DIY Supermaterial Could Save You From Heatstroke: Salt based PCMs

[@Nighthawkinlight]

I have a hard time seeing all comment replies so if you're having trouble with something please leave a new comment, not a reply to this one. I've put some additional info and useful links in the video description. Do you have more ideas for how these PCMs could be used? I'd love to hear about it in a comment! I've been asked to provide measurements by weight for the 18°C PCM: 400g anhydrous Na2SO4, 80g NaCl, 1.2 L water, 15g xanthan gum or CMC. More water may be gradually added to the simmering mixture to dissolve excess salt, but do not add so much that all salt disappears. If you'd like to support these projects directly you can do so through Patreon: www.patreon.com/NightHawkProjects Thanks for watching! -Ben

[@isaacm1929]

Question: Is there a gas-to-liquid PCM?

[@Splarkszter]

Sometimes i think you should patent these if you can and then provide an Open License. So you still own it, but no megacorp and fuck you over :)

[@Nighthawkinlight]

@@isaacm1929 Yes, steam is one such gas to liquid pcm.

[@Nighthawkinlight]

@@Splarkszter There's a thing in patents called prior art. Basically once someone releases information publicly no one else is allowed to patent it. A video like this counts as prior art. That is, if there's anything in this video that's novel enough to patent anyway, which I'm not sure there is.

[@isaacm1929]

@@Nighthawkinlight Well, my fault. Without the high temperatures, or a gas to liquid in

[@DistortedSemance]

Ben is the only DIY youtuber out here doing projects that are accessible to average makers, but based on cutting edge research, with obvious practical application, and with a clearly documented process. He's not just a science communicator, he's a genuine innovator.

[@antoniojl16]

He is one. Are you sure he is the only one?

[@theflashturtle29]

@@antoniojl16probably not. If you have others in mind do tell!

[@antoniojl16]

@@Jonathan-vx7xi WOW. What a nice reference!

[@Jonathan-vx7xi]

another good one is @ThinkingandTinkering

[@sewi014]

A new scientific find kinda is just there at the start. (porducing fabric with tiny hooks and loops) Then someone finds a use but its still kinda impractical and needs a large setup to produce.(Velcro being used in Spaceflight) After that the process becomes more refined and more common until eventually it ends up in consumer hands (Velcro on sneakers). Ben just kinda skips that whole process, starts throwing stuff together in his garage, and somehow ends up with a replicaple, easy to follow process which is kinda amazing

[@thethoughtemporium]

This is absolutely amazing. I hadn't thought of how much cooling you could get from a thing that's stuck at 18 degrees.

[@Jimunu]

Oh a stray thoughtemporium. Your latest poster is super cool.

[@Nighthawkinlight]

Thanks! Good talking with you last weekend

[@kingmasterlord]

good, they know of one another

[@OSaracenU]

Time for a PCM upgrade to the Meatcubator?

[@SupremeRuleroftheWorld]

note that the efficiency is horrendus compared to direct cooling as needed. has a heatpump tech these things pushes all of the wrong buttons for me as the efficiency is just so bad and have no real world use for home/commerical heating/cooling.

[@rickarddt]

I'm a mechanical engineer, thermodynamics were one of my degree subjects. I specialise in refrigeration, testing, redesign, retesting and submitting to the regulator for approval, in a nutshell those stars you see on the appliance when you buy it, that's me. Usually people want to go from A to B, make things freeze at lower temps, the literature on this isn't accesable to the everyday reader, I've had a play with eutectics and lowered the freezing point, to where I want, in order to make those bricks you buy in the store. Who goes from B to A and raises the freezing point? Latent heat of phase change is brilliant. Man I'm enjoying this. Thank you for bringing this to the general public. Twice the latent heat of phase change? Brilliant work my friend.

[@Nighthawkinlight]

Thank you! I hope to see some fact checking of the numbers. I did the best I could with styrofoam cup caloriometers but I'd love to see some proper tests, and also reports of how people like the PCM packs in practical use.

[@Rockefeller.69]

Im currently job hunting. Went to school for Chemical Engineering. My favorite subject in school was thermo. I also have past experience with ISO standards and safety standards, so i like working in the world of regulations lol. What are some keywords that I should use in my job searches to find a job similar to the one you described?

[@rickarddt]

@@Nighthawkinlight I might just fire up the climate chamber in between optimizing product lines.. I appreciated your graph comparing the water and the modified mixture, (been staring at the latent water line for years, the modified mixture line is intriguing, behaves like a refrigerant mixture, where you mix to optimise).. On the solar panels (I'm no fan, energy density is a thing and understanding the difference is difficult and exploitable, nuclear is the way), however.. The load profile on solar batteries are variable, that's the first bit. For every degree (or two, can't remeber exactly) above design temperature those batteries are operated at, you halve the lifespan, this will counter that intermittent heat load and extend battery life in addition to the panels.

[@rickarddt]

@@Rockefeller.69 oof, I'd love to help, however I came across this job by word of mouth and implemented and aquired the testing facilities, equipment etc myself. My advice.. Do your current job as best you can, I don't mean be a mop or broom for your employer to use and get every last drop of out of you.. Do the job well.. While you are doing this continue to learn, read, read wide, you will find information that link, use that and try to implement through motivation (you will get rejected, if you hit a 20% success rate.. Celebrate! That's a brilliant motivation to implimetation ratio). Go where your skills lead you. Quantify your achievements..

[@RobertLBarnard]

It is brilliant! Is this similar to "power matching" (setting the phase change temp near the desired temp)? Power matching as in mechanical or electrical systems? I really enjoy learning about these materials. But beyond the physics, the cleverness of rightly solving problems, it's just fun! Thinking of how we sometimes want to overwhelm a problem, we instinctively want to over compensate, be "extreme". Maybe because we want to correct and keep something in reserve. But we really just want to "nudge" the temperature usually. The "reserve" exists in the continued energy absorption/release at the phase change temperature.

[@FuchsDanin]

You wanted to hear back regarding people who have made some -- we've made a dozen quarts or so of the 65F version. Hand towel packs in vacuum sealed bags for personal cooling. Slim drink bottles for freezer packs. It doesn't go below 85F here at night anymore, and for a while it was approaching 120F during the day, so I've been using four packs at a time, wrapped in a towel, under a covered couch on our patio to keep some recently-born feral kittens alive. We use them in a cooler in the SUV for groceries, since the A/C doesn't work. We just ordered a bucket of salt for the 85F version, as well. I'm interested in pairing it with the below-ambient radiant paint project to make shade panels for our house; we're pretty desperate to drop the power bill.

[@CharlesJoseph40]

Still watching the video to see how this works. I would make tubes placing them in an air duct with inline booster fans at the vents as an experiment to see how well it cooled. Say spaced two inches apart for two feet staggered so the air channels as it passes through.

[@OiculoveYah2]

@@CharlesJoseph40 I was thinking about mixing it in that way and use ground tube cooling. Should have to dig as deep.

[@jacobAnd8]

Could you create lined socks or gum boots for concreting to keep people cool and make money selling it to mining companies as safety for controlling internal core temperatures for heat stroke. I’d love to create it.

[@lisariggio6916]

What a smart idea!

[@lisariggio6916]

Get a patent on that paint ASAP

[@CollectiveSoftware]

This, fireproof paint, radiative cooling. Ben just looked at heat and said "Oh I think not. To the garage!"

[@criticalevent]

He's almost ready for unassisted reentry to the atmosphere!

[@Thing.Appreciator]

Yeah, imagine he puts them all together into some super cooling gizmo

[@rog2224]

Don't forget reverse engineering Starlight. That was what hooked me, since I saw the original Tomorrow's World demo when I was a child.

[@AflacMan13]

Hm. These materials, with a titanium hull for the fuselage... ... actually, I wonder if he is INDEED ready for atmospheric re-entry!? Could these materials be the key to a new kind of heatshield?

[@larrywiley1804]

Don't know if it was mentioned in the comments, but what abt warming a greenhouse in winter?

[@robstorms]

It is worth noting that in 1948 Maria Telkes built a solar heated house named Dover Sun House which used large tanks of sodium sulphate phase change material ( Glauber's Salts) to store daytime solar energy for night time heat. The heat storage tanks were of her own design, and she had been experimenting with Glauber's salts for many years.

[@dziban303]

so many folks in the comments seem to think he invented the whole concept. "This changes everything!" The credulity of these people is concerning. There is a reason this decades-old stuff isn't more widely used, and it's disappointing that so many people just haven't managed to put it together.

[@kimtae858]

@@dziban303 Care to inform us all of these deal-breaking issues since they've already been explored and itemized? Would save us all a lot of time repeating old mistakes that way.

[@SethCohn23]

​@@dziban303 if only people were writing papers on using this stuff in 2024... oh wait they are. No, he didn't invent it, he's making it well known, using homebrew cheap methods.this tech isn't obsolete or flawed, it's still being discovered and improved in 2024 by scientists, and garage inventors will invent new uses.

[@JanDahl]

In the back of my head, for years, there has been a nagging idea that something like that should exist for houses and indeed, something did! ❤️ She had the idea and followed through on research and building it. Awesome!

[@cupbowlspoonforkknif]

​@@dziban303The Wikipedia article says her system was removed after 2 years due to corrosion of the tanks and settling of the PCM. Both of these issues are solved now with our current technology. Plastic tanks, or maybe stainless steel and a gel agent as demonstrated in the video. So it may not be a new concept but revisiting an old one with new technology may work out to our advantage.

[@luke_fabis]

DIY radiative paint and now DIY PCMs. This channel is going solarpunk and I'm all for it.

[@JohnJeppson]

Between this and tech ingredients...

[@liquidrockaquatics3900]

Once the pole shift happens, we won’t need ice packs as much, but before? Definitely. And shielding from the sun. The earth’s magnetic field is at the weakest point in a very long time and we are past due for the magnetic excursion. South America and somewhere around China will be the new poles. Evidence from Antarctica shows that it has happened at least 9 times in the past

[@dchall8]

You forgot DIY Starlite from 2018.

[@Iliek]

Nothing has changed, except that the boys have new toys.

[@modernNeanderthal800]

Same

[@RobertMoser]

I've made several batches of these, and they work wonderfully. Been a big help during the heat waves we've been having here in California- one under each arm for about a ten minute heat break when working outdoors makes a huge difference! And they're 'warm' enough that you don't have to worry about overchilling the area of skin they're on. They definitely cool me faster than normal ice packs. A few notes: I've settled on using thermal vacuum-seal plastic as the holding method. Nice, strong plastic, and you can get all of the air bubbles out. CMC is not quite as durable as Xanthan Gum in the high salt environment as the sole gelling agent. I've tried CMC, Xanthan, Agar, Gelatin, and Corn Starch, along with various combinations thereof. The most resistant to crystallization has been a 50/50 mix of CMC and Xanthan. Agar has usually been my gelling agent of choice, but it doesn't seem to like the salt environment. Gelatin and Corn Starch were very weak. Don't mix the gelling agents in first, or it will be almost impossible to get the sodium sulfate to dissolve. (I did this version just out of curiosity, and, well, let my pain be a lesson. :D) Immersion blending as you add the gelling agents slowly makes for a much smoother pack. For the first freezing of the pack, use as cold a freezer as you have. It seems to set the structure better. After the first cycle, you can throw it in the fridge just fine. Do be aware that it will be a warm source for a long time in the fridge, so no easily spoilable foods nearby. Hope this helps some folks!

[@Nighthawkinlight]

Thanks for sharing your experience!

[@HigherEnlightment]

Great tips, thanks!

[@Metqa]

I've been trying to find out if table salt, with Iodine, would be a problem. I couldn't tell if I had to go get non-iodized salt because the Iodine might interfere.

[@RobertMoser]

@@Metqa Iodized or not won't make any difference at all. There's no need for it, but it doesn't hurt anything, either. Whatever table salt you have on hand will work just fine. 👍

[@42WallabyWaySydney]

Did you use a towel inside the vacuum-seal plastic?

[@DrumSmithRich]

As a firefighter and paramedic in Texas I wish we had something like this under our fire gear to keep us cooler during fire operations. Our gear is incredibly hot even outside of a fire and heat exhaustion is a regular occurrence for fire fighters all over the world. It’s like wearing a heavy winter jacket over a raincoat over another heavy jacket. Then do the same for pants throw on a ski mask, a 40 pound backpack, gloves and breathe through a straw. Now do that when it’s 100+ degrees and high humidity and do hard physical labor. We train to be able to do that for a time, the issue is when you can’t cool off because it’s so hot and humid outside.I could see these being used in rehab stations to recycle FF before going back into the fire building. We do use pcm packs to keep medications cool in apparatus without on board refrigerators.

[@BliffleSplick]

I admire you, your job is basically to be an extreme athlete for years

[@amandasaint8513]

I volunteer with my local VFD, we are going to make a few of these for rehab.

[@diggitydank420ity]

Some sort of fabric soaked with PCM backed with mylar to reflect heat away from the user. It might weigh a few lbs but the cooling may be enough to justify the weight. It could even be just a vest to be worn under outer layers

[@TheReaverOfDarkness]

I am a firefighter from the future and I'd think it was funny watching you guys struggle with the heat if it wasn't so sad

[@kd5nrh]

That's sort of what I'm thinking of using the plate carrier for: sometimes I need to be in a rainsuit in those super fun thunderstorms we get where it's pouring rain and still 90 degrees. Plate carriers are made to hold a big, reasonably thick plate, and keep it in place through heavy activity, so that should work for keeping a couple large bags of this stuff against my chest and back. At the moment I'm working with a small batch that doesn't have the xanthan gum in it yet, manually separating different freezing points by simply holding it around 40F for a while, then pouring off whatever isn't solidified, then letting it come up to 75F, keeping the liquid and removing whatever hasn't melted yet. Next I'll move the minifridge to a better spot and start dialing in a 68-70F melting point. Not sure why the too cold stuff and the too warm stuff don't want to mix and find a happy medium, but maybe there's something that will get them to play nice together.

[@argentpuck]

I accidentally have found myself working as a materials scientist despite lacking any related background. Stumbling across your channel, I have found my new hero. This is amazing stuff.

[@wtice4632]

How can i also stumble into this career?

[@krupert8355]

What do you work as?

[@argentpuck]

@@krupert8355 I run an R&D lab for a company that makes specialized ceramics for use in other industries. I started working on the factory floor and a series of random events resulted in my being put in charge of the lab. I have a literature degree and have had to do a lot of self-directed learning to keep up. On the other hand, I also had to explain to my boss, a Ph.D in physics, how electron valence shells work and how we use X-ray emission to verify atomic composition.

[@andreycham4797]

I do not know if he mentioned this but In the UK you can buy a heat storage tank with PCM. Last time I checked they were planning to start selling them in the US too

[@vampdan]

What a strange way to admit to starting your own meth lab. 😅

[@falcofranz5005]

There is a public building in Germany that uses PCMs for cooling. The cooling packs are located in the ceiling structure and are charged by the air conditioning system at night. They then cool the rooms during the day. The advantage is that the air conditioning system can be much smaller because the PCMs buffer the cooling demand. This solution is economically attractive in a region with a short heat period.

[@Nighthawkinlight]

That's a good idea!

[@srboromir452]

Plus less wear from stop/starts if you can just run the AC all night (when electricity is cheaper to boot)

[@Jehty_]

What's the name of this building?

[@NonEuclideanTacoCannon]

I love this. I've done a bit of HVAC work. I'm sitting here trying to imagine how to design a system around solid/liquid phase change, and the approach is completely different when your "refrigerant", for lack of a better word, solidifies. I was sort of imagining a two stage system, I was thinking too simply. I was thinking of a system with a hot side and a cold side, and I was imagining packs of PCM being physically swapped. Taking advantage of hot and cool periods (and cheaper electricity) is much more practical.

[@Videoswithsoarin]

tell california this

[@MrStreaty122]

Holy Christ… that cooling vest blew my mind. Most of the people I know work in the trades, apartment maintenance, manufacturing, etc. and I myself work in Security. I can see that vest actively preventing heat stroke and exhaustion for blue collar workers in my entire city… you, good sir, may have just given me an idea

[@Iliek]

Better think through that idea first. Don't rush to try and exploit people, like this man has.

[@Kosher3864]

​@@Iliekcan you elaborate?

[@cc-tb3st]

The vests are neat but when filled with ice they don't actually last long in high temperatures. I'm in Texas so 100f+ is regular in the summer. It was nice to have but heavy and didn't stay cold long. This stuff might extend the cooling affect.

[@jacobAnd8]

I want my cooling concrete boots already please sir

[@johnsmoak8237]

​@@Kosher3864by "this man" I think he meant himself

[@ChrisBloom]

as a beekeeper, I know that a lot of the energy my bees use during the day is spent on cooling during the summer and heating during the winter. I could see this being a great application for keeping the hives temperature regulated better and potentially increasing honey production and decreasing dead-outs on extremely cold winters.

[@fuocofuegofire]

The PCM works best if the temperature cycles across the crystallization temperature. In the winter, if the temperature stayed cold for days it will stay at the crystallization temperature and then drop when it's all crystallized. Then it will act like a regular thermal mass like a brick. Not much different than the honey in the hive. I think this might help though. The ideal brood temp is 92 degrees, so maybe using the calcium chloride would be better because it stays at 85f during the summer. The bees might not need to eat so much on the days when the PCM is recharged. For die off during the winter, a much lower temp PCM would be better because it would more likely cross the crystallization temperature. But the hive would also try to stay at that lower temperature on the sunny days. The outside temp of the ball of bees goes down to 47 degrees during the winter.

[@fuocofuegofire]

The 85 degree type would be good in a bat house for bats too, the babies like it hot in the summer. But not too hot.

[@garywheeler7039]

I was getting interested in beekeeping and my wife got a injector in case she got stung. She has many allergies. I was looking at PCM's at one time to keep the injector cool in a hot glove compartment. As another use for the technology, keeping life saving drugs cool.

[@BeyondPC]

Bee careful not to make bees dependent on climate controlled structures; it could have unknown consequences.

[@firstmkb]

I don’t hear the term Beekeeper the same way since I saw the movie titled The Beekeeper. Good work!

[@thetruthserum2816]

You are one of the few channels on KZbin that seems to be working on ideas and inventions that can improve the human experience and make people's lives better. You are a true asset to the community.

[@vidard9863]

Robert murray-smith is another channel you might like.

[@abowden556]

@@vidard9863 basically the only other guy who does this stuff lmao

[@vidard9863]

@@abowden556 yeah... I was kinda hoping that people would be chipping in other names that I didn't know about....

[@eruiluvatar236]

The progresive freezing below the freezing point of water makes sense. Some of the salt won't do the phase change and stay in solution, then as the water begins freezing, it does so with a lower concentration of salt than the remaining liquid and the freezing point of water depends on the disolved salts. It is used as an alternative to distillation called fractional freezing.

[@YoniBaruch-y3m]

What he said. Changing concentration during crystallization.

[@Ringadon]

I was thinking something along these lines too.

[@Makrond]

Also worth noting that - at least in my understanding - in an ideal eutectic mixture this wouldn't happen, the components of the system would change phase at an equal rate and you would see more distinct phase changes with longer periods of thermal arrest. How that would affect the cooling performance I'm not sure.

[@CRneu]

yup. you can do this aging alcohols outside in the winter. Store it in a barrel(like wine, bourbon, etc), as the temp drops the alcohol and other stuff with a sub 0c freezing point will stay liquid. People will pull off this liquid and sample it as a treat.

[@paradiselost9946]

@@CRneu sample as treat... do shots and get shit-faced, you mean?

[@DrPsychlops]

For anyone who forgets to drink their coffee until it’s cold, there is a company called burnout that makes mugs with a PCM between the vacuum layer and the liquid carrying portion of the cup. it keeps your coffee and drinking temp for hours. I'm not sponsored by them but I love them. They should sponsor Ben (:

[@Dysiode]

It's just incredible the amount of -practical- knowledge you basically just give away for free! I watch tons of KZbin that teaches me things I'll either never need or are too specialized for me to use. The fact you come along and go "here, add these three ingredients, soak a towel in them, and toss them in a vacuum bag" is surprisingly empowering!

[@veen88]

You have to cool that first before using it

[@YouTube_username.]

@@veen88yes that's because it's an ice pack and that's how an ice pack phucken works

[@MecchaKakkoi]

This is great! Recipe points in the video: 6:10 Recipe for 65f (18c) salt PCM 21:40 Recipe for 85f (29c) salt PCM

[@tbucknor]

From an American, thank you! We use imperial measurements here. Right now it's 95 degrees outside; I have no idea what that might be in metric!

[@SeanPAllen]

​​@@tbucknorHey fellow midwesterner (boy, is it hot out)! The formula for Fahrenheit to Celsius is (°F−32)÷1.8! So for 95° F, that's 35° C.

[@dinothunder5233]

Use google

[@K.W.W-Y]

​@@SeanPAllenI didn't get that calculation? Can u pls explain thanks

[@SeanPAllen]

@@K.W.W-Y (95°F − 32) × 5/9 = 35°C The freezing temperature of water at atmospheric pressure in F is equal to the freezing temperature of water at atmospheric pressure in C, plus 32, as the freezing point in F is 32°. This means you subtract 32 from temperatures written in F to get °C, before anything else. The next and final step is to take 5/9 and multiply the sum of the first calculation by it. Note that this is the same as dividing by 9/5, or 1.8. This is because every 1°C is equivalent to 1.8°F. Your end product should then be equal to the temperature in Celsius! If it isn't, you may want to check your work and I'm sorry I couldn't be of more assistance.

[@SirLordBabyPeen]

From 11:20, only pure elements and compounds freeze/melt at a consistent temperature, solutions vary. That cooling curve that you see is from the eutectic cooling curve that this solution follows. So essentially a small fraction of the liquid starts freezing/precipitating out hydrous Na2SO4 (and possibly hydrous NaCl) at 18C, where more of the solution will freeze/precipitate as it cools to -8C (eutectic point). At -8C, the remaining liquid freezes (at a consistent temperature) into 3 separate phases of ice, hydrous NaCl, and hydrous Na2SO4. When following these types of cooling paths, it is better to think in terms of liquidus and solidus, instead of freezing and melting. Liquidus meaning the temperature at which the solution will be 100% liquid, and solidus meaning the temperature at which the solution will be 100% solid. So with this solution in particular, the liquidus temp would be 18C, and the solidus temp is -8C. Also, the inclusion of the NaCl actually significantly reduced the gap between the nucleation temp (end of super-cooling) and melting temp compared to just Na2SO4. There is a study out there that used borax to increase the nucleation temp, I wonder if that would work with this solution as well. I would really like to see the heating cycle of this material at a slower heat rate to see the different regions of heating and how they compare to H2O, but the quick heating data is rather insightful, too. Like the PCM noticeably outperforming the water after 18C. I did not expect that big of a difference. Whether that is due to a difference in specific heat or thermal conductivity, I don't know, but it is pretty sweet to see. This was an incredible video with a ton of thought and effort put into it. I might try making some of this stuff with an old towel since my car's AC doesn't work. lol

[@cornonjacob]

I came to the comments to theorize roughly the same thing about the changing composition giving the decreasing freezing temperature, but you explained it much better. Also, I think it would make sense that poorer thermal conductivity of the PCM would make it seem to perform better than the water in some scenarios because he temperature probes were placed in the center of the samples, not outside of them where the heating work needs to be done.

[@Scapeonomics]

I'd bet that as the solution froze, the sodium chloride concentration of the remaining liquid increased, lowering the freezing point further.

[@TimNeumann]

I'm not an chemist, and I don't know how the water interacts with the salt in terms of thermodynamics, but there is one fact about his heat capacity measurement, that seems odd to me: Ben said, that his solution has twice the heat capacity of Ice. The solution consists 60% of water (by weight). His graph at 12:05 shows, that he cooled it down to around -18°C (same in the heating graph at 12:48). So any water should be frozen at some point, giving us 60% of the heat capacity of ice (enthalpy of fusion: 333.55 kJ/kg). Sodium sulfate (33.33% has an enthalpy of fusion of 254 kJ/kg). I think the NaCl (6.67%) does not effect the enthalpy of fusion, since the melting point is way higher. Doing some basic math: 0.6 x 334 kJ/kg = 200.4 kJ 0.3333 x 254 kJ/kg = 84.7 kJ Total: 285.3 kJ/kg enthalpy of fusion for the mixture. For the next part I assume, that the mixture consist of pure water (4192 J/kg*K), for worst case consideration, because I'm too lazy to do the numbers for specific heat capacity for both in liquid and solid form. The solution was warmed up from -18°C to 36°C, deltaT = 54 K, so 54 K * 4.192 kJ = 226.4 kJ The total Energy required to heat up the solution from -18°C to 36°C would be 511.7 kJ/kg, or 153.7% the enthalpy of fusion for ice in this worst case assumption. I guess it would be more around 110%-130% with the specific heat capacity for ice and Sodium sulfate. If I consider the direct comparison with Water/Ice, the the total Energy required would be 18K*2,06 kJ/kg*k (ice) + 36K * 4.192 kJ/kg*k (water) + enthalpy of fusion 333.55 kJ/kg = 521.5 kJ/kg. So the water/Ice should still outperform the mixture by at very least 2%. I do not know how he exacly measured the heat capacity (it's not shown in detail in this video), but I have serius doubts about his results. There could be the chance that Ben mixed something up with enthalpy of fusion and specific heat capacity, because thats two different things to consider for practical application (for a PCM we're interested in the enthalpy of fusion and not the specific heat capacity since the temp stays around the same at the operation point). Also the water bath test seems to have no stirring inside the bottles. When using a themal cam, one can see how extreme the temperature difference can be between top and bottom. Without stirring, this is just a ball-park figure. For precise tests, I would consider something calorimetric with a known source of heat (like a resistor driven by a bench top PSU) and a very good isolated container for the mixture and then let the test run over many hours, to be sure that the heat is spreaded evenly across the mixture. FIY: I've cooked some PCM with his reccipie (by weight) and doing some testing while writing this. So far (after 3h), I can see some PCM magic going on, but I cannot see the "18°C" pleateau that I'm looking for.

[@Scapeonomics]

@TimNeumann yeah, the mixing of the tests probably affected results.

[@MikeCNC]

I am also curious how much of the additional ability to soak up heat is simply due to the extra mass rather than the PCM crystals. The water itself is not undergoing any phase change and the mass of the water is a lot higher than the mass of the dissolved salt. How well does a similar constructed "seat cooler" do with an equivalent mass of gelled non-PCM salt in comparison?

[@darwinandvicki]

This was a great find for me. I am 77 years old and have a terrible time with the heat during the summer in Arizona. I always wondered why we couldn't make something that would become cool like the things that we have with the little metal disks for heat. Now I see how to do it. I will be making several of these of different sizes. Thanks for the info. I also am one who likes to learn something new every day.

[@SpaghettiToaster]

Did it work?

[@za0za_0]

I've started watching this channel like 10 years ago and I'm blown away by the increase in quality each time a new video drops

[@CRneu]

The quality increases but the comfy-ness and personality don't, which is great.

[@revhappymv]

Yes. Also it's still the same friendly, slightly awkward Ben after all these years. My favourite channel of all time.

[@TheFiddleGuy]

I am a delivery driver, and you have saved my life rn man. definitely gonna create a few PCM items with your recipe. Awesome work, keep up your amazing research

[@6Hans6Belphegor6]

Watching this for the same reason, ive been freezing salt water in gatoraid bottles

[@kf8113]

Would love to hear if you have any updates on this!!

[@alexmcaruthur6966]

UPS and fedex and Amazon don't care about their drivers only packages delivered

[@__shifty]

@@alexmcaruthur6966 duh, they're running shipping companies not therapy

[@noob78]

Sorry for my ignorance, but dont you have AC in your vihacle?

[@M.Campbell]

I think this is the most useful thing I have seen on KZbin. I have an immediate need that this will meet. I care for a feral cat, who is friendly when outdoors, but totally unsuited for living indoors. I need something to help her keep cool this summer, when it reaches triple digits. Making her a "cool box" with a PCM pad, or two, should do it. Thank you.

[@TheAzidahaka]

try wafering the pcm bags between some osb boards, maybe with a small door or a tent to limit the exchange of temperature. Let us know the results

[@SRavenSabbath]

Frozen water bottles might help too- that’s what I used to do for my rabbits

[@rodmills4071]

Don't know who writes your scripts, but your logical way of presenting each subject means you can listen to you speak for the entire video.....good work as usual...🤔😎🇦🇺👌

[@GPN007a]

For every 10,000 or so ai clickbait/celeb gossip/flat-earth level stupidity videos on this platform, there's one or two actually educational and very helpful videos like this and I appreciate these so much.

[@ngut5915]

You've got the numbers wrong, there are orders of magnitude more of the useless ones...

[@DevideNull]

If you spend seconds clicking [don't recommend channel] on each junk channel they will disappear from your youtube in a few days

[@JesusSaves86AB]

Dang, another ball lover. Wonder why we can't have live footage from all around the gloob considering the interest and billions spent annually (66.6 million per day by Nasa alone. They also own the worlds largest recording/special effects studio which they rent out for movies).

[@ct6502c]

​@@JesusSaves86ABHere is one of those flat Earther nuts 🙄

[@LennyMiller739]

​@@ct6502cIt's a bot.....

[@meetv7700]

This man is single handedly trying to help the world.

[@grim1427]

Never noticed them in any store before.

[@Sniperboy5551]

@Mr.N0.0ne He’s still educating people about science and DIY stuff.

[@andersjjensen]

@@Mr.N0.0ne Never ever seen that, and google tells me (because you can burry a crime on page two) that they've mainly been sold as pet cooling mats or laptop cooling mats. Neither are items I would have given a second glance, as both are fields where you can find 50 hoaxes for every legitimate item.

[@Nosweat99]

There are others

[@MAJRRD]

He is

[@Thirtyfivepercentferal]

I have no idea who you are, but you're my new hero. Once in a while YT recommendations are a real win.

[@erikabailey7397]

As a person with MS, I have a hard time regulating heat--I overheat in the summer, and my core temp drops in the winter. I made a batch and went to my camp (no electricity, road, cell service) and this stuff is amazing! When overheating, I put a baggy of the stuff on my back between myself and a chair--the steady cooling brought me back to the correct temp MUCH faster than previous methods. Thank you!

[@Nighthawkinlight]

Glad this is some help to you!

[@cookiedawg6977]

I love that you’re actually just a modern day inventor. I think a lot of kids want to be inventors when they grow up which obviously isn’t a real job, but you’re out here just actually making a living inventing doodads and innovations

[@cookiedawg6977]

I just had an idea also, I wonder if you could incorporate this into a neck wrap like the ones that use a sort of crystal you add water to to keep cool.

[@saintjohnny45]

​@@Mr.N0.0neHe brings this and the science behind it to the general public and shows people that they can do this themselves.

[@Jasoninee]

​@Mr.N0.0ne I searched "sodium sulfate dog cooling mat" and honestly no... it is not really like they are all over the place. Took me a bit to even find one mentioning gel, and it doesn't actually say it has sodium sulfate or even a pcm in it. It just says it is a gel.

[@Juttutin]

​@@Mr.N0.0ne *several years But yes, the only reason that they are not described as 'phase change gel' is that doesn't help sell them to your average pet owner.

[@Juttutin]

​@@Jasonineehow else do you think they work lol!! Physics is physics, if you have a blanket that cools things below ambient without refrigeration, it has to be phase change. Most dog owners don't care how it works.

[@yland6003]

Reach out to the Chillow Pillow Company! Currently their pillow liners need to be chilled in the fridge before use. They could use a PCM for better results.

[@Jeff-ss6qt]

Only downside is that they'd take the idea, patent it, and it wouldn't be available to anyone else without deep pockets unless they live in Germany. It wouldn't be possible to stick it in the public domain immediately.

[@maficstudios]

@@Jeff-ss6qt It already is in the public domain. This video nukes any ability to patent it, inept clerks at the patent office notwithstanding.

[@Jeff-ss6qt]

@@maficstudios Good to know.

[@RENO_K]

​@@maficstudiosyeah they'd have to modify the ingridients greatly to be able to patent it

[@kingmasterlord]

​@@RENO_Kwith how general he was with the details I'm not sure even that would be enough. xantham gum example he also said 'thickening or gelling agent'

[@bentuttle9170]

Phase change materials are already saving lives! Portable coolers designed for keeping blood at a very narrow temperature range while in the field for days at a time use PCMs. The temperature range is so accurate that some ambulance services that are now carrying blood keep their whole blood and/or blood products in the portable containers continually, simply swapping out the PCM panels on a regular schedule of in-use, cooling, and conditioning.

[@Noodle999]

Specifically this has allowed air ambulances in the UK to start routinely carrying blood. A game changer for trauma victims.

[@alexcampbell492]

I was part of a Community Paramedic program in Canada. We tried all sorts of solutions to keep expensive lab reagents at room temperature in vehicles that operate in -35°C to +35°C. We found phase change packs to be the best solution - even vs very expensive temp control devices.

[@GertvandenBerg]

Is that wax-based ones? (a friend was working at Siemens and they were shipping x-ray sensors with bottles of wax for PCM temperature regulation)

[@h8GW]

@GertvandenBerg You reminded me of the wax-based cooling solution the lunar rovers used

[@GertvandenBerg]

@@h8GW LEO satellites can probably use them as well to deal with the swings between being in the sun and the shade...

[@howardcohen2767]

I made pouches with 1 cup of this SCM each and took them with me to Burning Man. I put froze them in my icechest by placing them on top of a block of ice. I put them under my hat to keep my head cool and suck heat away. I found that a one-cup pouch lasted about 90 minutes in the desert heat. I was working hard and it was about 95º F outside. I swapped them out when they thawed. I needed at least three of them to work through the hottest part of the day, swapping as needed. I used seal-a-meal/foodsaver bags and none of the failed. I made about a dozen packs and gave them away as gifts to others who were working. These will be a permanent part of my Burning Man survival kit going forward because they work extremely well, are inexpensive to make, and are very safe should they fail. Thank you for this video - it made a big difference in my ability to cope with the heat.

[@Nighthawkinlight]

Thanks for sharing your experience!

[@SnekInTheGrass]

Just made a batch of this stuff and this stuff is so much weirder than I expected it stays cool for so much longer than you'd think possible. I feel like a alchemist following something out of grimoire instead of dissolving salts in water. Thank you very much for posting this video I just need to figure out how to encapsulated something like this to a dry state and make a pillow out of it.

[@HighVybeTribe]

Cool reference to alchemy!!

[@sebastiang8634]

Mate, I think I have the solution to your dry state encapsulation, if you are willing to spend a bit of money. There are Purple brand pillows out there that have a hollow section due to how they are designed. And because of the material structure of the pillows themselves, they are really good at getting rid of excess heat. By making a gel and soaking a small towel in it, and then sealing that in a silicone shell, you could essentially make a cooling core for a pillow. And technically speaking it wouldn't even need to be bonded to a towel if you were able to fully seal a silicone bag. However, I don't know how this would work with more traditional pillow stuffing, as that tends to be really insulating. Myself, I am more interested in figuring out how to incorporate this into a cloak or nondescript undershirt for when I am wearing armor. It might bulk me up a little more, but staying cool at Ren Faires would be a worthwhile trade off.

[@matthewsalmon2013]

​@@sebastiang8634 I think you just get the vest and drop your 65°F PCM packs in there.

[@SkyfighterZX]

A pillow that stays cold, now that's something i would like

[@sunoncream1118]

use aluminium knukle to have in hand while u sleep XD they gonna extract heat from ur hand and help to dissipate it XD u can also just put bottle of water in the freezer and sleep with them too ^^

[@HighDesertOffgrid]

Many of those who lived during the popularity of waterbeds can attest how uncomfortable one is when the heating element fails. Even during hot summers, the mattress absorbed so much body heat, sleep was miserable. Making a perfect PCM for the human body could be a breakthrough for those that can't afford ac.

[@caustinolino3687]

​@@sunoncream1118wtf is an aluminum knuckle?

[@JFirn86Q]

@@caustinolino3687 It's a popular statue made out of aluminum of the character "knuckles" from Sonic the Hedgehog. If you look it up you'll see what I mean.

[@jshaw4757]

​@@caustinolino3687 Ever watched transformers cartoon as a kid or the movies ?

[@jessl1934]

Xanthan gum is notorious for clumping when it hits moisture. When it's used in modernist cuisine, the main techniques to avoid clumping are to run the liquid in a blender and add the power while it's running or to disperse the xanthan gum through a powder or oil and to add that mixture while stirring vigorously. I'm not sure if xathan gum clumps may affect your recipe with regards to efficiency or composition but I thought it would be worth mentioning. Also food-grade vacuum bags might be a good way of sealing these pouches in a more permanent way. You can also make vinyl pouches and seal them with an iron - there are guides on how to do this for DIY hand warmers using sodium acetate.

[@Nighthawkinlight]

The xanthan gum dispersed surprisingly easily in my mixtures. No clumps after just a minute or two of whisking

[@r.anthony]

You can also first mix the xanthan gum in just a bit of oil. It does not clump in oil. Then add the oil/gum mixture to the water

[@AutoNomades]

@@r.anthony Really ? But one tume the powder is oiled... Will it mix with water then ?

[@r.anthony]

@@AutoNomades yes xanthan is often use in homemade soap if i remember well. And they use to mix it in a bit of oil beforehand to prevent clumps. If you use just a little oil (not a pool of oil) to dissolve the xanthan i beleave it will mix with water. It's a bit like mustard in "sauce vinaigrette" (oil and vinegar don't mix, but mustard act as a bound between them)

[@engineerncook6138]

As I remember it (from a class I took in1977), slimy substances (gums) like xanthan, guar, CMC are polysaccharides (long chains of sugar molecules) dissolved in lots of water. Mucus and fish slime are glycoproteins (proteins with attached oligosaccharide chains (short sugar chains) side chains dissolved in lots of water. In solution, these long molecules loosely bond to each other by hydrogen bonds creating loose network filled with water molecules. The network increases the viscosity of the gum or glycoprotein solutions. Hydrogen bonds are electrostatic in nature. The presence of ions (from dissolved salts) interferes with hydrogen bonding between the polysaccharide or glycoprotein chains. The PCM being tested is a mixture of solid Na2SO4.10H2O, solid NaCl and a saturated solution of Na2SO4 and NaCl so there is an abundance of ions (Na+, Cl-, SO4- - ) in the liquid phase to interfere with hydrogen bonding. So, I am not surprised that the xanthan gum behaves differently in this PCM than in the extremely dilute xanthan gum solutions most people have experience with. I use table salt to wash fish slime off of fish and my hands or to wash CMC off my hands. If you have some gums, test the cleaning power or salt for yourself.

[@mrn1ce6uy]

I'm an ER nurse. I was a new nurse when therapeutic hypothermic treatment was first being used with cooling blankets and cold water pumps. It didn't really do much as far as evidence based practice; we still used ice bags placed onto major arterial areas (femoral, bracial, carotic). But the evidence of hypothermic cooling was already there; the science was based on people being pulled out of frozen ponds and they recovered. So what you're experimenting with may have something to do with why this works. One of the things they teach us in nursing school is evidence-based practice; it takes 17 years for a new concept to gain regular use. That's a long time, but it has to start somewhere. Keep going.

[@sphygo]

As someone who works in a shop with basically broken AC and a boss that refuses to fix it, *I need this* I only wish this video came out last week. It was hovering around 90 all week and I would have been very glad to already have these made to test out. I'm sure we will be getting more hot days though, so I'm buying all the supplies tonight and will get to testing next week. Thank you for all your hard work in figuring this out!

[@MadHatter11371]

Boss needs to be fired

[@sphygo]

@@MadHatter11371 I agree, but unfortunately my boss is brothers with the owner, and HR is the owner's wife...

[@jdsd744]

What you need is a swamp cooler if it is an open-air shop, if it is not, fix the ac. This will not store enough -cool charge- as he calls it; to cool you all day. It just won't. You will be heating it constantly with your own bodyheat and the heat of the sun and outside will be heating you. You will be spitting into the wind.

[@bmanpura]

3 things stood out about the property of this thing that may be good for household application. 1. Not really free but absolutely cheap if you have the equipment and access to the ingredients. 2. You won't get frostbite handling a lot of this. Which is useful.. for a lot of stuff. 3. It's all food-grade. May, or may not cause condensation which is pretty nice for.. a computer. My laptop went above 70 every time I do game, and I've been using ice in tin boxes for spot cooling. If I can shape this into a satisfying cooler, me and my fridge may grow a bit closer. I'm from Indonesia, I'll try making this. If I get different result, I'll post a comment again. Thank you for this extremely interesting project.

[@allaboutlife4950]

im here in USA florida and my pc gets a little over 92 c sometimes

[@trueriver1950]

WARNING: you will get frostbite handling this if you chill it all the way to the bottom, as demonstrated in the video. If worn with a layer of clothing between you and the chill-pack, then chill it in a domestic fridge (NOT freezer!). For prolonged direct contact, I would suggest chilling it down to no cooler than 15C (46F). Things cooled to below about -1C (30F) will stick to you on prolonged contact; and below around -5C (24F) become a serious frostbite risk due to the numbing effect making you feel they are actually warm; and what is worse they may be stuck fast to you by the time your realise.

[@bmanpura]

@@trueriver1950 Ah, true. Thank you for the reminder.

[@pearlrival3124]

@@trueriver1950 in all fairness. it should jump from from 5F to 65F rather quickly. most likely within the the first hour of ambient.

[@ILoveTinfoilHats]

​@@allaboutlife4950 your CPU gets to 92° not your whole computer. This is not useful for cooling a CPU, as it does not extract heat it merely absorbs it.

[@Rogermonkey]

My father and I are both science teachers that mow grass commercially in the summer. I believe we are going to make some of these for use during mowings. Thank you for this awesome information!

[@MrWisski]

I made a batch of this stuff (Sodium Sulfate + Tablesalt + xantham). It's awesome. It recharges ANYWHERE with decent AC! It keeps its cool for a good long while, and its cold enough to cool you, but not cold enough to make you freeze!

[@masu5000]

He got a tenth of the subscriptions he deserves...

[@ke9tv]

I remember waaaay back in the 1970s, seeing a design for efficient HVAC by pumping heat into and out of a high-heat-capacity vessel containing a phase change material (I think it was ammonium nitrate-water). The difficult issues were phase separation and slow heat transfer into and out of the tank. The thermal conductivity of the material was very low, and it didn't convect when cold. Lots of improvement since then! (My local high school has a geothermal HVAC system.)

[@leifhietala8074]

The passive cooling of solar panels was a new concept. Combine that with the shading it provides to a roof and you've got a 1-2-3 punch that produces energy, reduces consumption, and improves function of both the panel and the structure. The only downside is the added weight. This is seriously interesting stuff, major daydream fuel.

[@NoSpamForYou]

Heating of solar panels in cold winter climates to prevent severe voltage spikes could be another use. It may let people get one more panel in their series strings or allow cheaper mppt charge controllers pushed to the limit safely instead of leaving a 25+ % buffer to prevent over voltage frying the charge controller. A lower target with less summer cooling would be necessary in northern climes. That or switch PCM pads for summer and winter which would be a pain...

[@0my]

As long as it gets cold enough at night. And hopefully during the day the extreme heat doesn't last for too long. Very cool

[@jttech44]

One step further, make a mechanism so that the panels can flip over, exposing the PCM panels that are coated in radiative cooling paint, that way, they start below ambient, and, the mechanism would also provide protection if you're running solar someplace that has hail storms. You could also do something similar with the roof panels, just move the panels from inside to outside with the sun, let them bleed off heat into the atmosphere instead of back into the structure.

[@chaoselites3636]

Hi, Ben. I just tried making this stuff and it is really fantastic. Thank you so much for sharing this recipe. I had a lot of success using kitchen vacuum bags and a sealer to hold the PCM as a cost efdective alternative to the silicone bags you mentioned. I hope this might help anyone reading who might also be interested in other ways to seal their PCM. I'm looking forward to any of your future vids. I try almost all of them and have a blast doing it so far.

[@humantwist-offcap9514]

As a chemist it’s really exciting to see such a GREAT explanation for non-chemists about one of the least intuitive (and most important) behaviors in thermodynamics.

[@gqh007]

Becoming the passively coolest channel

[@milkywaygamingtv]

I'm a UPS Driver in Arizona and this seems like an amazing thing to make. Thank you for posting your recipe.

[@bob15479]

There is zero doubt that his comment about “delivery drivers without adequate AC” was from seeing headlines about UPS lol

[@milkywaygamingtv]

@@bob15479 right? We finally got AC in our contract. Maybe we will see the AC in our trucks eventually.

[@milkywaygamingtv]

@bob15479 but until then I think I'm going to make that blanket thing to freeze every night and drape over my seat every morning before going to deliver all my packages.

[@annaleedaughterofyhwh7767]

And right now it’s 112* at 5pm 🥵. I can’t believe all y’all don’t have a/c in your trucks. That isn’t a luxury here but a necessity!

[@OmegaMale92]

I’m in AZ and ride my motorcycle to work. I’ve been trying to find ways to beat the heat while riding. 100+ degrees while geared up gets to feeling a little overwhelming. My ride is about 45 minutes and I spend a good amount of time afterward trying to feel normal again.

[@elementneon]

A Japanese company (and certainly others) has implemented PCM layers in the walls of thermoses to keep drinks hot or cold for long periods of time. I LOVE LOVE LOVE mine. It serves to keep ice blocks as solid ice for more than 24 hours in 100 degree weather, and my hot coffee I bring to work is still so hot at the end of the work day (which admittedly is not a great feature, turns out I prefer it at more of a drinkable temperature 😂).

[@nicellis44]

This is an interesting concept. Effectively using multi-stage PCM based cooling. I imagine that if you stacked layers of PCM's with transition points at progressively lower temperatures you could build a system that accomplishes extended-duration passive refrigeration/cryopreservation. Many vaccines go bad in less than a day without continual refrigeration, and require either single use short term coolants like dry ice or specialized vehicles for transport to rural or remote areas. A beach cooler sized box, with PCM packs rechargeable in a hospital freezer, and able to be tied to a motorbike or tossed in a jeep would be a game changer for public health in the third world. The Pfizer and Moderna COVID shots were effectively unusable in many African countries because of the refrigeration requirements.

[@SirBeaverton]

Would you mind sharing the name of the Japanese thermos brand? Or any other comparable brands? Thank you!

[@GregLescoe]

@@SirBeaverton oh wow yeah I'm in Japan and I've never seen anything other than vacuum flasks for this sort of thing, so I'd love to hear more

[@jonathanbutler6635]

Thank you for this. I drive a lot and don’t have great ac. I’ve been so hot I have to stop in the middle of what I’m doing and go into a gas station to cool off and stay safe. You just made my life so much better and safer.

[@dziban303]

maybe you should focus on getting your AC fixed instead

[@MrDjafal1]

@@dziban303 Comments like these won't help the individual person.

[@mxpants4884]

If your AC is working at all (check if the compressor starts spinning when you turn it on) then check the simple stuff: - cabin air filter If it works well if you're driving but sucks if you are at a red light, check for missing air baffles and make sure the radiator fan(s) turn on. The piece of plastic between the bottom of the radiator and the front bumper is important for airflow through the condenser. (Where a phase change of refrigerant is happening.) Also, check the outside temp readout on your dash. If your car believes it's too cold it won't turn the AC on. The sensor (and its wiring) is usually in the front bumper and can be damaged in accidents. If you are low on refrigerant charge, ask the shop to change the valve cores and make sure you have the plastic caps on the refrigerant high and low ports. Edit: the plastic/rubber baffles at the sides of the condenser are also important too. Checking this stuff will also help your engine cool down, so it's a win/win.

[@jonathanbutler6635]

@@mxpants4884 thanks for all of that. Honestly the biggest problem is that I don’t have time to take it to a shop and I’ve checked everything I can without special tools.

[@doejohn8674]

For hot summers, this might also be very nice as a cooling mattress topper or a cooling blanket.

[@BliffleSplick]

I was thinking the same thing, and as heat domes are becoming more frequent as the world changes, it'll be needed more and more

[@gamingSlasher]

I appreciate that SI units are also noted so the rest of the world can follow along.

[@homberger-it]

Oh yeah! Weight units would have been more helpful than for volume, though. 1 Cup of Sodium Sulfate? What's the weight of 240 ml of it? For Xanthan Gum it's even worse :( I used 1,2 litres of water, 380 grams of sodium sulfate, 80 grams of sodium chloride and 17 grams of xanthan gum. Result is still cooling down, but it looks good.

[@pearlrival3124]

@@homberger-it i cannot get the salt to dissolve no matter how much water i add. is this to be expected? i used 400g sodium sulfate, 80g NaCl (calcium silicate) mortons salt, 1.2L water but added 500 more ML, 15g xanthan gum. he added this recipe to the pinned comment.

[@homberger-it]

@@pearlrival3124 calcium silicate? I used 80g of NaCl (Natrium Chloride = Sodium chloride = table salt)

[@grumpyalison4869]

For anyone wanting to make these, I've made a few batches and they're really satisfying, but USE TABLE SALT and NOT SEA SALT :P I used sea salt by mistake for my first two batches because I didn't realize it wasn't table salt and it had some WILD issues with separation once it started cooling. It still totally works as cooling packs, but the final batch consistency was more like... slimy chunks of fish in sea water... (compared to the jelly you see in the video). It was extremely weird XD I got some real table salt and that issue seems to have gone away completely. For fun, I put a batch of my janky sea salt goo in the fridge and then poured off the liquid and put it back in the fridge and it re-froze and became surprisingly thick. Still works as a cooling pack though, it just doesn't feel AS cold as the 'real' batch because it's closer to your body temp. Also it seems like you can add mica without any significant decrease in the cooling potential (that i could tell at least) but make sure you use colors designed for cold process soap or you could run the risk of them discoloring aggressively in the heat (I have some really gross brown goo that should have been purple lol. It looked like some horrific potato-gravy mix while cooking) Also also, for the sake of experimentation, I tried putting some expanding water beads into the mixture and they didn't really absorb the liquid (which makes sense because it's heavily saturated by salt and they don't play nice with salt). But I wanted to know lol. I've also been heat-sealing the goop into LDPE bags (which I have pieces of lying around from other projects) and they've proven to be very sturdy so far (you can do the same to ship fish or to just fill with water and make fun swirly mica waterbeds for hampsters, or impromptu ice packs. My plan is to make little mesh/fabric pouches with snaps so I can slip these in and out and recharge them in a cooler throughout the day. Thanks again for sharing the vid! T

[@pearlrival3124]

im having issues as well. cannot get the salt to dissolve. is it expected to settle at the bottom?

[@jeffclark9918]

I work at a homeless shelter and I can't help but think about how awesome a chest freezer full of those cooling towels would be.

[@polandturtle]

Indeed, also the outdoor construction people. It comes up for truckers too, they can keep a little propane heater to survive cold weather breakdown but hot? A little plug in peltier cooler with an outfit of this would do it.

[@creativemetalworker]

I take the one gallon plastic water bottles, the rectangular ones so they fit together in an ice chest, and fill them with very salty water. It takes a much lower temp to freeze them them, but the salt ice stays frozen for 3-4 days longer than the same amount of salt free ice in my cooler. Its easy to do and makes the ice last longer.

[@fjb4932]

To have a cat, feed a cat. Get up into the top 5% of the homeless pyramid, that's where the money starts. Volunteers are a dime a dozen ( but do 95% of the manual labor ). The homeless shelter here once had Two Presidents, one to run the shelter and the other Public Relations/ Fund Raising. Both racking in the money. Unfortunately the public got wise and they consolidated the positions. Churches used to take care of those in need, but once the Gov't got into the game the churches figured out they had other things to spend their dollars on. What a racket... ☆

[@haruhisuzumiya6650]

Gonna need a bigger Esky

[@kimberlywilber7723]

I tried this recipe! A tip: If you haven't worked with Xanthan gum before, don't be surprised if it doesn't thicken right away. Keep boiling it! HOWEVER: be sure to stir the pot every so often or else there'll be a terrible salt layer on the bottom and you'll have lots of scraping to do.

[@Mrdawhip]

I stirred and wisked the whole time. I'm not sure if I'm just doing something wrong or what. I followed the directions accordingly but still had a thick salt layer. Any tips?

[@dansv1]

I had the exact same issue. I stirred continuously. I wonder if too much water was lost from boiling.

[@kimberlywilber7723]

@@Mrdawhip I stirred for a while and accidentally walked away. When I came back, I still had a pretty big salt layer in the pot, but there was also goop. To fix this, I used a metal spatula to scrape the bottom of the pot clean. This dislodged the layer and most of it seems to have dissolved into the goop. Now my goop is pretty lumpy, but it still works fine.

[@sneakyomni]

Was there an odor when you made it? I'm hoping to make it today but I don't want to stink up the house. Unfortunately, no hot plate available.

[@dansv1]

@@sneakyomni There is a very slight odor from the xanthan gum. Kind of a vinegar smell, but only noticeable while stirring the pot. I don’t think it will stink up your house.

[@Alex-nl5cy]

These might be really useful for greenhouses, which can have very unstable temperatures during cold seasons.

[@Nighthawkinlight]

Yes there's a paper linked in the video description that mentions that use

[@christajennings3828]

Or even during warmer seasons, to reduce the fluctuations between night and day.

[@cupbowlspoonforkknif]

That's what I'm eager to try! There is one company I've heard of already that's doing it but the cost is absurd so if there's a DIY solution on the cheap then this would be a breakthrough in my books!

[@chuckredd9131]

Another idea...Years ago when solar was in its infancy, it was solar panels with 3/4'' copper pipe in a closed loop filled with antifreeze circulated pumped over the panels into a tank of water, (mine was 500/1000 gallons) heating it up and tied into the home hot water tank, pre heat the inlet water and a radiator mounted into the furnace to heat up your home. There are U-Tube flicks on making panels.

[@NightmareRex6]

@@cupbowlspoonforkknif dang still companys that atualy reward workers for helping them out instead just tossing them under and replaceble?

[@TylerDollarhide]

Thank you so much for this! I've recently started woodworking, which includes collecting scrap logs, and it's now summer in Texas. I was out yesterday at burn pile run by the county cutting logs to take home, and combined with the 90 degree weather, I was starting to suffer heat stroke after only 15 minutes.

[@nekomakhea9440]

Thermodynamics: *exists* NightHawk: And I took that personally

[@BloodyMobile]

Someone please make that into an image, I NEED IT

[@solokalnesaltam3015]

@@BloodyMobile x2

[@hootiebubbabuddhabelly]

I don't make videos but I'll definitely be looking into adding flow dynamics to this little gem! Both pneumatic AND hydraulic! SUPER interesting...

[@jonathanberry1111]

I have debunk Thermodynamics, let's start with Carnot's Efficiency. The percentage of Carnot's Efficiency is the same as the percentage of heat on the hot side that is above the cold side relative tot he total. So if it's 15% higher the efficiency is 15%, and it's 0.00001% higher the efficiency is 0.00001% and if the cold side is at effectively 0 Kelvin it's 100%! And this can be seen if you look at the ideal gas law, it predicts the same pressure increase from the same additional thermal energy input even a a Billion degrees per the ideal gas law! So the efficiency CANNOT be what Carnot claims, and what his number is telling us isn't efficiency, as the heat engine doesn't even get the rest of the energy it remains in the hot side reservoir.

[@BVLVI]

LOLOLOL Best comment!!! this made me laugh so hard it echoed in the house.

[@billyandrew]

This guy never fails to raise the bar, rendering the seemingly complicated into simple to understand terms and instructions. I first encountered his channel a few years ago, looking for ways to make salt water drinkable. It's my go-to channel that allows me to get a grasp on many subjects that would otherwise be beyond my understanding. Long may he continue to educate the likes of me! 👏👏👏👍

[@Jonboy37]

Made my first batch and am looking forward to making more. One concern I wanted to raise is placing a dignificant amount of this at roome temp into your frig or freezer. It will spend a fair bit of time near 65 degrees. It should be kept well apart from foods as nearby or touching foods could be thawed and sit at a temperature range that is unsafe for a considerable period. Great videos, looking forward to more!

[@TheBadAssNinjaDude]

as a resident of the hellish 110+ degree weather of the phoenix metro area, I'm making these for everyone I know. THANK YOU!!!

[@aplicatorgm]

First 10 minutes, and you basically explain everything that i need without any blabbering/story telling/whatever. Information you gave is incredibly efficient, and i love it. I wish they use your videos as learning examples for studens.

[@MaxWithTheSax]

PCMs are fascinating. I knew about their use for keeping heat (eg. melted wax) but never though about using them for cooling.

[@stephena1196]

I knew about latent heat from school many years ago, but it never occurred to me it could be so readily useful.

[@barongerhardt]

In America, we have been using a food safe PCM to cool drinks for a long time. One day Europe will catch on.

[@MaxWithTheSax]

@@barongerhardt We also have cooling packs in europe but I don't think most people realize it's a PCM.

[@barongerhardt]

@@MaxWithTheSax No pack needed. Just drop it directly into the drink.

[@epiphaner]

​@@barongerhardtwe already do that, we even make the ice cubes at home in dedicated trays. 😉

[@GonzoSaavedra]

I live in an horridly bad insulated house in the middle of nowhere in Chile. And this video gave me some hope of insulating this house. Here in Chile we have very strict codes for construction because of earthquakes. And the main problem for a gel salt based isolator in my opinion would be the weight of the panel... But maybe in a dense gel form installed on the floor you could help the heat drain from the floor on the concrete slab. There is a lot to unpack from your video, thank you so very much for this

[@no_dot_0_dash]

I've watched a few of your videos over the years, but man this one is the one. If we could have had safety vests and hats lined with pcm made as easy as this, life would have been so much more kind. It's cruel that this technology hasn't already existed on a mass scale. You're just a regular guy, doing science in a work shed. And here's the simple, easy to make, life changing material your experiments yielded! I'm just amazed!

[@LenKusov]

Phase Change Material saved me from heatstroke today, about the time you posted this actually. I work HAZMAT in a warehouse without air conditioning, it got up to 95 today, and I was taped inside a Tyvek suit with a gasmask on for 2 straight hours. Thank god for EZCooldown collars, those things are engineered PCMs that melt at 60 or 70 degrees (depending if you get blue or orange packs) and with it right around your neck, it makes stuff like that a LOT more bearable. Worth the price, the cheaper cooling collars they sell at Home Depot are evaporative ones and don't do ANYTHING in hazmat gear cause that stuff doesn't breathe at all, if it did then sweating would actually do something. Edit: Watched a bit further and those packs are probably a more precision version of this stuff, similar melting points and enthalpy and they're non-toxic and behave similar I think.

[@badmedic6]

First-round draft pick for every apocalypse team, ever... Great content! Thank you for the incredible education and innovation.

[@iexcedo6918]

Hey! I hope you see this. I made a batch of this stuff from the beginning of your video. I had my wife put 3 pouches on the back of a few of my shirts running down my back. It looks goofy but let me tell you. Working outside during this heat wave. ITS crazy how much it works.

[@Nighthawkinlight]

That's awesome! Thanks for sharing your experience

[@Ghostman719]

Maybe a couple of these packs in something like a bicyclist shirt with the built-in back pockets could work well

[@behr121002]

Ben, you share my name, resemble my brother-in-law, are very much like me in interests and approach, and a Michigander to boot (ostensibly, based on your hat?). You're one of the rare content presenters with a clear, cogent, articulate, information-rich, curisoity-rich, style which is much appreciated by this Michgander. Truly an intelligent, experimental citizen-scientist! Carry on my friend!

[@KlenKarter]

I think I know the reason why the graph looks like that. As the solution starts to crystalize, the remaining part of the solution has a different composition. The water that's left behind still has some salts solved in it, that's why you see it's cooling slower than the pure water, it goes under the freezing tempature of pure water because of the salts (principal of the freezing temperature decrease by the solved particles in the water). So it freeze around -8 Celsius. I hope it helped understand a bit more of the graph :DD Love your content!

[@joshuadelaughter]

I can't get over how good this channel is. Practical knowledge simply explained and easily achieveable and affordable for an average person. Just incredible.

[@curtlezumi]

Thank you so much for this tutorial. With your inspiration, I did a little research and identified a PCM recipe that has its transition slightly below freezing. Urea in water at around 28%-30% urea to water by weight ratio makes a pcm with a melt point around -9C or 16F. No more soft ice cream on 35C days.

[@PreacherGannon]

Literally half a second before you said "It's like flipping over to the cold side of a pillow" I was sitting here going "I want to make a pillow out of this stuff"

[@nekomakhea9440]

For re-usable personal cooling, maybe those home food preservation heat-sealed vacuum packs would work best? You can suck all the air out, and the heat seal seam on them to make them extra sturdy compared to the zip lock on sandwich bags, so they don't pop open if you accidentally lean against a wall and squish them. You could probably even partially overlay multiple heat seals over top of each other for an extra wide heat seal that's nearly indestructible.

[@that_rhobot]

I've done this before for a more traditional ice pack with water+alcohol. If you have a vacuum sealer with a pulse setting, it makes it easier to suck out the air without accidentally pulling out your solution and making a mess. Did the first heat seal as close to the liquid as I could, then two more each a quarter inch back from the previous seal.

[@SethCohn23]

combining with a shop rag or other 'medium', this seems like the best option.

[@nidavis]

@@that_rhobot also helps to hang the bag off an edge as opposed to laying it flat

[@LeonardGreenpaw]

I feel like this is channel gives more science than the actual full professional science channels I watch

[@elisabethellison3922]

Ooo! I would like to try this to fill my "freezer plugs" that I use to fill space in my RV fridge. Since RV fridges are notably slow to cool, subject to frequent re-warming when the vehicle is moved, and I have to minimize power usage since I'm on solar, what I do is cycle jugs of water from the freezer to the refrigerator. People did this decades ago at home and called them "freezer plugs." I've been scouting for more effective freezer plugs. I'll try your formula & let you know!

[@acolize8883]

This’ll be perfect for people like me who can’t sweat properly. I have lost track of how many times I’ve gotten heatstroke in the summer and I’m ordering the materials to try this out. Thank you for your work, this means a lot to me.

[@astrong0]

I work in a trauma center and use these BLUE HEAT endoscope warmers used in laparoscopic surgery. They are sodium acetate trihydrate and they get VERY hot. Very neat to see.

[@TaroutCommodore]

I've been watching this guy for years. Time well spent for sure. I thank you deeply sir.

[@demetriusgallitzin8859]

!!!!!!!!!!!!!!!!!! How much thought and planning did it take to explain this in the most concise and simple way possible, that academic papers would often discuss only in technical language with limited practical applications. Adjusting or seeking PCM to practical temperature ranges is really awesome.

[@maverickdovakin9786]

I'm imagining my car seats staying cool for hours on end. Without any ac running. This is awesome. W video

[@speendo]

I tried the recipe yesterday. Now I have the cool bag on my head since 4 hours and I expect to get some more hours of subtle coolness from this bag before putting it back in the fridge. Really cool ❄😎❄ As Xanthan Gum is difficult to acquire in a local store at my place (Europe), I ordered and used CMC. I was really concerned that the gelling effect didn't work, because I didn't notice a difference in the viscosity of the liquid after adding the CMC when it was still hot. Maybe just a very subtle effect after adding about the double amount of CMC of what was recommended in Ben's recipe. Despite these concerns, I put the bags in the freezer over night, where they turned solid. After warming up to about 18 °C, the substance got this gel like texture that so many people in the comments (including me) are longing for. Therefore I recommend to first cool down the mixture before judging whether the recipe worked for you or not. For charging the bags in the fridge, some other person in the comments recommended to take care that they don't touch any other food that needs to be cooled. I want to underline this thought: this PCM will keep the temperature of ~ 18 °C for many hours, no matter whether the environment is hot or cold. Therefore it will also melt (or heat up) anything that should be kept at temperatures below 18 °C (= everything you keep in your fridge or freezer). @NightHawkInLight: Thank you for this great instruction! It would be very interesting to know if one could fine tune the exact temperature of this PCM, e.g. by changing the ratio between NA2SO4 and NACL.

[@Nighthawkinlight]

Thanks for sharing your results! Yes I think the temperture can be tuned by reducing the amount of table salt, but I've not tested other recipes

[@speendo]

@@Nighthawkinlight Thank you so much for your reaction to my comment! At almost 6.000 comments I was not expecting an answer so fast :) I'm looking forward to your next creations!

[@RacecarAndChill]

As an hvac guy. I really want to see something like this for personal cooling. Like a hat or a shirt I can put on. The average attic temperature in phoenix during the summer is 150 degrees. Something like this could change the game. I think im going to make a towel sized one as a seat cooler in my service truck!

[@teamcybr8375]

That cooling vest he showed could work really well!

[@fayeprice5500]

Make a Towle one to put on back (hold in place with belts)

[@lanesaarloos281]

There are motorcycle vests for summer rides with protective gear. Got one at Cyclegear. Fully soaked holds 7 pounds of water, no drips after a few seconds. Good for 2 hrs or so unfrozen.

[@RacecarAndChill]

@lanesaarloos281 why didn't I think of this?? I know exactly what you're talking about!! I'll look into it right now! Thank you for taking the time to comment! Soaking that in my ice chest will probably make me cold on a 115 degree roof with a breeze!

[@BliffleSplick]

Someone else mentioned something like ezcooler tcm and it goes around your neck?

[@millroyboy07]

My man is making other people patent money in the name of science; the true nature of scientific discovery. I love it.

[@DaraelDraconis]

Oh, but he isn't. If anyone were to try to patent these things, the videos would be perfect evidence of prior art and prior publication, which would invalidate the patents! Anything you see published here which is not already patented is, effectively, public-domain. Forever.

[@millroyboy07]

@@DaraelDraconis Product manufacturing is tricky. There are minor changes to engineering and how things are named that allow people to commercialize on similar products. It happens all the time.

[@babybalrog]

To your question at 11:00. I just watched a video "Advantages and Challenges in Usage of Inorganic, Salt Based PCMs in Buildings - Prof. Jan Kosny" which looks like a uni lecture, and at 1 hour 10 minutes, he enters a discussion that I think answers your issue. Basically, even with a constant formula, different types of crystals can form. Hexohedral and tetrahedral for example. Which can have different entropy points. I suspected "crystals forming" was the answer to your chart, but didn't know how to explain it. The more interesting thing, his the solution provided, fixes the problem AFTER cycling a few times. So PCM can act differently first cycle vs twentieth. Something to know for future tests.

[@HealthyDisrespectforAuthority]

Early morning, before my caffeine levels reach optimum.. the word supermaterial in your title, looked to my -the sun's not up yet- eyes, like the word supernatural in my feed. I scratched my head and opened the tab. This kind of DIY doesn't quite fit in with the sewing videos I've been watching. This was fascinating. I think I need to go play in the kitchen now. I'll remember this stuff. A whole lot of understanding how things work depends on how information is presented. You started in just the right place for familiarity of concept. ^5

[@PropGuru702]

You never disappoint man... This is an incredible wealth of knowledge in a super palatable form. Kudos to you

[@masonkiel]

Grant Thompson from King of Random was the first time I had heard of PCM’s in one of his earliest videos. It played a part in inspiring me to become a mechanical engineer. It’s great to be reminded of him in one of his friend’s videos, years later :)

[@GunGryphon]

Excellent research, I need to see how well these will work in a cosplay. A handler could keep spare packs in a ventilated bag to cool off between uses.

[@NonJohns]

I'm sure there's research on where to put ice packs to cool off athletes I can imagine a preventative style of cooling by placing a pcm pack on such areas you've got a lot of covered up areas anyway... why not hide a cooling pack in there!

[@MayorOfLuckyBoyNV]

I was told that putting cooling packs around high blood vessel areas, like the neck, wrists and ankles is a good way to cool down. I was thinking about using these as wrist cuffs to keep cool

[@necrophage5248]

​@MayorOfLuckyBoyNV My grandmother worked in a mill and she would dip a rag or cloth in ice water and put it around her neck. I in turn when working outside in the summer would do the same. It's amazing how much just that would keep me from dripping in sweat. They have cooling neckerchifs now made w PCM's that require only water to activate but I stick them in the freezer for max relief.😊

[@DaveEtchells]

I have a phase-change neck cooler, a horseshoe-looking thing that I bought in Tokyo to stay cool. It does make a big difference in my perceived temperature but is a PITA to use because the material is quite rigid when frozen. This makes me wonder about cutting the plastic open, draining its contents and refilling it with this stuff.

[@JAYTHEGREAT355]

You can try by using two of this sheets and 3d printing a h9nycomb with gaps or gaps then sandwich them in and add a small fan . I read you're comment and I do cosplay costumes. I will try it this summer .

[@deandorris8479]

I have made several batches and have a couple of questions. How long should we boil it? And what should the consistency be afterwards? Does it become completely solid like ice when it is cool? Mine does not. It is about the consistency of thick pudding even straight from the freezer. Also, I saw comments about xanthan gum lumps. To combat lumps caused by the xanthan gum, I tried adding the xanthan gum slowly to the boiling water, which didn’t work. Neither did making a paste prior to adding it. It then required a lot of vigorous boiling to dissolve the lumps. On my third batch, I tried mixing the xanthan gum powder with the sodium sulfate before adding it to the water, and then adding that slowly to the boiling water. That worked well to prevent the lumps. As nearly everyone else, I enjoy your videos immensely even when I don’t try to do it myself. Thanks so much for providing meaningful, useful, and educational content, not to mention fun.

[@Nighthawkinlight]

Good tip on mixing the gum with the other powders! I didn't have trouble with clumping myself but it seems many others have. You only have to boil about 5 minutes for the mixture to work well. In a freezer the mix should be quite solid, in a fridge it should be like thick slush. If it's not freezing correctly the most common problem is that too much water has been added. You might be able to fix it by warming it up again and adding more sulfate.

[@deandorris8479]

@@Nighthawkinlight Thank you!

[@UltrasoundJelly]

Great video. I'm a nuclear engineer by education, emergency physician by training. One other angle to consider on the human-physiology side of cooling is that extreme cold (ice to skin) causes vasoconstriction, thereby limiting the ability to cool a person's core. A smaller temperature delta would theoretically be more effective at actual core temperature modification. Of course, core hyperthermia is what puts a person at risk for heat stroke.

[@BillColeman]

I use a phase change seat pad to recover from the heat. I sit on it while driving between gigs and it is amazing. Here is a DIY version that is actually better than the commercial version.

[@imstupid880]

It's crazy how Ben started as a KoR-type channel so many years ago and now he's dropping chemical wizardry with a reverse sodium acetate pack. Man really needs to start hitting up the patent office.

[@danielescobar7618]

What is kor

[@yusufyilmaz5317]

@@danielescobar7618 King Of Random, another youtube channel that made(haven't watched them fo a while so i don't know if they still do it) interesting stuff.

[@imstupid880]

@@danielescobar7618 King of Random

[@TDubble0]

@@danielescobar7618he’s referring to the KZbin channel King of Random. Before he passed he made a lot of similar content. Sadly the people who took over his channel missed the mark.

[@AdroSlice]

Well no, the more of this open, accessible to the public and free of intellectial property lawy the better.

[@carl902]

This is probably the most valuable DIY video on youtube

[@starr_ship]

I could see this being insanely helpful for greenhouses in places with big temp swings between day and night.

[@glass4600]

Or on tractor trailers that are moving perishable goods so it doesn’t heat up as fast?

[@transistordave]

I'm a Canadian, and used to work outside a lot. About 12 years ago, I saw some people selling those PCM heaters with the snap disk. I bought several, and used them for a long time, keeping my hands warm in the harsh Canadian winter. This is a very interesting technology; I never really thought about its other uses before!

[@mojocosmetics]

I've tried to find something for years that could keep me cooler in the summer with zero results--super excited to try this. What an amazing discovery, thanks for the share!

[@tedr35]

I followed your recipe with only one suggestion...make a roux with the xanthan. Much like corn starch, it tends to clump in the heated liquid.

[@KennethFinnegan]

Sodium Sulphate on its own makes sense when you look at its solubility in water curve vs temperature, so it's the enthalpy of solution that's working for you here, not its standard enthalpy of fusion like you'd expect given the name "Phase Change Material". That solubility curve is also absolutely wild, and I just ordered a 5lb bag of this stuff to play with like you. The addition of NaCl is interesting, and I wonder if there's a good "eutectic-like" chart for how that ratio modulates the solubility curve. The fact that this is a PCM of solution also explains why you don't see a single melting point like you'd expect in a pure material or a smear of melting point like in an alloy; just a shallower curve than water the whole way down because the heat of solubility is adding to the specific heat of the water you dissolved the salt in.

[@somecsguy9824]

Finally got around to trying this out. It definitely works and it's so cool. I had some chunks in there I couldn't smooth out -- some being the sodium sulfate and some being the xantham gum -- but it turned out to be no big deal. It's probably because I dumped the scoops into the pot rather than slowly pouring them out as I stirred. Next time. It's definitely a subtle coolness, but totally enough to feel good on a hot day. Weirdly it took me making this stuff to fully understand how it works. It's basically spreading the cooling energy of a typical ice pack over a long period of time, at the cost of it being less cold. Which is good. No one likes an ice pack sitting on their skin for more than a couple minutes at most. And getting it so close to a comfortable temperature is genius. Sure you could make it 60 degrees, but it would probably feel more uncomfortably cold after a while (like sitting in front of an AC vent for too long, even on a summer day you start to get the chills). Plus it would warm up more quickly. It's really surprising that this stuff isn't more widespread. I know it's already a thing, like you said, but I feel like it should be way more common in hot/humid areas, which I live in. This is the first time I've heard about this type of thing.

[@lunarminx]

I plant to make some today with my grandson, I am going to throw them in ziplock storage bags, double it up and duct tape it closed and tape a few together to make a large one that can fold like a paper fan to recharge daily in the fridge for bedtime!