Exploring Below Ambient Water Cooling

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Would it still be worth pulling it all apart and removing that plate if it does eventually cool it in your opinion? Would there be a big difference in the time it takes to cool the water?

Im only using around 1 litre in the loop i might look at insulating the XSPC res tonight.

Also what are your thoughts on using to much thermal paste? I didnt think it would matter that much since there isnt any sensitive parts to leak onto and the excess just oozes out when clamped anyway.
 


You remove the plate so the block doesn't freeze and so the flow rate is faster to pick up the cold.



The loop itself is using up the cold not storing it, I already tried using an XSPC reservoir and it did not work, and the one I was using did not have a heat adding pump in it.

As far as actual insulated reservoir you don't have much of anything there!



This is a far different use of thermal compound than application methods for a CPU, you have to have full coverage and the clamping pressure will squeeze out the excess, what I see in your pictures looks good to me.
 
In an effort to show all relevant learned to date TEC/Peltier cooling information I have created a floating thread however since we're soon to change to completely new software at THGF I'm posting a backup of it here so as not to loose it.

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

This thread is sharing information with you regarding Peltier/TEC CPU cooling, it is to bring those interested, or curious regarding this type of cooling, up to date on it’s cooling possibilities, and progress, and the setup pictured below is currently in use and fully operational.

Caution: Peltier cooling will allow you to go below ambient, depending on what your desires and goals are and how many peltiers you run, you can even go below 0c, it is possible using anti-freeze coolant. My initial goal was to be able to run below ambient just above the condensation forming point so motherboard insulation does not come into play. You can safely enjoy about a 10c below ambient without any condensation worries at all, but you take full responsibility with what you do with this information.

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If you’re interested in following the full journey of how this all came to be, it is in the Exploring Below Ambient Water Cooling thread.

What does this type water cooling allow:

I’m sure the first question would be why would anyone be interested in this type of cooling in the first place, and if you’re 100% satisfied with your present water cooling setups load temperatures, you won’t be. The main why is, it can run load temperatures, lower than the mass majority of your ambient reliant CPU big air coolers, CLC Coolers, Standard and Custom water cooling loop idle temperatures.

These comparative tests below were run with my 2500K overclocked to 4500mhz @ 1.325v with one 580GTX at 23c ambient.
The 4 core temperatures were averaged together for one total score, and was run on WinXP 32bit.

Air Cooling;
Noctua NH-D14, Idle = 32.75c, Load = 54.75c
Thermalright 120 Extreme 2 fans in push/pull, Idle = 32c, Load = 51.75c

Standard Water Cooling Closed Loop;
XSPC Rasa RS240 kit, Idle = 30.75c, Load = 50c
XSPC Rasa with a Black Ice 240 Radiator, Idle = 30.25c, Load = 48.75c

Tests below run with a 2700K with hyper threading disabled, which comparatively temperature wise is equal to a 2500K, all the other test parameters are the same and conducted on the same motherboard.

TEC/Peltier Water Cooling
Water Temp. is 12c which is also, 12c below ambient room temperature, (zero condensation), Idle = 14c, Load = 31.25c
Water Temp. is 9c which is, 15c below ambient room temperature, (zero condensation), Idle = 12c, Load = 28.5c

2700K @ 4500mhz Win7 64bit, Intel Burn Test

Peltier information:

The peltier is a simple device, you run electricity through it and the reaction between the two dissimilar metals results in one side getting hot and the other side getting cold, if you do not cool the hot side it gets too hot, overheats, and burns up, simple as that. The Peltiers thermal output can be harnessed and used and in this case the cold side is being used to cool a computer CPU.

The peltier is essentially a miniature freezer/heater with no moving parts to break down, the key is discovering how to use what it can do, to your advantage. Presently the hot side exhaust is being used to heat my office and in the winter it does a very good job of it.

When the CPU (overclocking), cooling community first put the peltier into operation it was directly on the CPU usually water cooling the hot side, which brought unpleasant side effects requiring motherboard insulation to keep from shorting out components from the ice forming around and on the backside of the motherboard socket.

Ice occurs when the surface temperature is cold enough to freeze the moisture in the air, the more humidity in the air the worse it would be.

Comparatively those earlier CPU peltiers were only a small percentage of the size of the peltier I am using in this project, a Potted Peltier, measuring 50mm x 50mm x 3.10mm, wattage = 226w ~ 245w, amperage = 26a max, voltage = 12vdc ~ 15.4vdc, with a maximum hot side operating temperature of 125c or 257f.

The peltiers hot side limit is non negotiable if it reaches 125c it will burn out, so you never want to even get close to that kind of temperature or loose the peltier period, each peltiers operating specs are different and you need to know what the one you choose is rated at.

Another important specification is the Delta Tmax: mine is >68 (C), each peltier is different in it's capabilities just the same as each CPU even the same brand and lot# overclocks differently, because of microscopic manufacturing differences, what I'm saying is a peltiers response is not cut in stone.

To simplify the 68c Delta Tmax, is the ratio of operation between the hot and cold side the cooling sweet spot you're after has to fall in that range of operation to chill the water cool enough to be stored in the insulated reservoir and used.

So if you allow the hot side to reach 154.4f or 68c you technically have a cold side available of 0c, now that's great if you were directly mounting the peltier to the CPUs heat spreader, but not if you are transferring the cold through a 3mm copper plate on the base of the water block.

To store the cold you have to have the cold available, if there was nothing on the cold side of the peltier it frosts over almost immediately once it is powered, when a copper plat is added it takes longer to conduct the cold through the copper plate, the thicker the copper plate is the longer the cold transfer.

Now if you can grasp what I'm telling you here adding the copper plate (Base of your CPU water block), to the cold side affects the peltiers end result in time to cold transfer, which you have to manipulate to get what you need from it.

Remember the cold you store in the reservoir has to be able to counter the heat produced by the CPU, or else the CPU heat load will warm the reservoirs water and become undependable.

That said a hot side temperature of 120f or 49c taking the 68c delta Tmax: into consideration is plus or minus -19c directly on the peltier, but transferring through the copper water block does not drop that low but does yield temperatures cold enough to store in the insulated reservoir to overcome the CPUs heat load.

There are many variables that can affect the peltiers operation and that you can manipulate and adjust to reach your specific goals, like supplied voltage, cooling capabilities of the heat pipe cooler in relation to the fan speed, even ambient room temperature can affect a balanced setup once it's tuned into your needs.

Note: Potted means insulated, some peltiers are not insulated at all and really are not suitable for this type of cooling, you would want to acquire a potted peltier.

It would have been nice to have received some kind of instructions with the peltier, at least which side produced hot and which side cold, I had to use a 1.5v battery to determine that, I guess they figure if you buy something like this in the first place, you should be smart enough to figure out how to use it, anyway still, instructions would have been nice.

When energized this peltier and power supply pulls 277w by itself, so whatever total load you are running this is an added load the entire time it's energized. Depending on the voltage the load temperature of the peltier, (and load temperature is when voltage is applied period!), and it varies from spec'd model to spec'd model.

Logically it would seem the best solution would be to keep the hot side as cold as possible, but that's not the case, you have to allow the hot side to get hot for the cold side to get cold, but since we're only talking a approximately 1/8th inch thick plating, that's a very close distance to play the hot/cold balancing act.

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.

Simple discovery the hot side can override the cold sides effectiveness but news flash the opposite can also happen, the cold side getting too cold, can override the hot sides effectiveness,

So you're after a balancing act of hot and cold to get what you're after, the true key to this things performance is give it the heat range it operates best within or sweetspot, and it will give you the results you're looking for. 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.
 
The TEC Assembly consists of the Peltier module sandwiched between the heat pipe cooler with a cold plate to reach the full coverage of the Peltiers hot surface and the water block that picks up the cold from the peltiers cold side.

CPUpeltier3.png


Close Up

GPUpeltier4.png


Power Supply Information:

A single 12v rail is the best PC available 12v output power supply to use to power a peltiers constant load, make sure it has the raw amperage handling capability, well on the plus side. With a PC capable P/S 12v, you will need to get power from 14g main wires, like from the 8pin or 4pin motherboard connector, those are usually 14g.

Danger: Do not use the 18g 4 pin molex connectors as they cannot handle the load, they will burn up and take the power supply out, and more than likely anything else hooked to it. Additionally do not compromise this power supply selection, to be on the safe side you need amperage capability higher than the peltiers load.

When it comes to powering a peltier you have to get your power from an output area of the power supply that can handle the amperage load. I used 2 yellow positive 14g wires from the 8pin motherboard connection line soldered together, as the positive primary, and 2 black 14g negative wires soldered together as the negative secondary to power mine.

You do not have to use a power supply readily PC available you can find online specific voltage/amperage rated models that will be specifically what your peltier requires, the challenge with those is getting them to power when the PC powers up or down.

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The power supply in the TECBOX is jumpered to the power supply in the main computer, when the main computer is Started Up or Shut Down the TECBOX power supply does the same.

Cooling the Hot Side:

Cooling the hot side of the TEC is a challenge in itself, seeing as how it's best performance comes from allowing the hot side to get hot, however the maximum heat range for my TEC is 125c which is 257f, way past the temperature to boil water. I originally thought water cooling the hot side of the peltier was a good idea since in it’s earlier days it was water cooled but much smaller peltiers were being used, nowhere near these capabilities.

In my attempt to water cool the hot side, the radiator got so hot I couldn't put my hand on it, the XSPC water pump got so hot I burnt my finger on the metal output spout. At that point the peltiers hot side temperature reading on the outside was 160f, I estimate about 180f in the center of the peltier, cooling that much heat is serious and in itself takes a serious dependable and capable solution.

With water cooling the hot side of this higher amperage peltier off the possibility table I turned to heat pipe air coolers, the first was a shelved Tuniq Tower (the original model), with only 3 heat pipes, it just could not overcome the heat the CPU was adding to the water.

I had a Thermalright Ultra 120 Extreme on the shelf and used it to cool the hot side of the peltier, it has 6 heat pipes and is very effective at handling the heat produced by the peltier, also an old Xigmatek S1283 HDT cooler works very well.

Experimented with multiple combinations of fans in push/pull configuration and settled on 110cfm Sanyo Denki San Ace 120mm fans on a Sunbeam fan controller, they give the best of both worlds, they're set low speed presently you can barely hear them but when needed they can crank.

A good heat pipe air cooler can and will cool the hot side, however my choice reasoning was to choose coolers that could still handle the heat load if the cooling fans completely failed. A heat pipe cooler that is on the cooling performance level of the TRUE (Thermalright Ultra Extreme), or the Noctua NH-D14, is sufficient remember the TEC will burn up if it is allowed to get too HOT.

I know some of you would want to take the cheaper route cooling the hot side if possible and since I have directly tested and presently running the Xigmatek S1283 HDT cooler, you should be able to get away as cheap as a Cooler Master Hyper 212 plus or EVO, but no less cooling capability than those.

I also experimented with traditional finned solid copper heat sinks in the server grade to cool the hot side, to see if they could do the job and they failed miserably, so you'll need a good heat pipe air cooler to cool the hot side.

CPUpeltier1.png


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Water Block for Cold Side:

Todays water blocks like the RASA are very flow restrictive, the dispersion nozzle is right down on the base plate pins, it's designed to drop it's cooled water directly on the hot base plate forcing it through the dispersing pins.
A water block is designed completely opposite of what I needed it to do, it is designed to pinpoint cooling to the CPU die location, I needed it to gather cool from the entire copper base contact area, as it was exactly the same size as the peltier.

The cold side of the peltier can produce - 0c temperatures, that's not a time for a block that seems to love getting fouled easily and dropping the flow rate, to allow the water to stay in the block too long without flowing, or it will freeze the water block and split it wide open.

I modified the RASA water inlet injection protrusion inside the top of the block and shaved an 1/8th of an inch off the depth, and also cut diversion channels in it to quickly disperse the water to the entire base plate, transferring the cold from the baseplate which contacts the cold side of the peltier to the water, and forcing it out the outlet.

This water block modification made it very effective in picking up the cold from the peltier transferring the cold to the base plate.

The Thermalright (TRUE), is running a Swiftech Apogee XT rev2, and the Xigmatek running an XSPC Rasa, both water blocks have been flow rate modified.

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Insulated Reservoir:

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After many trial and error experiments I settled on an insulated reservoir I made from 4" PVC schedule 40 pipe, insulated with aluminum faced foam duct seal, as the best solution to arrive at the proper balance of water mass vs peltier cooling capabilities. From the beginnings of this testing (Referenced in the Below Ambient Thread), using a 54qt 13.5 gallon down to the present ½ gallon or 2 litre capacity. Using a lower volume of water reducing the thermal mass, allows faster cooling transfer to the water.

The insulated reservoir becomes a cold water storage tank which becomes the buffer the TEC cooling needs, allowing the peltier/TEC assembly to counter, and lower, the heat generated by the overclocked CPU. Additionally all the tubing runs are insulated to retain as little cold loss to the ambient room temperature and heated operational elements inside the machine.

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Performance Variables :

Water Flow Rate :

Water flow rate affects the cold conduction of the peltier to the water flowing through the water block, too fast and the water does not get cold fast enough, too slow and the block can freeze, presently set on level 2 of 5 settings using a Swiftech MCP655 pump. Flow rate is also a consideration when balancing out the system, regarding taking into consideration the CPUs water block flow restriction. The perfect balance is having the peltier water block able to completely counter the heat the CPU is adding to the water.)

Peltier clamping pressure:

I started with about approximately 25psi ~ 35psi estimated which is basically a standard heat sink clamping pressure, then increased to approximately 50psi+ then after discovering on the net even higher pressure was needed, increased to approximately 100psi.

I'm saying approximately 100psi because I have no actual way to gauge the actual pressure it is wrench tight though, way past any spring clamping.

Addressing Condensation :

Where you live has everything to do with at what water temperature condensation begins to form on the CPU water block, regarding relative humidity, and dew point. Where I live condensation begins forming as a frosty look at 8c water temperature which is 15c below ambient and 16c ~ 18c below the best water cooling radiator loops and as long as I stay above an 8c water temperature condensation is a non issue.

I have an AC unit in my office, that tends to keep humidity levels down quite a bit and allows lower non-condensation freedom. Additionally you can use positioned cooling fans to evaporate the condensation if you need to go lower but by the time you drop down to about the 3c range of water temperature the condensation builds too fast even for fan drying. The fans can actually blow drops of water from the block, and of course that is bad!

Juggling the Hot and Cold:

The cooler/reservoir also allows running the TEC at a cooler hot side operating temperature, and that is controlled by the fan speed on the heat pipe cooler, I know that sounds weird, none the less it's 100% true. Getting what you want from the TEC is a balancing act, you have to let the hot side get hot, for the cold side to get cold.

That is a testament as to how good the Thermalright TRUE actually is, that it can make such a cooling difference and control the hot side temperature with no voltage adjustment to the TEC just controlling the fan speed air flow.

Radiators and Peltiers in the Same Loop:

Many had suggested that would be a good idea which turned out to be a bad idea, the bottom line is the radiator raises the temperature of the chilled water, why go to the trouble and expense to chill the water then allow a radiator to undo it. It seemed like a good idea at first, the radiator could add some stabilization to the loop when actually, it did quite the opposite.

So been there done that, with that idea, and if you're thinking it at this point, forget it.

There's no need to go into any in depth explanation of the whys and wherefores, it is just counter productive to a chilled water cooling period!
 
I'm waiting on a new Tec plate, http://ar.aliexpress.com/item/TEC1-12710-TEC-Thermoelectric-Cooler-Peltier-154W-10A-40mm/653883137.html
The Oem plate is 48w so I'm upping the power somewhat even though this ones rated for 15v, I don't have any holidays until the end of march so plenty of time to play with it and see what the effects are before I strip the beast down and,
Separate the loops!
Gfx will be on the radbox and Cpu will be chillbox cooled and this means a complete rethink of routing and a full rebuild requiring several nights off work 😛
I've also got some MX4 for pasting duties.

@Ryan
**because it's not actually completed yet**
What project ever is finished mate? :)
Moto
 
Lol no, thats just a link for the Tec, I Cba going back onto Egay to link the purchase page, I only bought one tec plate I promise 🙂
Although fifty should cool Nates chair pretty well at the same time as cooking his dinner...
Moto
 
Wait, from what I'm reading, it sounds like you put both peltiers on one loop to cool the res? Seems like it would be more efficient in terms of cooling if you put them both on separate loops to cool the res. If I misunderstood your last few posts, what exactly are you doing? By the way, I read your whole thread and it's really interesting. Good luck with whatever you try next :)
 
Both TEC assemblies are on the CPU loop to 1 reservoir, one TEC assembly is energized when the computer is energized, the other is switch controlled for when I need to go below a 15c water temperature range.
 
I've been thinking this for a while now, and I (think) came up with a solution for replacing insulators for phase changer/freon compressor.
This solution will only work if mineral oil doesn't permeate trough the copper tubes.

The basic idea is to submerge the pc in mineral oil. Since mineral oil is an excellent insulator, you don't need to worry about water condensing on the motherboard. If you have a large enough fish tank, you can create 2 sections. One section to isolate oil (to put compressor, dvd rom, HDD, and maybe a condenser), and the other section for submerging the actual computer.

I'll include a crappy ms paint diagram to show my plan.

http://i47.tinypic.com/15ebor9.jpg
 


This is a below ambient thread!
 


freezing (0°C) is below ambient (19-25°C) 😗

 


How do you plan on arriving at those temperatures with oil submersion?

Oil submersion seems like a great idea to a lot of people have you fully investigated the negatives of doing it?

Remember the colder the oil the harder to pump it and you will have to circulate it.
 


agreed
 


When I referenced water cooling my computer in a conversation with my wife's cousins husband, he actually thought that's what I meant, and I am not joking!

He was completely clueless of water cooling a computer, of even the concept of doing it.

This was the first time I had ever met this guy!

He was on the tongue step of calling me a BS liar!

I looked at my wife and she was, 😱 and she quickly jumped into the conversation and assured him I was telling 100% truth, because if there is anyone on the face of this planet that has seen my temper in action.

It's my wife!

Later he apologized and asked how I kept the parts dry? :) :pfff:

I looked at him and said, "I'm not going there with you on this subject." :fou: :non:

But he was serious and completely baffled regarding water cooling an electrical device, of any kind???

So I said, "The car you drove here is water cooled, isn't it?"

Well yes.

So is water flowing all up under your hood, or is it contained in a circulating system.

Same thing, different cooling purposes. 😗

You have a computer, look it up on Google!

Conversations between him and I were a little on the touchy side, for the remainder of the weekend!

He is one of my wife's family relatives I actually like!




 
The best is looking at stuff in Best Buy or at Microcenter and when asked about watercooling, they always assume it's a Corsair closed loop cooler. I refuse to tell people at the hardware or plumbing store what I'm actually looking for because they struggle to put a PC into any environment that would possibly lead me to their stores...which leads to some very strange looks and interesting conversations.

It's really sad that 99% of the population wouldn't really stop to think about liquids inside a computer...and of those 1%, better than half truly believe that closed loop coolers and watercooling loops are a 1:1 in terms of language and performance.
 


Sigh... I'm only using oil to prevent water from cumulating which is a result of condensation.

I'm using freon compressor to cool the pc. IF you ever used phase cooler, TEC or freon/ r134a to cool the system, you have to do these (pics below) to prevent water condensing!!!

Insulating pins
http://i45.tinypic.com/20jqljr.jpg
Insulation mixture
http://i49.tinypic.com/2z9fw5h.jpg

http://i49.tinypic.com/35avnld.jpg

homemade freon cooler(LOOK AT THE TEMPS)
http://i45.tinypic.com/jtt7bo.jpg

final insulation around waterblock
http://i50.tinypic.com/vrg1lw.jpg

Pics are by dumyyyyyy
 


Please, before you post something like that, try considering these following statements:

Have I ever cooled a pc below 0 degree celcius?

if yes, proceed to the next
if no, you have no right to say something dumb as this


Have I had water dripping near sub-ambient surfaces?
Oh gee, i wonder why!

Your question:Hmm.. i wonder why the water is dripping from the surfaces of evaporation chamber?
My answer:Wow, i guess you never took basic chemistry class in high school
Mate, learn to google-fu :sol:
http://answers.yahoo.com/question/index?qid=20080205201149AAyctKj
 


So true!

If I'm in a hardware store looking for something that I have no intentions of using for what it was actually designed to be used for some sales rep will always walk up trying to be helpful. :pfff:

"May I help you?, What are you looking for?"

A 1/2 ID Barbed Y either nylon or brass

"What will it be used for?"

I know they're just being polite but, Why Ask That Question?

Will it miraculously change the molecular structure of what I asked for, NO!

They ask because they're only trained to help in part associations to the whole.

It's like they're brains pause and refuse to help, even themselves, until it can be associated to some solid object like a sink, garbage disposal, dish washer, washing machine, etc..

"OK I'm water cooling a computer"

Then they go :pt1cable: :heink: That does not compute!

Usually while they're trying to figure out if I'm pulling their leg, I find what I'm looking for and leave, without their help, even though both the brass and nylon Y were there hanging on the display.

If I'm looking for something I intend to use for something other than what it was purposed designed for that's when I love for there to be no floor representative in sight! :)






 
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