Technology Connectionslet's learn why Peltier devices are not actually very cool in this new video:
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Solarbird 
@TechConnectify Did you see that LTT video like a year ago where they tested the latest attempt to use this effect for CPU cooling? It was also terrible. ^_^
Wheeze_NL@moira "there is alia video on the topic" should never be a reason not to make a video 😊
@wheeze_NL That's not what I'm saying, though - I mean, the use cases being described are completely different. It's more a YEP THEY SURE ARE TERRIBLE xD kind of thing.
The only reasonable use case I've found for any peltier cooling kit has been as a replacement/augmentation for a passive cooler in a car. I have one, it _wasn't_ a super-cheap model (tho' I got it for free via credit union rewards points) and so it's actually not loud even with its fan. If you throw in a small plastic-wrapped ice block on top, you get many, many hours more useful time out of a portable cooler. So if you're on the road for hours (in our case, if you're a touring band on the road), it actually becomes useful. And he talks about that.
@moira I am sorry for misinterpreting your message.
They suck indeed
Tobias@TechConnectify Thanks for doing videos and thanks for still engaging here :)
@TechConnectify I looked into these years ago, but never ended up trying it. Looking forward to checking the video!
Luís Correia@TechConnectify some years back, i replaced a peltier module on a "box fridge" for camping uses
it's desing was way better tehn that fridge, because it had a cooler and fan on both sides of the module
insulated with expanded foam and all, it "kinda worked", good enough to keep cool beer on the beach
(actual cooling done on car battery on the way there)
Legally Distinct Basilisk@TechConnectify I just agreed to take one of these fridges from my parents, who'd gotten one to keep drinks cool while their kitchen was under renovation. If I'd seen this first I would have said "don't bother."
One question I had, though. If Isobutane's boiling point is around 45°C, does that mean that in extreme situations your refrigerator can just get too hot to function?
@BasiliskXVIII Yes but not for that reason.
When the ambient temperature goes up, the refrigerant can't shed heat as quickly which results in the condensing temperature increasing. Since the system is filled with pure refrigerant, condensing temperature and pressure are perfectly correlated so the end result is the high side pressure goes up enough to raise the boiling point enough to keep functioning.
It's only a problem when the pressure exceeds design limits.
@BasiliskXVIII I don't think you'll ever see that happen in a domestic refrigerator, instead the compressor will start to overheat and its thermal safety switch will start kicking in. Enough cycling of that switch will eventually kill it, though.
When it comes to large heat pumps for heating and cooling, there are pressure switches which prevent the system from operating if the pressure gets too high (or in fact too low, depending on the protections you want).
@BasiliskXVIII (left this out)
When the high side pressure goes up, that makes the compressor work harder. So power draw starts going up and more heat is generated in the compressor windings.
That's really the limitation of any refrigeration system. As high side pressure goes up, eventually the compressor is working too hard and generating too much heat to keep working without stuff breaking.
@TechConnectify Thanks for the insight! I'd just been reading about Paradise Nevada hitting around 120°F, and that number being so much higher than the refrigerant's boiling point surprised me.
Tevruden Dawnspear@TechConnectify I offer you the following, if you have to explain the refrigeration cycle in a video not about it: "The LaCroix of brief."
InsertUserThe smallest compressor I've ever "seen"* was the one for Adam Savage's cooling suit. It probably could cool something the size of the little blue thing.
*well, on video
Adam Savage's One Day Builds: Refrigerated Cooling Suit!
monorail times@TechConnectify can’t beat physics
Josh Grosse@TechConnectify time to add a connextras discussion of garage-ready fridges. 
Michael Cook@TechConnectify Another great video. I always assumed those little desktop fridges didn’t work very well (though it sounds like they do better than I thought.)
I had no idea they used Peltier elements. Never would have occurred to me they were less efficient than a full real fridge.
ENG. Tretron 🐲@TechConnectify also those extremely small cheap toys have another issue that is just amplifying the issues you discussed. And that is the have the squarecube law against them, they have an insane amount of surface area to absorb heat from compared to the volume where as a large fridge benefits from having large volume compaired to surface area. So when you scale up something it takes less and less energy to keep something cold.
jenbanim@TechConnectify I actually ran into these in one super niche use case where they were useful. At an astronomy observatory I was at for a bit they switched from cooling the CCDs with liquid nitrogen to using Peltier coolers. Even with the inefficiency, it was far cheaper than hauling liquid nitrogen tanks into the mountains, and didn't require nearly as much maintenance
Pianosaurus 🕴@jenbanim @TechConnectify Electronics engineer here. This is where they really shine, but it's not a use case you see much in household appliances: When you are cooling very small things, Peltier devices can keep things cold without having to move a lot of energy.
Typically, even for ICs, they are bad (but CCDs don't generate a lot of energy, luckily). I've been using them to cool down photon detectors (used with some _very_ niche optical systems). Those detectors get very hot, but they are also micrometers across in size. At that scale, it doesn't take many watts of cooling power to cool it by over a hundred degrees C.
Cassandrich@pianosaurus @jenbanim @TechConnectify Untested but suspected useful application: maintaining ultra low humidity in an enclosed environment using wicking action to move the condensation to hot side and evaporate it off outside enclosure using the heat.
socks@TechConnectify south Illinois persona screaming "I'VE GOT A GIANT AMERICAN FRIDGE" is going to stay with me for a long, long time
Jernej Simončič �@TechConnectify Just curious – how thick are the walls on that cube fridge in the video, they looked very thin to me? I've got a similar fridge at my weekend house (where I just happen to be at the moment), and that one has 55 mm walls (the fridge itself is 45 cm wide).
@jernej__s The are indeed thinner, about 30mm
Alex Hall@TechConnectify Fun and informative, as always. I have a question about a comment you made about your big fridge, though. You said the bottom freezer was a knock against it. I thought the freezer being on the bottom helped to keep cold air inside when opened, reducing the energy needed to re-cool the freezer. Why is a bottom freezer a bad design? Thanks.
@alexhall A chest freezer holds onto air, yes, but anything with a slide-out drawer will spill out all the air every time you open it.
But that's not the main issue, it's that US fridge designs use a single evaporator in the freezer and the fridge is simply fed air from the freezer. Top-freezer models get help from the air in the freezer being denser so it mostly just falls in through a baffle which opens and closes. Bottom-freezers needs fans to push air up and into the fridge compartment.
@TechConnectify I had no idea. Thank you! My fridge is similar to yours--bottom drawer freezer and two doors. I always thought it was more efficient because of the freezer being on the bottom. Now I know that's not the case.
Andre Louis@TechConnectify @alexhall We have a big Kenwood fridge-freezer with the freezer on the bottom as is common, always wondered why I hear fans sometimes.
LB@TechConnectify the whole time I was about to tell my wife: "told ya, I was always for the compressor-cooler for when we go on vacation with the car" and then you said the peltier ones are okay for exactly this use case. Damn...
Still thanks for the video!
gunstick@TechConnectify I wonder how this device works. Something with heat pipes?
https://youtu.be/6kw4B-8ez1M
https://youtu.be/6kw4B-8ez1M
hk@TechConnectify I had a good laugh over how you addressed possible comments by us europeans early. 😁Very good execution.
I was a little bit disappointed that you didn't mention radio radioisotope thermoelectric generators,though. But I can see why that might be a off topic. Still my favorite use of peltier elements.
I was a little bit disappointed that you didn't mention radio radioisotope thermoelectric generators,though. But I can see why that might be a off topic. Still my favorite use of peltier elements.
Ewong@TechConnectify I thought the rule of thumb for these was that they'd keep a beverage about 20⁰F COOLER than the external temperature. I'll check this out to see if you found out the same thing.
enoch_exe_inc@TechConnectify Ah, these things. Without looking it up, I can already tell it isn’t very efficient. The thermoelectric effect just isn’t.
steelman@TechConnectify Fun fact: Peltier elements work the „third” way too — they can turn temperature difference to current (and work).
Great video, thanks.
Weird 2 - Electric Boogaloo@steelman @TechConnectify yep. High temperature thermometers use this effect to measure temperature in industry settings. It's pretty nifty in these cases.
Tobias Klausmann@TechConnectify I will love you forever for skibidi heat pump.
That is all.
leckse@TechConnectify If the noise level is a concern: An absorption refrigerator is actually silent.
Forgi @ TFF 
@TechConnectify I was honestly not expecting them to be that inefficient...
Huh... TIL.
Huh... TIL.
My name is Gordo@TechConnectify Enjoying this as we speak. As a relatively new home owner, your obsessive interest in the minute details of the seemingly mundane aspects of modern living has been a continuous source of joy, or at least provded some comic relief (I want to murder the people who designed my dishwasher (it's a Bosch. Yeah, I know; I expected so much from that name), and my fridge, which I already expounded on in the YT comments lmao)
Andrew Price@gordoooo_z @TechConnectify
I had two Bosch dishwashers and they were the worst I've ever owned. They both developed identical leaks in the bottom tank after less than five years in operation - clearly an uncorrected design fault. Replaced by an Italian machine from INDESIT which not only cost less but has been problem free for over seven years.
I had two Bosch dishwashers and they were the worst I've ever owned. They both developed identical leaks in the bottom tank after less than five years in operation - clearly an uncorrected design fault. Replaced by an Italian machine from INDESIT which not only cost less but has been problem free for over seven years.
@andrewprice @TechConnectify I don't know how old ours is, because it came with the place, but while ours doesn't actively leak, the door latch is so convoluted and nonsensical, that it is possible to close the door to a degree that the controllers thinks it's closed, but that it is not sealed enough that steam won't escape, condense under the lip of the countertop, and end up in a puddle across the kitchen floor. There's like a shaft that goes from the front of the dishwasher under the top...
@andrewprice @TechConnectify ...rack, to a thing in the back of the dishwasher, and that appears to be how it determines if the door is closed or not??? Also for a while, the door just wouldn't close, because the thing that mates up to at the back was dislocated, so I'd have to shove my arm all the way in, lift it up, then quickly close the door?
It's... unfathomable. My parents' white Frigidaire from the 1997 was probably bottom of the range, simple as they come, and functioned continuously...
@andrewprice @TechConnectify ...for over 20 years.
@andrewprice @TechConnectify ...UPHILL! BOTH WAYS! IN THE SNOW! 😅
Spitfire@TechConnectify always enjoying your vids. thank you :)
Mac - VA3WFT@TechConnectify This would be great for a McDLT.
Lockpick Extreme
Faysal@TechConnectify Yet again, you've saved me from making another stupid purchase
Pixol22@andary @TechConnectify I saw a thermoelectric fridge that looked like an Xbox One. And there was another that was built like a Minecraft Creeper. 🤣 I don't think people buy them for the fridge part.
Juho MäntysaloI loved the yankee-fridge part, had to rewind to laugh twice, thank you!
And now that I'm writing, thank you for rememembing us in the 230W-land, with our SI-units and stuff. Always makes me fuzzy.
Watching anglosphere-content, sometimes it feels like you're the only one who does. I want to say how much it means to me!
simonbp@TechConnectify Nice.
Another niche application is small astronomical cameras, which often have a small thermoelectric cooler to keep the sensor chip cool enough (ie 0C for visual band, cooler for IR). Great for that because you only need to cool a tiny thermal mass. But even then, the cooler often draws substantially more power than the rest of the camera+telescope mount combined, which can be an issue when you're powering it with a battery in the field.
Anthony Horton@simonbp @TechConnectify And, increasingly, some not so small astronomical cameras too, e.g. https://www.princetoninstruments.com/products/cosmos-family/cosmos
Admittedly those COSMOS cameras need both an internal thermoelectric cooler and an external water chiller, with the water cooling being used to carry the heat away from the hot side of the thermoelectric stack.
shironeko@TechConnectify I have no idea how common this is, but there are water dispensers which uses a TEC for their function, since they are heating the water on one side and cooling it on the other, it's a pretty neat use case.
I learned this when I was a kid and our school have these super cheap top-loading dispensers and it feels like they are 100% made of plastic, so TEC being so cheap must have been a factor as well.
I learned this when I was a kid and our school have these super cheap top-loading dispensers and it feels like they are 100% made of plastic, so TEC being so cheap must have been a factor as well.
Tommy Hanusa@TechConnectify Are Peltier devices used in ships or airplanes or other vehicles where weight is a concern and the vehicles movement could also dive circulation of air/water against a radiator?
too many names
Dofain@TechConnectify oh c'mon, you can't say that Peltier are not very cool and leave at that, that's quite cold of you.
Robots can be gay deal with it@TechConnectify All the fridges they sell in truck stops are thermoelectric, and they suck! They even sell one that looks like a normal cube fridge, and has some kind of refrigerant heat pipe situation but it also is just a thermoelectric pad. They're so power hungry, they melt the 12V plug they come with!
But, they do make real refrigerators that run on 12V DC and they have gotten much cheaper. This one I have is designed to be jostled around and tilted, you can even get a bag to put it in with shoulder straps and a battery. I love this little thing, and I'd say the extra space needed for the compressor is made up for by the fact that it can get room temperature water bottles frozen in less than 3 hours.
Dr. Blazing@TechConnectify SIR YES SIR 40 MINUTE VIDEO ON SOME TECH I'LL NEVER USE!
rai@TechConnectify "skibidi heat pump" at the end has killed me.
Thank you for the always wonderful captioning! It's always fun to see how you transliterate vocal fumbles in the bloopers, and we always look forward to seeing what kind of smooth jazz we're being treated to.
caranea@TechConnectify Remember testing a Peltier CPU cooler with a Cyrix MediaGX in the shop back in the late 1990's. The system shut down after less than a minute due to the CPU overheating. Turns out the cooler almost melted its wires due to the power draw, and the fact that it was a great insulator didn't help matters when it just couldn't shuffle the great away fast enough. The CPU was okay after cooling back down, but we banned Peltier coolers from the shop floor after that.