DIY Supermaterial Could Save You From Heatstroke: Salt based PCMs 

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! If you'd like to support these projects directly you can do so through Patreon: www.patreon.com/NightHawkProjects Thanks for watching! -Ben

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.

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

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.

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.

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

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 has been experimenting with Glauber's salts for many years.

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

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.

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

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

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

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! 👏👏👏👍

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.

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.

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

You are one of the few channels on RU-vid 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.

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

This man is single handedly trying to help the world.

This is the most underrated youtube channel ever 💁‍♂️.

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!

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.

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.

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.

The wierd temperature slope I think makes sense because it is a solution with stuff in it and not just a pure liquid. Something similar happens when you make ice-cream, if you put ice-cream in a freezer it will slowly solidify as it gets colder, but it doesn't all freeze at one temperature. Physically I don't know the fancy terms for it, I am sure there are some, but I believe what happens is that water's freezing point will be lower with stuff dissolved in it, which is why you salt roads in winter, so the water will remain liquid at lower temps, but when you cool it down, eventually some of it will freeze where the concentration of the dissolved stuff is locally lower, probably at a molecular scale, and as this process happens the concentration in the remaining liquid become higher and thus the freezing point becomes lower, this keeps happening until eventually all the liquid is solidified. I also think the test you did after where you warmed it up in a waterbath with circulating water might not be great unless I misunderstood how you did it. If you warm them both up in the same bath you don't really know which one retains heat energy better, water is an excellent conductor of heat, it can absorb a very high amount per weight and because it is a fluid it can circulate it around and easily mix it throughout. But the other mixture is gel-like meaning it will have much worse heat-conducting capabilities because it doesn't flow around due to convection as easily. So when you have both in the same bath, you could figure out how much heat it takes to melt them together, but that could be that ice took 60% of the energy and the salt mixture took 40%, meaning ice would be better at storing heat energy. I would guess it's actually very close to 50/50, because in both bottles you are freezing water and I don't think the phase change energy depends on dissolved stuff, it just happens at different temperatures, if anything the salt solution has a little less water because of the dissolved salt so it would probably take slightly less energy to completely change phase.

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

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.

Thank you for all of the great videos over the years! I genuinely believe that it's people like you who genuinely make society better just by being yourself and somehow always get left out of the history books. Keep making practical applications of science accessible, fun, and free. Somebody get this man a cape!

Your channel is always one of my favorites. No fluff, easy to understand, and a pleasure to watch.

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

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.

We need to spread this information far and wide. You are performing a public service!

This answers every idle wondering I had when “recharging” PCM heat packs in still-hot leftover cooking water this last winter. So many thanks from blast-furnace Texas for a fascinating and practical series of materials science videos, especially the iteration for fully passively cooling these packs - I’m already sharing your content online and look forward to sharing my results locally.

I think this is the most useful thing I have seen on RU-vid. 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.

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.

I was really impressed with this video. My plan is to use this for cooling my butt on long drives. Great work. Thank you for all your hard work.

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!

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.

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

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!

The thermal video of water freezing just blew my mind. I knew the energy involved, I just never imagined it would be so visible to the camera. As someone who runs very hot, I will definitely make some of the gel! Thank you so much, your videos are always extremely educational, and super practical!

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

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

This is so cool and actually useful. I've been watching your videos for over 10 years now (!), and I'm still amazed by your ingenuity.

Thanks so much, Ben, for doing such a great job of putting all this data and info together… And then sharing it with all the rest of us for free.

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.

This is probably the first time I'll try to make any of your DIY projects at home. Living in south-east asia, last summer the temperature went up to 41c and direct contact with the sun will knock you out within an hour. I'll take anything to keep me cool, preparing for next year 40c.

Thank you, Ben! I'm amazed by how simple this method can be!! Going to start an experiment myself. You're the best educator on RU-vid!! 😀 👍

I’ve been hooked on to this channel since the PVC rocket from all those years ago. Still one of the coolest projects I’ve done as a kid.

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

It's just incredible the amount of -practical- knowledge you basically just give away for free! I watch tons of RU-vid 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!

I have ordered a bunch of stuff to start experimenting with this material. The possibilities are endless.

This is a topic I have always had a lot of interest in and I'm very happy you have made this video on them not only educationally but also in a way that's accessible to nornal folks wanting to learn and experiment

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

Becoming the passively coolest channel

Great stuff. The added details like dehumidifying PCM-stabilised structures really add a lot of practical value!

This feels like it came out of a group of mit students pr something! This video is a rare gem, and whenever I find something like this I often think about it for much longer and can't keep watching new videos. I'm going to show this to some of my friends!

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"

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!

Just found your channel, and I've gotta say, it's super cool. I've been thinking that technology based on thermal conduction and battery style storage and retrieval of heat would be a good approach to a lot of the problems we seem to be facing nowadays. So of course, I clicked this video when I saw it. Glad to see someone actually working with this sort of thing - and independently at that. I probably shouldn't encourage you to keep working alone, but as someone who aspires to do similar things, you are very inspirational. Seriously, I hope to become more like you over the next year or two. Thank you.

I cannot put into word how much I love you, man.

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

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.)

PCM are a perfect compliment to radiant floor/wall/ceiling heating and cooling. Great video Ben! Thanks!

Holy cow Ben. I have only skipped around so far, but this sounds as if it could be tantamount to an "on the cheap" earth berming of your home.... I'm so flipping excited!

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.

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

Just found this channel. Finally the algorithm gets something spot on. I absolutely love videos like this.

One of the most interesting but also useful channels love it!

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.

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

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!

This really is amazing info. Thank you for sharing!

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.

Well since water breaks for outside workers are no longer required in Florida, this could help a lot.

Just found a new favorite science/diy youtuber. Ty for sharing your knowledge and ideas/inventions with all of us.

This is amazing. I have no words... I just need to try it, thank you sir!

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.

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!

I honestly think this is revolutionary in every sense of the word.

My first exposure to your projects...impressive and yet so simple..

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!

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

Very cool, pun intended! I was very impressed with both the PCM education and your brilliant use of a pet to keep watchers viewing as you did your ad. It was effective, I watched the whole thing.

You are an incredible teacher. Making this kind of information accessible to the average joe is awesome. Thanks

This man is going to shatter the law of thermodynamics while giving us free step by step instructions to follow along with. 😂

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.

This guy is crazy in the best way. What a legend. Keep up the good work.

Yours is one of my favorite channels! Keep up the good work.

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.

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.

That's a great experiment series Ben! I really liked that as chemical technician (my first profession). In the past year I've been close to the PCM businnes, because our company turned to the industrial cooling applications and we cooporate with a Hungarian startup that started to grows with organic PCM materials. I had an idea from last summer to cool down my parents flat with a simple fan and salt based PCM that you showed here in the first part but the melting point around 25˙C. It always surprises me when several home experimenters are think in the same direction at the same time. Keep up your good work! BLADE

This is incredible work. You sir are a genius making things which are obscure accessible to the lay.

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

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.

First time viewer. WOW man, Instant subscriber. I even created a new folder for my Tube University content. I love everything about your video. Delivery, tone, visual representations and evidence all really capture my attention and keep it all the way through. I'm here for it. I appreciate good information and a no nonsense delivery of it. Bravo sir, thank you for your work and time!

You have a lot of cool videos, but this has to be the most immediately useful thing I have seen. Amazing!

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

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

man really, each one of your videos show such jawdropping stuff its crazy