Thermoelectric Cooling is a Bad Idea

[AlexTheGreatish]

People keep emailing us saying “Hey Linus, you should look at Peltier Coolers!” – and I’ve finally given in, so here is a video about why it’s a bad idea.

 

Buy Noctua NH-U12A:
On Amazon: https://geni.us/I3D4qI
On Newegg: https://geni.us/BuXVBCP

 

 

[wellend]

Cool! Dat "solder job" though 

[Razor512]

I wonder, how about adding a peatier cooler to the reservoir of a traditional water cooling loop, so that it dissipates a little extra head from the loop that the standard radiator misses?

 

The heat transfer in liquid cooling works almost linearly in terms of speed, the larger the temperature delta the faster it cools, for example, a  360mm radiator will not cool a a smartphone SOC to ambient, it will get close but as the deltas get smaller the amount of surface area needed to get closer to ambient increases exponentially.

 

To increase the delta in liquid temperature, why not cool the reservoir with peltier?

[hui]

Editing felt... off on this video. Like it was overdone in places (the music and the cinematic modes being 2 examples)

[Bitter]

I wonder if the bottle neck on the TEC setup is the poor water blocks on the modules? If that water block is just a hollow cavity with no fins or anything inside of it then it's not so much a demonstration of TEC's being unable to provide the cooling capacity but a demonstration of poor water block design being unable to provide the cooling capacity.

Thoughts? Maybe @AlexTheGreatish could cut one open out in the shop to see just how terrible the blocks are inside and swap on some better blocks to see if that changes anything. I understand the 500W monster TEC is coming but if it's water block isn't any better it won't be able to pull anywhere near the 500W of heat out of the water that they claim it's capacity to be. I'd also love to see the TEC's tested against the sellers claims to figure out how many W of heat they're actually handling, Alex can use his calculator.

[Nystemy]

The problem with peltier devices is that most people don't even know what they are good for, how to actually drive them, and how their efficiency curve even looks.

 

Peltiers aren't really good at "cooling", in terms of cooling high power dissipating devices, like a CPU. For somewhat similar reasons to why chucking a PC into a fridge is also a fairly bad idea.

 

Not to mention that applying 12 volts to them and not taking their max operating voltage into consideration or the fact that they are fairly current driven devices can lead to overvolting them and thereby quickly killing . Then there is overheating them, most peltier devices will not survive temperatures above 60 degrees C. (this varies depending on the type of Pelteir, some go to 80, others 140.)

 

Peltiers are primarily used for temperature regulation of lasers, primarily for laser physics, medical, and even telecommunication. (the wavelength a laser diode outputs is directly effected by its temperature, and the wavelength can be very important in prior mentioned fields.) In these applications, large amounts of power aren't typically expected. Peltiers can also be used in cooled CCD cameras. (the sensor noise of a camera is proportional to its temperature and the quality of the amplifier as well.)

 

In the end, a Peltier is mainly useful in applications where one can't have a big refrigeration unit around, either due to space, weight, durability reasons. Or if one desires to get to far bellow sub ambient in just a few stages. And primarily in low power applications. Or if one desires to temperature regulate a laser to within a few hundredth's of a degree C.

 

For PCs, Peltiers aren't all that useful.

[TetraSky]

It's unfortunate that this type of cooler just doesn't work in reality for PCs.

[Streetguru]

Why didn't you go do a proper chiller loop with the 2 peltier coolers? CPU->Radiator->Chiller-> CPU?

|

[Nicnac]

Alex is really keeping ltt alive! Great job!

[SolarNova]

1 hour ago, AlexTheGreatish said:

People keep emailing us saying “Hey Linus, you should look at Peltier Coolers!” – and I’ve finally given in, so here is a video about why it’s a bad idea.

 

Buy Noctua NH-U12A:
On Amazon: https://geni.us/I3D4qI
On Newegg: https://geni.us/BuXVBCP

 

 

You've likely already made the next vid but none the less....

 

I hope you go into using more than just 2 TECs or even 1 really powerful one.

 

They run far more efficiently at lower power, and they are not expensive so u use multiple smaller TECs for high heat load situations instead of a single high power TEC at max.

 

When it comes to cooling the hot side, when using only a few then air coolers can be the better option in regards to cost... but..

Lets say you have 10 TEC's to cool, buying 10 aircoolers could cost what....$350. You can build a cheap water loop for the hot side for that and it will run better. 10 extra cheapo blocks + a few Aluminium rads, a DDC pump and a small res.

 

You can also try stacking TEC's however you will need a beastly primary TEC running at very low power so that the next TEC in line can handle the heat of the primary TEC, and so on. The Max heat load thus is smaller than running a single TEC but the Delta is far better allowing lower temps. So if ur aimng for a high temp delta this is a way to go...Power usage however gets crazy.

 

[greenhorn]

Interesting video but I kind of expected those results (having played around with Peltier elements myself years ago).

What puzzles me a bit is the question why Alex and Linus decided to solder those cables together instead of just using a wire stripper and some wire clamps (from Wago for example). That would have resulted in less hassle, probably better connections and easier disassembly after the project.

[AlexTheGreatish]

34 minutes ago, Streetguru said:

Why didn't you go do a proper chiller loop with the 2 peltier coolers? CPU->Radiator->Chiller-> CPU?

If you want to go sub-ambient then the radiator is working against you

20 minutes ago, SolarNova said:

~snip~

The plan is to have a single 545W peltier with the cold side directly against the CPU (or maybe have a piece of copper between the two to help spread the heat) and then cool the hot side using a beefy water cooling loop.

[Bitter]

Beefy water cooling is only as beefy as the water block absorbing the heat if you're looking at short runs for max temp and not planning to heat soak the whole loop (then it's obviously the air/water interface that's the weak link). I hope you're planning to use some good blocks and not the janky stuff without fins inside.

 

Also, thank you for doing these videos, they're really interesting and while we're all criticizing anything you do it's just because we want to see more crazy content like this...or at least that's my reason. Explore ALL the possibilities!

[martixy]

There is an arrangement that can make these work...

 

The strength of Peltier modules is their ability to go sub-ambient.

So how do you utilize that?

Why, you'd need something with high thermal inertia capacity. For example water.

 

So... you make hybrid solution, a custom water cooling loop that at prolonged sustained load, when the heat output is much higher than ambient works as a normal water cooling solution.

But... at lower temps, close to ambient, the Peltier element kicks in and starts cooling the water below ambient.

 

So depending on typical workload, the thermal inertia of the system and how well it is insulated, you could end up operating below ambient a good deal of time, with significant leeway for sustained high-output payloads.

[AlexTheGreatish]

3 minutes ago, Bitter said:

Beefy water cooling is only as beefy as the water block absorbing the heat if you're looking at short runs for max temp and not planning to heat soak the whole loop (then it's obviously the air/water interface that's the weak link). I hope you're planning to use some good blocks and not the janky stuff without fins inside.

 

Also, thank you for doing these videos, they're really interesting and while we're all criticizing anything you do it's just because we want to see more crazy content like this...or at least that's my reason. Explore ALL the possibilities!

I'm currently working on getting some flow-sim software and simulating the whole thing to make sure it can dissipate 700W+

[AlexTheGreatish]

1 minute ago, martixy said:

There is an arrangement that can make these work...

 

The strength of Peltier modules is their ability to go sub-ambient.

So how do you utilize that?

Why, you'd need something with high thermal inertia. For example water.

 

So... you make hybrid solution, a custom water cooling loop that at prolonged sustained load, when the heat output is much higher than ambient works as a normal water cooling solution.

But... at lower temps, close to ambient, the Peltier element kicks in and starts cooling the water below ambient.

 

So depending on typical workload, the thermal inertia of the system and how well it is insulated, you could end up operating below ambient a good deal of time, with significant leeway for sustained high-output payloads.

Or you could just take a couple 4 gallon jugs, fill them with anti-freeze, and then toss them in the freezer for a couple hours.  Take them out, sub them in for your radiator in the water cooling loop and presto - sub-ambient for a long time without having to buy peltier modules and using a lot less energy.

[DemonicTaco]

This video felt off. Like Linus wasn't too interested in it or something. The ending was weird.

 

Video was hard to follow, and it seemed like the editing was weird.

[martixy]

3 minutes ago, AlexTheGreatish said:

Or you could just take a couple 4 gallon jugs, fill them with anti-freeze, and then toss them in the freezer for a couple hours.  Take them out, sub them in for your radiator in the water cooling loop and presto - sub-ambient for a long time without having to buy peltier modules and using a lot less energy.

Or that... but that's the best idea I have of making these things remotely practical.

I mean you can always attach a heat pump(e.g. compressor) directly to the loop and skip the just in the refrigerator part too.

[Jotoco]

I did a research for the inverse in college. 

 

By adding an extremely thin Peltier array between cpu and cooler you could recover a sensible amount of energy. Something to the tune of 7 to 9%.

 

If that is underwhelming, think huge datacentres with hundreds of thousands of kW being consumed at once. 

 

 

It could be huge. 

 

Mostly we needed thinner peltiers, but my research was done 12 years ago, technology and materials must have evolved by now.

[Razor512]

I was thinking that instead of trying to go below ambient, why not have a peltier there to deal with more extreme situations. For example, when it comes to radiators, you can get diminishing return.

 

 

But even in those situations, if you take a standard air cooler, and pipe in the cold air from an air conditioner, you can drastically reduce the CPU temperature without a delid.

One situation I wonder is what if a peltier can be added somewhere in the loop with its own heatsink and if just there to add around 50-60 watts of heat transfer in order to possibly deal with a scenario where the 360mm radiator is handling a good overclock just fine, but then you hit 95C under an AVX workload, and at that point the additional peltier can add a little extra active cooling to probably knock that temperature down 5 or more C.

[Bitter]

Oh yea, that would be cool but it would still be cheaper to just add more radiator than it would be to have a demand based TEC to add cooling?

[eisenklad]

Coolermaster V10  used an extra cooling tower for a TEC/peltier... that was 2009.

 

living in humid singapore, i abandoned my idea of peltier cooling since dropping to sub-ambient would be catastrophic .

as for this recent video, those aquarium chillers is for those that dont AC their fish room or for leaving their house for extended periods(compressor based one are noisy or may fail in more than just cooling).

and an aquarium isnt a Heat load so keeping PCs chilled on the long runs of gaming/ rendering marathon is never possible. 

 

my idea/delusion was to actually have an external loop coming out of the case. on it, i would sit a peltier and the hot side would be a copper framework shaped into cup holder that would be used to keep my metal cup of coffee warm while adding cooling to the cpu. but that was a disaster waiting to happen to i just have instant coffee and a small electric pot in my room.. 

 

but instead of a peltier, i also thought the external coil could be used as a Reusable Ice Pack dock...basically when you need to emergency cool, you take a pack out of freezer and place it on the dock. basically its like putting PC in the fridge without actually doing it. i almost did it with a old xigmatek tower style  aircooler but i shifted away from janky looking pc ideas. i have ziptied large fans to my core 2 Duo pc case before.

[Sharko987]

Over the last couple months I've been messing around with TEC cooling CPUs just because fun. After binning and communicating with some of the modern TEC manufactures I found that the best TEC was the Laird Thermal Systems ET15,24,F2,5252,TA,RT,W6. It is actually a cheaper high temperature variation of the ET15,28,F2,5252,TA,RT,W6 which is rated for up to 46v at 15A. I 100% don't recommend this for any system that is being used for work however I set it up directly attaching it to a i7 940 (I don't want to kill new hardware) and overclocking it so I could get the heat up to about 300W or so (its pulling that from the EPS connector). Then I set the hot side to be cooled by a dual 360mm radiator cooling setup to cool the heat, this could be improved because the water temp would sit at around 30 degrees even after 5 minutes. The whole cooling system pulled about 900w from the wall on a separate 1000w psu hooked up to a different breaker from the computer.

 

This video was interesting because along with derbauer this is the second video I've seen with TECs recently and since this is a series and I happen to just live in Coquitlam I was wondering if you would like to have some of my prototypes? I am still excited to see where you take this regardless but if you would like I can drop them off.

 

Looking at this forum post I also would like to post a response to Alex's most recent post about refrigerating anti-freeze and say; what is really fun is taking that sub-zero antifreeze and using it as coolant in the peltier system for some extreme sub-zero cooling adventures :P. CASCADE REFRIGERATION

[lewdicrous]

Der8auer did something kinda similar, maybe you can fix whatever problems he had in your next test and/or learn from him.

Spoiler

 

 

[OSKrueger]

In my opinion the physics here is used in the "wrong direction". Instead of cooling there should be energy harvesting from excess heat.

 

Stay with conventional cooling and throw those Peltier-elements in reverse! (TEC vs. TEG)

 

Put TEGs in series on the VRM , chip set, GPU, CPU heat sinks,… and maybe there will be enough energy to power some RGB lights

(If you put those to #00FF00, you will have the greenest green you’ve ever seen. ).

 

If you want some real black magic for your cooling, try the cold end of a vortex tube.