Exploring Below Ambient Water Cooling

[Motopsychojdn]

Always have a good time at the Rock and Bike fest
I did mention tools cables as well on his log, I thought he'd have done better tbh knowing me as he does 😛
Moto

 

[4Ryan6]

What groups played?

 

[4Ryan6]

Very interested to see the write up w/ pics! Nice work...very neat to see it performed beyond your expectations.

😱 Oops! Umm, Those are the pics, I should have taken more detailed pics before I insulated it, like during the assembly phase of everything but was too busy working on it and concentrating on the task at hand to take pics in those stages, definitely My Bad!

I have to admit it's nice not having to add ice to the cooler haven't even opened the cooler for 2 days, the water temperature inside the cooler has not been above 16C since this project began, the present temperature is 13.8c and dropping.

Some of what needs to be shared is the peltiers what I call weirdness, I originally thought the cooler I kept the hot side the cooler the cold side would be, however the hot side has to get hot for the cold side to get cold, it is a perfect example of, "For every action there is an equal and opposite reaction.".

There was quite a bit of testing and fan changing to get the peltier to run at it's optimum cooling side capability, at one point I actually had the hot side too cool and it was not performing as expected, it's been a learning experience that's for sure.

This peltier was designed to be slapped on a CPU, not cooling a 10 gallon cooler, so there was and is a big learning curve here, to adapt what it's actually capable of doing to my needs.

The peltier is a remarkable little piece of hardware, to me it defies logic to some respects, it was basically designed to have the hot side cooled by a standard closed loop water cooling system which would be operating usually about 3c above ambient.

So the true key to this things performance is give it the heat range it was designed to operate in, and it will give you the results you're looking for, if that makes any sense at all.

Bottom line, It needs to be in the mid range of it's capabilities, so it's hot enough to deliver the cooling performance, but far enough away from it's limitations to keep from burning it out.

I guess from all I've covered so far from the time I started this peltier project the best forward progress is are there any questions? Ry

 

[rubix_1011]

The thing that surprises me most is that it actually performs worse if you cool the TEC too well. I never would have thought that to be the issue, but looking at the principles it operates on, it does make a bit of sense.

As for the pics, I must have missed them once you posted them...I went back and looked. Quite an impressive looking cooling (tower?) you put together.

What would you do differently if you were to start the project over? Is there any part of the project that you'd like to engineer differently/better for overall installation or performance improvements?

 

[4Ryan6]

The only thing I would have done different, knowing what I know now, is, I would have done this a year ago!

 

[rubix_1011]

What kind of temp results do you see when you use the ice jugs AND the TEC together?

 

[4Ryan6]

What kind of temp results do you see when you use the ice jugs AND the TEC together?

Garrett I haven't used any ice at all since I started running the peltier.

 

[Motopsychojdn]

What groups played?

The Sweet, Toyah Wilcox (Yeah, I'm that generation hehe)
Oc/Dc
Megadeath
Rammlied
X-ufo
Sack sabbath
G'n'r experience
Quireboys
loads more but my program is somewhere in our bags, oh hang on...
http://www.rockandbikefest.co.uk/

its a couple of 'real' bands and a hell of a lot of really good tribute bands, Rammlied, Sack sabbath and Oc/Dc topped it for me that side of things, once the barrier is shaking and the crowd heaves, you wouldn't know it wasn't the real deal
\o/
Now to see what next years event brings,
I do love the scene, even though its more festival than bike rally the last couple of years, its the one thing that we do get to attend (other halfs health prevents us straying too far from home)
Moto

 

[rubix_1011]

I haven't been to a rock festival for a few years, although it seems we have similar taste in tunes. I'm a classic rock/metal/hard rock kind of guy.

 

[jrwizbang]

Wow. Pendulum. That's the only one I saw. Didn't bother looking at anything else. Saw that Pendulum is there. I approve.

 

[4745454b]

"the Island". Great song. Not rock/metal though...

The only down side to the TEC that I see is that 200W+ heat being dumped into the room. Temps on the PC are good but what about the room? Nice in the winter but summer much be a bit rougher.

 

[jrwizbang]

"the Island". Great song. Not rock/metal though...

The only down side to the TEC that I see is that 200W+ heat being dumped into the room. Temps on the PC are good but what about the room? Nice in the winter but summer much be a bit rougher.

One of my favorites by them is the Island, along side Witchcraft and Salt in the Wounds. Great band.

 

[4Ryan6]

The only down side to the TEC that I see is that 200W+ heat being dumped into the room. Temps on the PC are good but what about the room? Nice in the winter but summer much be a bit rougher.

Because of the sunlight directly hitting my office window 80% of the day I had to install a window AC unit to keep the room tolerable, so I run the AC anyway even in the winter sometimes, presently the added heat is not a problem.

Without the AC however it would be a problem the peltier does put out constant heat, should be nice on really cold days, but last year we really didn't have much of a winter at all in South Carolina, very few really cold days.

 

[4Ryan6]

The Sweet, Toyah Wilcox (Yeah, I'm that generation hehe)
Oc/Dc
Megadeath
Rammlied
X-ufo
Sack sabbath
G'n'r experience
Quireboys
loads more but my program is somewhere in our bags, oh hang on...
http://www.rockandbikefest.co.uk/

its a couple of 'real' bands and a hell of a lot of really good tribute bands, Rammlied, Sack sabbath and Oc/Dc topped it for me that side of things, once the barrier is shaking and the crowd heaves, you wouldn't know it wasn't the real deal
\o/
Now to see what next years event brings,
I do love the scene, even though its more festival than bike rally the last couple of years, its the one thing that we do get to attend (other halfs health prevents us straying too far from home)
Moto

Good grief! Why so many tribute bands?

Was it a no budget concert?

Not enough money to pay real groups?

Never really understood the purpose of tribute bands?

They cannot make it with their own music so they play others?

Whatever!

Reminds me of Hollywoods movie industry, they cannot seem to come up with a new idea so they constantly remake old successful movies!

Not trying to be disrespectful to your rock festival experience Moto!

Megadeath is the only group I recognize in the list, and I'm not a fan of theirs either!

Best concerts I ever saw live:
Led Zeppelin
Grateful Dead
The Who
Alice Cooper
Kansas
Eagles
Boston

Theirs more I don't recall at this time.

It's hard these days to top the old groups would have loved to have seen, Queen (before Fredi Mercury died), or the Doors, or for that matter Michael Jackson, before he died, the lost singers voices are unmistakable and historical legends.

I'm a classic rock fan obviously, not dissing your concerts man just remembering and reminiscing.

Still don't get tribute bands though!

Always in the other groups shadow?

They remind me of THGFs gimme a quick fix overclockers! :lol:

Going forward on someone elses work!

Whatever! Ry

 

[4Ryan6]

For those interested I'm presently conducting water level experimenting, it seems I no longer need 10 gallons of water so I've removed 4 gallons from the cooler to see how less water performs.

I'm testing for a water level range that a constant water temperature can be maintained, there are always CPU load variances that affect the balance so I'm searching for a happy medium, so to speak.

This may lead to using a smaller cooler because of the amount of air left in the cooler?

May actually be able to drop to an insulated reservoir?

However that may not be enough water?

Questions?

 

[4745454b]

I could sorta see a reason for a tribute band. Either the band doesn't exist anymore, or they don't tour. Like a Glenn Miller band because they are dead, or because AC/DC doesn't tour much anymore. I'm still trying to figure out what Pendulum was doing there....

Not sure how much water you can remove. Last reported temps were up around 13c right? If they get 10c higher then you are at room temp. (not that its a bad thing.) Smaller res is always good of course.

 

[4Ryan6]

Not sure how much water you can remove. Last reported temps were up around 13c right? If they get 10c higher then you are at room temp. (not that its a bad thing.) Smaller res is always good of course.

???Less water means the peltier has less volume to cool down, so it cools it faster, temperatures go down not up.

 

[cbrunnem]

???Less water means the peltier has less volume to cool down, so it cools it faster, temperatures go down not up.

and like you alluded to early the opposite it true. with less water it will heat up faster.

 

[4Ryan6]

and like you alluded to early the opposite it true. with less water it will heat up faster.

alluded to?

Where exactly did I say that?

with less water it will heat up faster.

How could you possibly come to that conclusion?

The peltier is located on the return side of the CPU loop just before emptying back into the cooler.

The peltier is not just neutralizing the heat the CPU adds to the water flowing through the CPU water block.

It is actually lowering that heated water below what left the cooler to start with.

Facts:

10 gallons of water at 15hrs run time the water temperature in the cooler dropped 2.6c.

6 gallons of water at 7hrs run time the water temperature dropped 3.4c.

3.4c in less than half the time with less volume.

 

[cbrunnem]

alluded to?

Where exactly did I say that?



How could you possibly come to that conclusion?

The peltier is located on the return side of the CPU loop just before emptying back into the cooler.

The peltier is not just neutralizing the heat the CPU adds to the water flowing through the CPU water block.

It is actually lowering that heated water below what left the cooler to start with.

Facts:

10 gallons of water at 15hrs run time the water temperature in the cooler dropped 2.6c.

6 gallons of water at 7hrs run time the water temperature dropped 3.4c.

3.4c in less than half the time with less volume.

if the temps drop faster why can they not heat up faster?

 

[4Ryan6]

if the temps drop faster why can they not heat up faster?

No Offense!

Do you understand whats going on?

Simple explanation the peltier is constantly cooling, it is keeping the water in the cooler from heating up.

It not only keeps the water from heating up, it lowers the temperature of the water in the cooler while it's running.

Understand?

 

[rubix_1011]

Best case scenario, the TEC is running at 95% TDP capacity and cooling 230w constantly. CPU at 100% load and 95% TDP might introduce 150-160w of heat, but this is technically intermittent as your CPU never remains at 100% load for 100% of the time, where the peltier is constantly cooling at the load it is set to run at. The ability to offset heat by removing more than is being introduced is the primary principle at play in this scenario.

 

[cbrunnem]

No Offense!

Do you understand whats going on?

Simple explanation the peltier is constantly cooling, it is keeping the water in the cooler from heating up.

It not only keeps the water from heating up, it lowers the temperature of the water in the cooler while it's running.

Understand?

ok so under full load does the water start to warm up?

 

[rubix_1011]

Even if the CPU is running 100% TDP and let's say it's dumping 160w at full load into the loop, the TEC is still removing 230w at the same time. At idle, it's still removing 230w while the CPU might be adding only 100w.

The cooling ability of the TEC always surpasses the heating capacity of the CPU in watts at any point of the CPU load curve, this is why he is seeing even lower temps with less total water volume; the frequency at which the water cycles past the TEC is increased linearally as you decrease total volume meaning the more frequent the contact it makes with the TEC and removing more heat than is being dumped in the loop.

In a perfect world, if you removed enough water to drop the (total water volume)*(specific heat of water) you could theoretically continue to drop temps until the TEC reached it's delta similar to how radiators do.

 

[cbrunnem]

Even if the CPU is running 100% TDP and let's say it's dumping 160w at full load into the loop, the TEC is still removing 230w at the same time. At idle, it's still removing 230w while the CPU might be adding only 100w.

The cooling ability of the TEC always surpasses the heating capacity of the CPU in watts at any point of the CPU load curve, this is why he is seeing even lower temps with less total water volume; the frequency at which the water cycles past the TEC is increased linearally as you decrease total volume meaning the more frequent the contact it makes with the TEC and removing more heat than is being dumped in the loop.

In a perfect world, if you removed enough water to drop the (total water volume)*(specific heat of water) you could theoretically continue to drop temps until the TEC reached it's delta similar to how radiators do.

how efficient are the Peltiers? im just trying to soak this device up.

Edit: it looks like after a few minutes of googling that these devices have a low efficiency so that goes back to one of my original questions, 4ryan6 have you discovered any situation where the cpu is heating faster then it can cool?