol wrote
I have shade on the inside. But heat obviously gets in. And while I could do it on the outside that would be a logistical nightmare and eliminate a lot of visible light
Kaeny t1_iv7p2v7 wrote
Do blackout curtains not work?
TheSiege82 t1_iv83lyv wrote
I mean it would, but it’s the main room of the house. The main socializing area. So it’s not preferred
Goyteamsix t1_iv7f13s wrote
I have reflective film on mine. It made a drastic difference. It works like a weak one way mirror.
motogucci t1_iv74eyq wrote
There are already window films that come in rolls. Some are tinted, like aftermarket car tint, and some are reflective. They can make a significant difference.
It's difficult to achieve perfection on older windows, because there's probably grit stuck on the glass like cement, that's nearly invisible but could still try and cause bubbles.
But there's probably tips all over the internet if you look. I've used sewing needles to put a teeny hole that the trapped air can escape through when the film is squeegeed, with decent effect.
And overall, you'll have a much more pleasant, even temperature across the room. And the bills go down. Overall I think it's worth it, even though perfection was out of (my) reach.
CODEX_LVL5 t1_iv8p5sp wrote
Careful, these can wreck double paned windows. They increase heat beyond normal thresholds because the reflective coating is supposed to be on the exterior window, not the interior one
OkCarrot89 t1_iv7iqql wrote
Go on Amazon and buy some window film like the kind they're talking about in the article. That or buy some white thermal curtains to reflect the light away.
This is a very established and old issue that people have already made solutions to.
SuperElitist t1_iv7aca8 wrote
I think this is a concern with regular glass already, but not nearly as much of a concern as reducing energy costs.
John-D-Clay t1_iv7f7mk wrote
At most it would be equivalent to a mirror, doubling the sunlight. Assuming there aren't any stupid lensing shapes in the building like that one in London.
15pH t1_iv7scos wrote
The article implies NO, these wavelengths are ABSORBED in the coating, not reflected. The energy is then radiated back out at other wavelengths that penetrate our atmosphere.
Article is not clear, but that is my interpretation. In any case, I highly doubt it would be any worse than existing UV-blocking glass.
mossadnik OP t1_iv61thz wrote
Submission Statement:
>Studies have estimated that cooling accounts for about 15% of global energy consumption. That demand could be lowered with a window coating that could block the sun’s ultraviolet and near-infrared light — the parts of the solar spectrum that typically pass through glass to heat an enclosed room. Energy use could be reduced even further if the coating radiates heat from the window’s surface at a wavelength that passes through the atmosphere into outer space. However, it’s difficult to design materials that can meet these criteria simultaneously and can also transmit visible light, meaning they don’t interfere with the view. Eungkyu Lee, Tengfei Luo and colleagues set out to design a “transparent radiative cooler” (TRC) that could do just that.
>The team constructed computer models of TRCs consisting of alternating thin layers of common materials like silicon dioxide, silicon nitride, aluminum oxide or titanium dioxide on a glass base, topped with a film of polydimethylsiloxane. They optimized the type, order and combination of layers using an iterative approach guided by machine learning and quantum computing, which stores data using subatomic particles. This computing method carries out optimization faster and better than conventional computers because it can efficiently test all possible combinations in a fraction of a second. This produced a coating design that, when fabricated, beat the performance of conventionally designed TRCs in addition to one of the best commercial heat-reduction glasses on the market.
>In hot, dry cities, the researchers say, the optimized TRC could potentially reduce cooling energy consumption by 31% compared with conventional windows. They note their findings could be applied to other applications, since TRCs could also be used on car and truck windows. In addition, the group’s quantum computing-enabled optimization technique could be used to design other types of composite materials.
geroldf t1_iv84lzo wrote
Designed using quantum computing? That would be huge.
Arghhhhhhhhhhhhhhhh t1_iv8i307 wrote
Would be indeed. Except that's BS.
geroldf t1_iv98ey6 wrote
Why do you say that?
Arghhhhhhhhhhhhhhhh t1_ivc2be8 wrote
Anyone with any basic understanding of what quantum computer is will say that. So, get some basic understanding and you will know.
mutatedpeace t1_iv79veh wrote
There's already something like that, it's called the solar film.
Mr_krispi t1_iv6ud5b wrote
My cars windshield has a clear tint that helps reduce heat. This has been out for some time.
CA_TWINKIE t1_iv6z9ln wrote
Yeah, I thought ceramic window tints. Maybe this is better
justlikemymetal t1_iv7gxc4 wrote
This is actually a bit different but is using the same basic idea as radiant sky cooling. I think the company that already sells this is called sky cooling. Different application but same concept. Let through ir radiation.
ageispolispura t1_iv69dtt wrote
Really interesting. Wouldn't it make outdoor temps higher? Does it really reflect infrared heat and UV rays to space?
Mobius_Peverell t1_iv6d4l5 wrote
The volume inside of buildings is so dwarfed by the volume outside that it really wouldn't make much of a difference unless you're right beside it. Much like air conditioning.
soks86 t1_iv6dl4j wrote
That and reflecting heat truly does not in any way add to the total heat in the system.
Air conditioning is an expenditure of energy, electrical, which does generate more heat in the system.
Another way to think about it. Running air conditioners is consuming ~15% of global energy. This window idea would save ~5% of that. Adding more air conditioners would increase the ~15%, not decrease it.
Mobius_Peverell t1_iv6dsom wrote
Very true. Though it may redistribute it somewhat. Slightly more down onto surfaces within the window's reflection, and less on the tops of buildings where a/c units generally are. Though again, all very minimal changes.
soks86 t1_iv6o3d1 wrote
Well that might reduce comfort at the street level in dense downtown areas. Huh... although larger buildings actually take cold and pass it down (no compressed gas pipes going the length of skyscrapers as leaks would be hell to fix and probably dangerous overall) that doesn't change the effect of letting the heat off of the windows build up between buildings while the insides of the buildings bring less cool air to the base.
Electric cars to the rescue!
chupo99 t1_iv7epmu wrote
In laymen terms: We already use AC(which requires energy and creates additional heat) to pump the heat back outside anyway so it's more efficient to have a glass that doesn't let the heat in to begin with.
kagamiseki t1_iv8qx0t wrote
Explained another way: the same amount of heat that goes into the house, will come out of the house eventually.
Only question is how much extra heat do we generate by running out AC units to pump the heat out?
runswithcoyotes t1_iv6d9r7 wrote
> Wouldn't it make outdoor temps higher?
That’s how A/Cs work today.. except they consume electricity and produce additional mechanical heat.
Think of this as a way to passively create a cooler bubble within a hot climate by creating two areas of distinct average temperature. It’s not really adding anything to that climate, and the overall average is still the same.
dryguy t1_iv6dlmx wrote
| Wouldn't it make outdoor temps higher?
To the degree that there would be less heating of indoor air, there might be a bit more heating of outdoor air near the window from the UV and IR the window reflects, but the volume of outside air is so tremendously very much larger than the air in a room, it would be very hard to notice. The amount of heat dumped outdoors by an air conditioning unit would be a lot higher in comparison.
To the extent that it reduces the use of air conditioning, it would result in less energy consumption, hence less greenhouse gas emission. So you could argue that it helps keep outdoor temps lower.
ageispolispura t1_iv6efhw wrote
Thanks for the reply! appreciate it :) I understand the enthalpy exchange for AC units but wasn't sure if this was actually reflecting 'back to space' like it claimed or just reflecting it back outdoors. Even if it does just reflect back outdoors, what you explained makes a lot of sense.
ten-million t1_iv7bysi wrote
Are you kidding? All the low-e glass in windows now has multi layered coatings. They are code required now. Every new window has coatings. I spec out cardinal 366 low-e glass all the time. All the window manufacturers use just a few glass suppliers.
And these coatings save money and save energy. That’s why they use them.
octalanax t1_iv7997m wrote
What if it makes the whole universe hotter? What then?
What if we are heating up alien planets and causing global warming for them too? Oh noes!
BoujeeHoosier t1_iv85q4s wrote
No. Air conditioners pull that heat out anyway. In this case you wouldn’t be also using the fuels adding to the problem.
Nobubbles-notroubles t1_iv7lbu7 wrote
So it's just solar film? That's been around for a while
derpymcdooda t1_iv7ph4a wrote
It sounds like they take the same idea but are applying it to a Vapor Deposited Coating. So it should be more durable and you don't have to build a window and then apply the coating. It's in the glass surface.
Comprehensive_Leek95 t1_iv72dmh wrote
But it also means the reverse. Heat lost during winter
sauprankul t1_iv75rl4 wrote
Heating is way more efficient than cooling, so on average, this is still better. And the thermal energy lost through glass at night is significant. You lose heat from the building via radiation. If this coating keeps heat out, it'll keep heat in too.
EDIT: see comment thread below. Cooling might be more efficient than heating, so it actually would be better to let as much heat in as possible during the day during winter.
Lknate t1_iv7eh9k wrote
I live in Florida and absolutely use this principle. Once I have to start having to run heat, I start cooking a bunch. I'm talking about baking bread, roasting pork butts, large stock pots of gumbo and running my antique tube radio all the time. During the summer I actually run the toaster oven and air fryer outside because they are so expensive to pay to heat and cool at the same time.
winkapp t1_iv81a0z wrote
>Heating is way more efficient than cooling,
While the rest of your reply makes sense, this is just completely wrong. Cooling is way more efficient than heating, by a difference of 3.5x.
sauprankul t1_iv82ouo wrote
That's not what the abstract says at all. It says that places that get really cold like Minneapolis spend more energy than places like Miami, where it's livable year-round. That's where the 3.5x number comes from. I'll read the paper later when I have time, but I'm still standing by what I said.
"This finding suggests that, in the US, living in cold climates is more energy demanding than living in hot climates."
I'm open to evidence that shows I'm wrong. It'd have to be something like "it takes x% more energy to raise the temperature of a home by 1 degree than to reduce it by 1 degree".
winkapp t1_iv83e57 wrote
It literally says what you asked for.
> Another way of stating this is that it takes less energy to cool down an interior space by one degree than to heat it up by one degree. This is the case, because (in layman’s terms) it takes less energy to transfer heat (air conditioners) than to generate heat (furnaces and boilers).[…]
sauprankul t1_iv83j0t wrote
That's an extrapolation that whoever wrote the article made.
Paper: https://iopscience.iop.org/article/10.1088/1748-9326/8/1/014050
I didn't see it in the paper it cited. Show me a published paper that says that.
EDIT;
actually, you're probably right. It looks like those might be quotes from the paper. My bad
Staerebu t1_iv87egx wrote
The 3.5 times comparison is because it's comparing a heat pump (air conditioning) with heat generation (a regular heater, furnace etc.).
A heat pump transfering heat in would also be more efficient (depending on the outside temperature).
_Rand_ t1_iv8gmlc wrote
Also the fact that its a lot easier to be comfortable when its cold(ish) than when its hot will probably lead to lower heating costs.
Like, I can put on a sweater or throw a blanket over my lap and keep my house at 18-20c quite easily and not be uncomfortable, but when it its 35c out my AC can’t keep enough to get the inside temp below 25 or 26 and it’s absolutely miserable.
So while heating might be less efficient than cooling on a degree by degree basis, the need to heat/cool to specific levels may not at all be the same.
gladeyes t1_iv73cw3 wrote
Beat me to it.
bullitt4796 t1_iv73azv wrote
Umm, what different from this and coatings used in the industry for as long as I can remember?
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Covert24 t1_iv6dvfd wrote
Combine it with those windows that double as solar panels?
bomberesque1 t1_iv6ixiw wrote
these may be much more effective than the stuff my company used to install but this sounds like what we use to call Low-E coatings (15 years sonce I was in that industry though)
the principle back then (and i suppose today still) was/is to reflect all non visible light, ideally from the outer surface of the glass, so that the glass itself heats up as little as possible. This is tricky though as the coatings tend to be fragile so they tended to be applied to the inner surfaces of double glazed units (IGUs) to protect them. I was not on the marketing side so I don't recall how effective they apparently were.
Draconicien t1_iv6pfuh wrote
Correct. Applied facing the air/argon spacer in the double glazing unit. These low-e coatings are single silver, double silver, or even triple silver. Here in Dubai all out buildings use these. High performance glass is widely used.
frupp110 t1_iv79fyg wrote
Curious, does it make buildings effectively colder in the winter by blocking the sun’s heat from entering in?
Claytorpedo t1_iv7kxqa wrote
Sounds like it. It's likely intended for areas that are almost always hotter than desired inside. Maybe they can design panels you could put up for summer and take down for winter.
frupp110 t1_iv7uogs wrote
In the northeast US we often intentionally plant deciduous trees on the south side of our properties to block the sun with leaves in the summer and to allow the sun to enter in once winter comes and the leaves have fallen
saraphilipp t1_iv6hcfl wrote
Interesting. I've got ceramic tint on my front windshield that keeps the heat out. Why's this different?
CpnFluster t1_iv6uu11 wrote
That's cool!
But question is how hard it is to mass produce, how expensive it will be compared to energy saved, how easy it is to install, and the consequences for the cooler months inn the year most places have.
MrSurly t1_iv74csx wrote
Not to be that guy, but it would be "watt of power."
Silly-Bug-929 t1_iv7k6a7 wrote
There’s something similar already in the market. Ceramic window tint. Reduces glare, uv light, and overall heat transfer.
AmberHeardsGrodyTurd t1_iv7qqi0 wrote
Well that heat energy needs to go somewhere which means it'll reflect back into the environment creating even hotter heat islands around cities and shit
winkapp t1_iv81p2e wrote
The heat always needs to go back outside to create a comfortable living environment, now we use AC to do that which exacerbates the problem through the power used to run the AC.
The more AC you use, the hotter it gets and the more AC you use.
At least bouncing it back into the environment doesn't add heat.
AmberHeardsGrodyTurd t1_ivfbeip wrote
>At least bouncing it back into the environment doesn't add heat.
It does though. In fact it is such a huge problem that we literally design entire buildings around mitigating that part. You should look up "heat islands". Reflecting this heat back into the environment in an urban setting is not a great idea.
winkapp t1_ivhsxj0 wrote
Again, you're completely wrong. According to the EPA,
> "Urban heat islands" occur when cities replace natural land cover with dense concentrations of pavement, buildings, and other surfaces that absorb and retain heat.
> Trees, green roofs, and vegetation can help reduce urban heat island effects by shading building surfaces, deflecting radiation from the sun, and releasing moisture into the atmosphere.
Reflecting radiation improves the urban heat island effect, rather than making it worse.
Absorption of heat is what makes it worse, aka what we are doing right now.
AmberHeardsGrodyTurd t1_ivhu37t wrote
Bruh you need to read more
cobitos t1_iv8swrx wrote
Let me guess, it would cost 10k for a basic installation in a 1600sq ft house
FuturologyBot t1_iv66969 wrote
The following submission statement was provided by /u/mossadnik:
Submission Statement:
>Studies have estimated that cooling accounts for about 15% of global energy consumption. That demand could be lowered with a window coating that could block the sun’s ultraviolet and near-infrared light — the parts of the solar spectrum that typically pass through glass to heat an enclosed room. Energy use could be reduced even further if the coating radiates heat from the window’s surface at a wavelength that passes through the atmosphere into outer space. However, it’s difficult to design materials that can meet these criteria simultaneously and can also transmit visible light, meaning they don’t interfere with the view. Eungkyu Lee, Tengfei Luo and colleagues set out to design a “transparent radiative cooler” (TRC) that could do just that.
>The team constructed computer models of TRCs consisting of alternating thin layers of common materials like silicon dioxide, silicon nitride, aluminum oxide or titanium dioxide on a glass base, topped with a film of polydimethylsiloxane. They optimized the type, order and combination of layers using an iterative approach guided by machine learning and quantum computing, which stores data using subatomic particles. This computing method carries out optimization faster and better than conventional computers because it can efficiently test all possible combinations in a fraction of a second. This produced a coating design that, when fabricated, beat the performance of conventionally designed TRCs in addition to one of the best commercial heat-reduction glasses on the market.
>In hot, dry cities, the researchers say, the optimized TRC could potentially reduce cooling energy consumption by 31% compared with conventional windows. They note their findings could be applied to other applications, since TRCs could also be used on car and truck windows. In addition, the group’s quantum computing-enabled optimization technique could be used to design other types of composite materials.
Please reply to OP's comment here: https://old.reddit.com/r/Futurology/comments/ymyadn/researchers_designed_a_transparent_window_coating/iv61thz/
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azhawkeyeclassic t1_iv75tuw wrote
Be careful Pantone might try to charge you for that color!
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yeahimradd t1_iv77ir5 wrote
Would anyone be able to translate this into what this would look like for, say, average annual savings on an average US household?
JC_the_Builder t1_iv7bssl wrote
Don’t car windows already have a similar type of coating?
karma3000 t1_iv7ga05 wrote
How many units of energy are expended in the manufacturing process?
ursvamp83 t1_iv7j4ya wrote
Or you know, we could just not cover our buildings in glass...
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SandwhichEfficient t1_iv7qfxu wrote
Sounds like a polarized window tint with extra steps lol
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Objective_Spray_5015 t1_iv7uu01 wrote
Been around. Nothing new. Same ingredients different recipes.
ForceGhostVader t1_iv85r1h wrote
Yeah if you could just put this on my car that’d be great
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[deleted] t1_iv8c06x wrote
Been hearing about "photovoltaic windows" for a while now. When are we going to be able to buy them?
e-cigs-and-whiskey t1_iv8ebny wrote
I look forward to seeing this technology used never. Just like every other future tech posted here.
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Anok-Phos t1_iv8h5uy wrote
And also reduce fossil fuel use because fuck big oil.
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Nanteen666 t1_iv8ngzn wrote
I've always thought it's easier to build buildings without windows. Put cameras on the roof link them to thin LED screens that show the outside. I would have to think without Windows the heating and cooling of the building would be much more affordable.
Yes I understand that you'd have to change various building codes and fire codes, and help the public get over the idea that they're trapped. As if they were really going to be breaking a 110th floor window and jumping to safety
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gargoyle30 t1_iv9049t wrote
Just put movable solar panels over the windows, then you can generate electricity at the same time
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wooddoug t1_ivafe6r wrote
Great job using parameters that no one understands. Maybe use a percentage?
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skiddyiowa t1_ivgdegw wrote
My workplace did a renovation and added windows that tint themselves according to the amount of sun coming in. It’s definitely helped to regulate temperature within the office. Might not be the exact same thing but similar.
PreferenceHot8715 t1_iv71lqb wrote
Do everything except actually preventing climate change
thehourglasses t1_iv6hjy8 wrote
Curious what it is made of and how toxic it is. We need to be more cautious about these kinds of “breakthrough” materials because their manufacture at scale could cause worse problems like PFAS contamination, etc.