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There 90W TEC's if my memory serves me. And theres 5 of them.Quote:
Originally Posted by Uncle Jimbo
The block is uber free flowing. Placed right along with DD MPC Universal.
Nol is doing all the testing needed. :T Thats why he has it. After he figures out the best way to use it, thats how i will adopt it.
Gotta switch setup, hopefully have time today but def will have testing done by this weekend I hope.
Hey nol when you get some numbers out, can you make a new thread so we dont need to go searching for it?
:rofl: thanks NaeKuhQuote:
Originally Posted by NaeKuh
Call it the backup band thread.
Hmmm, working with some of my thermocouples here, and I have to say, I think the setup is a proof of concept, however it needs to be over a larger dissipation area, moving a few hundred watts of energy across something this "small" still makes a rather hot hot side.
nol your telling me a MCR320 with a D5 isnt enough to cool the hotside?
Its not the radiator, its getting the heat out of the pelts and hotside of the block more so. Spreading out the load over 12 pelts would be much easier per say ;)
I see what you mean, running some quick estimates Id say the water block has a surface area for heat transfer of around 480cm^2. Its a nice block design, but that's not a huge number.
For reference, the Coolit products have a hot side surface area of 565cm^2 (except the Boreas which I think doubles this).
Also you may get some losses from laminar flow but I don't think that's a major problem in that design.
You cant compare my unit with the coolit's. My hotside is watercooled, coolit's is aircooled. Theres a difference. Also coolit's uses ALU. That company name is taboo on XS.Quote:
Originally Posted by Scarlet Infidel
So nol you think i should drop 12 little TECs on that instead? :rofl:
You mind trying it out? How the hell are you going to even fit 12 little TEC's.
Would need a bigger plate setup sadly, the idea is to dissipate the heat over a larger surface area, and with smaller TEC's to dolocalize heat.
Sorry, i meant that their cold side surface area was that. It was purely for reference to give the numbers some meaning.
That's kind of my point. If their products are so lousy, you should be trying to beat their specifications.Quote:
Originally Posted by NaeKuh
I did something similar with 6x50W Qcmax Pelts sandwiched between a Koolance HDD block and rack mount radiator, it held ~19C chilling RAM (OCZ Flex), NB & SB (P5K).Quote:
Originally Posted by Scarlet Infidel
Well I stand corrected on getting more heat transfer than heat in. I took a small foam cooler case and mounted the TEC (a 12730) between 2 melcor sinks in the top so that the cold side sink was in the water almost to the TEC, and the hot side was in air. I used a 110CFM fan on the hot side, giving me .06C/W thermal resistance. With 1 gallon of water initially at 25C and room ambient at 25C, I applied 5.1V from a 500W Ultra supply. Current draw settled at 5.8A after a few minutes. That represents 29.6 watts in.Quote:
Originally Posted by NaeKuh
After 15 minutes, the hot side measured inside the sink by the TEC was 30.1C, and the water was at 22.7C. So pulling 2.3C out of a gallon of water in 15 minutes, with a differential of about 7 degrees. That represents about 40W transfer. The total hot side load of about 70W squares with the 5.1 rise pretty well, so I believe the numbers.
That is a single 62mm TEC, and with a different mounting arrangement I could probably get 4 of them under that Melcor sink, but the hot side would get a lot hotter with a 280W load. The TEC would be more efficient at the higher temp but also working across a bigger differential.
Just to see where it would go, I put 12.2V across the TEC and ran the same test. Current stabilized at 22A for a total heat in of about 270W. After 10 minutes, the hot side was at 50C, and the cold side just under 20C, representing about 130W transfer across a 30C differential.
That leads me to believe that 4 of these, run at 5V, would cool a 1GPM flow by .5C and require 120W to do it. That is clearly in the same league as phase change cooling for efficiency.
I'd like to try the same thing with WC on the hot side to see what it would do with a lower differential - my guess is it would move over 50W but use more current, so it might not be as efficient.
Glad to see the theory working in practice. Thanks for trying that out, I hope that as more people see this effect and start believing it the more people will come up with innovative ways to exploit it.Quote:
Originally Posted by Uncle Jimbo
I'm still itching to finish my chiller, but I'm so indescribably busy that there's no way I can spare a weekend to return home to do it.
Edit: also, I must try to spend a little time working on my peltier calculator program, it seemed to be giving startlingly accurate results with a few tests I ran.
nobody has any pictures./////
I have 5 90W TEC's and nol is saying he's having a hard time pulling the heat off the hotside. :\Quote:
Originally Posted by Uncle Jimbo
What you described above was also my theory, use them downvolted nicely, and try to pull the most efficiency out of it. :T
Sorry mate, cam trouble and not alot of time, moving setup most likely a bit later to series as original intended :)
There has been some discussion here on different TEC products. For the most part, the product number is the number of elements, then the max amps i.e. NNNAA so a 12730 is 127 elements, 30 A max. Different doping of the elements and different geometries will produce slightly different performance.Quote:
Originally Posted by Scarlet Infidel
For Bismuth telluride, the most common materials, each element has a nominal voltage of about .123 at 25C max. So TECs with 127 elements have nominal voltage of about 16V at 25C. The current capacity is determined by the size of each element and the voltage by total number of elements.
Peltier elements have a negative coefficient of resistance, which means the effective series resistance increases with heat. That means more voltage is needed to achieve the same current as the hot side gets hotter, or conversely, that lower current will result from the same voltage. Larger elements have a lower nominal resistance. The effective resistance (R=V/I in a running system) varies with both heat and heat transfer and is typically about twice the nominal resistance with a variance of 20% or more over the range of operation.
The heat transfer is determined by the amps and the temp differential. For a given amperage, the lower the differential, the more heat is transferred. Higher currents move the whole curve, so a larger differential can be sustained, or more heat can be moved for a given differential.
You should never exceed the max current for a TEC. High voltages can also destroy the elements. Because different formulations have different resistance, the voltage needed to sustain current varies somewhat, TEC by TEC, in addition to the hot side temp. 127 element units are designed for a max voltage of around 16V at 25C, which is about 18V at 50C. Some TECs have a design point at 75C or 100C or even 200C instead of 25C or 50C - the elements are the same, but higher temp solder is used to allow the higher operating points.
As my recent tests show, the heat transfer is pretty linear with amps down to some pretty low values, so with a low differential and low voltage you can achieve good efficiency but need a lot of big elements to move the total heat load. The conclusion is that for best efficiency use the biggest elements you can get, as indicated by amp capacity, and run low in the curve. I was looking at an 03140 - 31 elements, 40A max, and 3.5V nominal. They have bigger elements than the 12730, and therefore should move more heat. 4 of them in series would effectively be a 12440. I would expect that to have about 30% better heat capability than a single 12730 at the same voltage.
Some good info, seems to match with what Ive got in the way of equations but its nicer to have it in words.
That peltier you mentioned (03140) seems a little obscure. Do you know where to get them from?
When I chose the peltiers I did (TEC12709) I was aiming for:
Highest current,
Smallest physical size (40mm - this was to minimise copper cold plate costs),
Being dirt cheap ($35 for 10 inc. world-wide postage, packaging and paypal fees).
I don't think those TECs are cheap - oddball voltage is usually pretty high price. One example is 03111-5M31-40CQ at http://customthermoelectric.com/tecs...FRaQggodl1GdFA - That is a 03140 part for about $50, but for what you are doing, they are probably not a good choice. I was only looking at them to test the edge case for better efficiency.Quote:
Originally Posted by Scarlet Infidel
The 12709s are 40mm, right? If your setup can take a 62mm, your low cost choice is a 12730 which is the highest current 127 element I have seen commonly available. I have also used the '437W' TEC from Frozencpu http://www.frozencpu.com/products/24...x_Peltier.html which is a 19933, also in a 62mm size. At $50 it is pretty expensive and undervolt performance is only a little better than the 12730.
The biggest amp unit I have seen is a 03178, one example is at http://www.inbthermoelectric.com/highperformance.html listed as inb 31-5.0-1.5 - that is a 55mm unit which can pass 78A. It is a little less efficient at full power than the 12730. I have not used it, but the data suggest 4 of those in series would move 750W at full power (1200W in!). But at 5V across 4 in series, it should move 140W or so with maybe 65W in. That might be interesting to check out the question is what it would draw at 5V, given that is only 1.25V per module.
Good Gawd, y'all!!!Quote:
Originally Posted by Uncle Jimbo
doubles as a large room space heater for those frosty mornings!Quote:
Originally Posted by Clue69Less
guys some update.
Nol took my concept wrong. LOL
He linked the hotside and coldside in one loop. Personally i dont see how he got any gains from this method as its using something simular as a perpetual pendulium. :rofl:
Anyhow Nol finally understood what i ment, and he's gonna have to reloop it as well as bring out another pump.
Nol you must of gone though hell, and probably wondered wtf i was thinkn. :rofl:
No! Thats a possible way for it to work as well, some TEC chillers actually have that ;) If the flow rates just right (often low) the radiator can remove all the heat from the pelts (+ there load) and the system, however the cooled object will have some gains from the cold flow of liquid (not perpetual motion as you have to keep pumping power in ;))
What the fcuk ??? Looping the hot side to the cool side with TECs means the temps will increase, period.Quote:
Originally Posted by NaeKuh
No, you can create a liquid delta ;)
Its done but normally needs much larger systems, I've gotten cold side down a few degrees actually, seems to help temps when the rad can take the heat ;)
If the goal is to achieve and maintain a low temp at the heat source (CPU, GPU, whatever you are cooling) using circulating water to move the heat, then in a steady state model, the water exiting the heat source will be at about the target temp. If that temp is close to ambient, a rad won't do much for you - all it can do is pull out heat inserted after the load (from the pump etc.) . The rad will also keep the temp from going below ambient - it transfers heat both ways. You probably want something like a car thermostat ahead of the rad - route water around it unless the temp is above ambient, to keep the rad from working against you.Quote:
Originally Posted by n00b 0f l337
That's where a post-rad chiller comes in. In order to maintain ambient or even below ambient at the heat source, you obviously need to have the input cooling water below the desired exit temp. If something close to ambient is desired, then even a degree or so is useful.
Martin's original calculation of 395 watt/seconds for 1.5GPM was actually mathematically correct, and as he later stated, the calculation also needs to take into account heat load. But the calculation went south from there...
If we are looking for max efficiency and are using any of the combinations of TECs I have discussed, we will see about 140W transfer. OC'd CPUs can put out more than that, so maybe a higher design center is needed. We can either sacrifice some efficiency, or go with more TECs. But if your average load is less than the TEC transfer, the water will gradually get colder. You can also maintain temp above a lower limit by running water through the rad - that is more simple than varying the TEC power. Another way to control cooling below the desired level is to use the hot side. If you are using air cooling, slow the fans, if you are using WC, slow the pump or shunt the cooling water. Either way, the TEC hot side gets hotter, the resistance rises, the differential rises, and less heat is transfered out. You can achieve very tight temp control with any of those methods.
It is also fairly easy to control TEC input power directly, for low current loads. Essentially running PCM via a big power MOSFET into a low pass filter so the TEC sees a relatively constant voltage.
If I were designing to cool the big heat loads in a state of the art OC'd system (CPU and GPU), I would expect an average heat load of around 250W and upwards of 400W under heavy load. To match cooling without burning power all the time, we could let the power run up if the system starts to get hot, which means using the PCM control.
Let's say we are using the 4 03178 TECs I described earlier. We run them off the 12V line, but with PCM control around output temp at the load, or at the chiller. At idle, PCM sets the TEC voltage at 5 or 6 volts, you pull 140W out, power use is low (65W or so in addition to the heat load), and you are only burning what you need to maintain temp. If the load dumps in more heat, the TEC ramps up as the PCM duty cycle increases, and with the 600W or so transfer available at 12V, I'm sure you will be able to maintain temp if you can supply the current. But 60A or so is serious power, and the PCM system would need to be big too. You'll be burning some serious power at that point though - around 1000W in - so maybe you clamp the upper end at the 50% point, which I think would be around 300W in and 300W transfer (something like 10V, 30A), and let the rad pick up the slack. Your component temp would go up some, but would still be lower than the rad alone.
Here's what I mean:Quote:
Originally Posted by n00b 0f l337
Run a loop on the cold side and another loop on the hot side. Measure the temps in the cold loop vs. TEC voltage. Now run the loops in series. The temp coming off of the cold side (where one would presumably place the water block) will now be wamer than it was at equal volts across the TEC. Therefoe the temps rose.
That's pretty straightforward. In a closed loop system you are pumping heat in to power the TEC, and feeding that heat, plus the transfer heat, back to the rad in the same stream as the cooling water? No matter how you do that, it's hard to see how you get benefit. It is possible to run both hot side and cold side to the same rad, but that also kind of defeats the purpose, since you are asking the TEC to cool its own self generated heat, with a little help from the rad.Quote:
Originally Posted by Clue69Less
I think the sensible thing is just run separate loops - way easier to tune and control.
Ferrotec has some nice on-line curves and you can adjust to compensate for hot side temperature. I've been looking at their 9506/031/600 B which is 03160 spec.
The coefficient of performance (COP) is the amount of heat pumping divided by the amount of supplied electrical power. Max CoP for this unit at 30C hot side is 3.3, and occurs at 7.5A and .6V for a 10C differential. For only 4.5W in, it moves about 15W, which is mighty fine efficiency (but not much cooling).
That's a 55mm size, at a nice fat 4.85mm height. Efficiency drops pretty fast as current goes up, with the 50% point (CoP of 1) at 37.5A with 2.3V required, which draws 86.25W to move 86.25W.
Going to the 2.5 CoP point (15A 1V) moves 37.5W across a 10C differential at 30C hot side. So 5 of those on a 5V supply draws 75W and moves 180W. Using 5 of these with 12V PCM control and a 200W cooling design center, we draw 90W on average, and can move 450W at 12V with a total power in of about 480W. That would probably do the job for keeping even a big OC system with dual graphics nice and cool, and with good efficiency (most of the time)... but at max cooling, the hot side cooling needs to unload the power in and the power moved, close to 1000W. Need a big pump and big rad to handle that. But if we are willing to let the cold side rad do some of the cooling, which means we have to let the outlet temp rise a few degrees, we might decide to clamp PCM at the 1.5 CoP, which provides 350W of cooling for 230W in, and a total heat load of under 600W at max load. That setup does not seem totally crazy - it would maintain below ambient for all but the highest loads, and even then would only go a few degrees above ambient.
For the totally freeze crazy, with a big enough cold side setup, you could run 2 sets of 4 of these on a 12V supply. If you can keep the hot side at 40C, you can drive the cold side close to 0C while moving 360W. You will need to unload close to 1500W, but hey, formula 1 is about performance, not cost...
The graphs are fun to play with - for this TEC they are at http://www.ferrotec.com/products/the...ail.php?id=119
Just looked at those graphs, quite interesting. Its a shame none of the models they have match the ones I'm using.
What I'm interested in, is the massive spike in COP at around 1/8 of Imax. Though there's a huge disadvantage of running any lower than this magic point.
Also, at this point you'd only be pumping around 10w per element (on the type of element I'm looking at) so perhaps a slightly higher current is better in that respect (though still at the peak).
For the closest element to mine, for 20w movement at dT of 10c it will require 7w of power. This is a COP of 2.85 with a hot side of around 33c with cheap air cooling.
As I have 10 peltier modules, I'm looking at cooling 200w load with 70w power to ambient (of course this is best case, there are all the thermal interfaces etc). This seems to match nicely to my previous calculations and real world tests.
When do you expect to have your coolerheater assembled and tested? I hope you have the time to run a range of conditions to reveal its capabilities.Quote:
Originally Posted by Scarlet Infidel
I expected to have it done by Easter, but that clearly didn't happen.
I'm stuck at University now and have a rush of work before the end of term, then its exam time. luckily I find exams easy, so i might be able to get home for a couple of days during the 'revision time' between exams.
I would like to stress that I have made a lot of compromises on the design so it will not perform amazingly, it is more of a proof of concept which I will try and improve on.
Every castle starts with a single stone.Quote:
Originally Posted by Scarlet Infidel
I think you said you have 12709's - you can take the 12712 curves at http://www.ferrotec.com/products/the...ail.php?id=115 and derate by 25% to get an idea of where you should go. You can do a quick double check looking at 12708 and 12710 curves, you should be right in the middle but unfortunately the nice ferrotec calculator doesn't have those values and the thermal enterprises curves are harder to read.Quote:
Originally Posted by Scarlet Infidel
If your hot side is 35C, you have more options for low voltage. You can't achieve better than 2.0 CoP with a differential over 15C.
If the small sinks you describe are kind of 'OEM Standard' solid aluminum, they probably have .7 to .8 C/W rating. So using your numbers, you would be throwing off 27W per element, and would see around a 20C rise. If the sinks are a little better, like a decent sized copper base aluminum fin, you might get .4 C/W, which gets down to the 10C differential level.
Let's look at the 3.0 and 2.0 CoP points. For your units, the 3.0 point puts you at about 1.8A, which with 10C differential and 35C hot side puts you at about 3.7V per unit, pumping about 20W for 6.6W in. That's similar to what you were thinking. You coulkd do 3 groups of 3 in series off of a 12V supply and hit the voltage pretty well.
If you go to the 2.0 CoP, you need a pretty efficient sink - you can't do that CoP with over 15C differential. You'll need about 2.6A and 5.1V, pumping about 26.5W for 13.25W in. So efficiency starts to roll off but you get more transfer, and you are at a nice standard voltage. You have to unload about 40W per unit. That would raise your hot side to 15C over ambient with a .4 W/C sink.
Taking the 3.0 CoP and using the series power scheme off 12V, 9 units would move 180W with a total heat load of 243W. If that meets your cooling needs (that would drop a 1GPM flow about .6C), you might be fine.
Taking the 2.0 CoP and running off 5V parallel, 10 units would move 265W which is respectable, with a total heat load of 400W. That would drop a 1GPM flow about 1C, and if your heat in is lower than 265W, you should also be able to achieve some nice low temps.
dayam uncle jimbo,
You sure know a ton about TEC's.
Well the original plan was having the hotside and cold side seperated. Never in the design did i plan to have them both on 1 loop.
Originally the cold side was to have a radiator. My idea was to take the coolant as closes to ambient as possible, and then use the TEC's to push me slightly into sub ambient.
Well problem came, radiator is no longer that good thing i was hoping for. The capacity for water to hold that much energy was what screwed my thoery up.
So now its going to be a straight TEC setup, no radiator except hotside. The cold side as i said will be connected to a reservoir, where the water inside will be continuously circulated. The water in the chilled reservoir will then be fed to the system.
Or i can just drop that unit inline on the blocks only and run it solo.
If i was to use a lets say 40mm x 2 radiator, you think this would hurt my performance on the cold side? i dont want to dip too far into sub ambient. I really hate preping things for condensation.
Something like this?
http://www.performance-pcs.com/catal...ducts_id=22275
or even this?
http://www.performance-pcs.com/catal...ducts_id=22597
Since you are sandwiching the TECs between a couple of pretty high performance blocks, you are going to be able to move heat around pretty efficiently. Assuming Martin has given you a clean flat mounting surface, and you use AS ceramique to grease it, you can drive the differential to a very low value with a big enough hot side rad. So the question is how much heat, where do you want to put your operating points?Quote:
Originally Posted by NaeKuh
From Martin's photos it looks like you could put up 3 62mm TECs. If we look at the 12730s we have been fooling with, at 5V they will draw about 6A each, so your total is a 90W load. You will be pulling better than 120W out. Almost any $20 ATX supply will drive the 5V at 90W with no sweat.
You have not talked much about your load, but 120W is not much in today's world. This is a big time chiller and I'm assuming you are planning something fairly big under the hood. With no rad, if the load heat exceeds the TEC transfer, you will run the temps up pretty quickly. Might not be a bad idea to have a small rad in the loop with a bang-bang control at ambient, with maybe a half degree of hysteresis to assure the shunt is on before flow thru the rad is cut off.
Several people have mentioned the '437W TEC' that FrozenCPU has available. That is a 19933 unit. Driving it at 12V with the hot side at 25C puts you at about 15A and a 1.6 CoP, for 180W in, and pumps 280W. And that's just one TEC. Not bad but at these power levels still a lot of juice.
Putting that TEC at 5V puts you way down on the curve - 7A - for a total power in of 35W and a CoP of 3 at 5C differential. That would move 105W. Now you are in a position to control things pretty nicely - with 105W in, you pump 315W. But you are so low on the curve that any differential will basically shut down the TEC, so cold side capacity is important.
But that also gives you a way to control the cold side to the temp you desire - if you only want a few degrees below ambient to minimize condensation, then letting the hot side rise a little will reduce the heat transfer and maintain your desired temp. There are a lot of ways to reduce the cooling - reduce the flow thru the rad with a shunt would be one way. Proportional valves are expensive and a pain to set up, but here a simple solenoid valve would work, if the shunt does not shift all of the coolant. You should be able to set that to maintain whatever cold side temp you want.
By the way, my solution to small amounts of condensation is to direct a fan at the part where condensation would occur - that usually keeps things pretty dry. Since the bottom of the CPU or GPU is going to be few degrees above the cooling face, you shouldn't have to worry about hidden condensation. Just be sure there is enough airflow around the water block to keep drips from forming. That should be decent airflow - I use 70MM CPU fans mounted sideways but anything with good velocity will work.
The Thermochill PA160 has .02 C/W with a 130CFM fan, so with a heat load of 100W or so it will rise 2C. But that's a noisy fan. Going to something a little quieter in the 50-70 CFM range pushes the thermal resistance to .03 or .04, which gives a 4C rise. That's good cooling but about all we can allow running the TECs at that low voltage.
A smaller rad would cost you big time - you would have to go to a higher and less efficient voltage to maintain cooling.
I know I said earlier that running the hot side hot is more efficient - that's important at high voltage and big differential, but works against you at these low voltages. We are all learning on this project...
mmm..
okey all i intend to put on this loop im guessing somewhere between 200-215W max.
Q6600 + Chipset.
I already have a meanwell S320 to power these tec's. Nol has it right now and is probably playing with it on them.
Martin did give it a really nice flat surface, his craftmanship is top notch, if you look at the previous pages, around 3-6 you'll see the WIP.
He made the surface large enough to cover 5x40mm or 4x52mm TEC's my main concern was on the massive power draw, so i wanted to keep the wattage low, and see if i could tweek efficiency.
As for controling the hotside, thats easily done. I guess i can connect both loops to a kaze master and have inline probes for both hotside and cold side.
The controller can also control the fans on the radiator and i could adjust as needed. :\
I have one of the FrozenCPU 427 units - I will test it at 4V to see what it does. If it can move around 80W at that low voltage, you will get your 215W with a little to spare, putting three in series across the MeanWell. Looking at the photo with the ruler in it, it sure looks like you can take a 62mm - that translates to 2.44 inches. I realize that the TEC will be out beyond the finned area, but at these low power levels I don't think that is any handicap as long as it is on the copper. Martin drilled the bolt holes clear through, I think - but again with the low power you are running, I don't see much of an issue even if some small parts of the TEC are over the bolt ends.Quote:
Originally Posted by NaeKuh
If that works it will give you low power for sure - that puts you right at the absolute max efficiency point. But remember these are semiconductors, and so when you get right at the trip points strange things can happen.
I'll let you know what I find out with a simple test. <EDIT> see the note below - I'm a lot happer with 55mm TECs given your geometry.
If you are not happy with the bigger TECs, here's another option - http://ferrotec.com/products/thermal...ail.php?id=114 which is a 33710 unit which is 55mm square. It has a nominal voltage of 46.4, so your 12V MeanWell will put it well down on the curve.
At 12V, it draws 2.6A, so heat in is 31.2W. You are at the 2.3 CoP point with a 10C differential, so it will move 72 watts. You have room for 4, so you could move 288W at a cost of 125W. If you want to start out with 3 units, you would move 216W at a cost of only 94W. If I were you, I would just put in 4 and use some hot side control - that way any power excursions up to 288W are handled, and at lower power transferred, your power in goes down. You are at a much more stable point than with the '437' TEC also, which makes the performance a lot more predictable. You should be able to maintain a few degrees below ambient easily.
If you keep the differential around 5C, you will get even better efficiency - that puts the CoP over 3.
That would be a truly awesome setup, and would revise the thinking of a lot of people about TEC efficiency (me included!)
<EDIT> I discovered that you can plug heatsink performance into the ferrotec calculator so i plugged in the PA160 with 130CFM. At 12V, with .02 C/W cooling, that TEC moves 120W! so 4 of them would pump 480W with 125W in. That is serious cooling.
can you link me to the tec's you recomend.Quote:
Originally Posted by Uncle Jimbo
i'll buy them.
Also i was planning on using a MCR320 for the hotside. :T However i could easily get a 480GTX if needed.
The unit is a Ferrotec High Power Thermoelectric Module - Peltier Cooler Model 9500/337/100 B.Quote:
Originally Posted by NaeKuh
Their power TEC page is http://ferrotec.com/products/thermal.../highPower.php
This unit is at
http://ferrotec.com/products/thermal...ail.php?id=114
They have an inquiry form at http://ferrotec.com/products/thermal.../teInquiry.php
You should be able to figure out where there is a distributor or reseller who can supply you with the parts from those links.
The MCR320 has .02 C/W for flow rates 1.5GMP and above. That is the value I used in my model - it should do fine for the hot side. I think it is also less restrictive than the 480GTX.
Okay, ran into a problem, my other pump is leaking like a civ. Got another pump I could borrow Naekuh? Else I think I'm at end of line :(
Gained 4-5C though at the waterblock by running in a single loop, however rad heat output was much higher of course. And actually temps got better with a res then inline, saying that quantity of liquid would help that situation.
This is exactly what i was guessing too. :DQuote:
Originally Posted by n00b 0f l337
Which is why i wanted to paralell a res where one line goes in a loop just to chiller and back, maybe at a slow flow rate, while the other path is high pressure high head going straight to the cpu.
Do you get my logic nol?
I have a DB-1 i can mail out on monday, i can buy a DDC-3.2 and have John at Jab-tech to mail it to you while i mail you the spare XSPC top i have. Or i can send you another D5 in about 2 weeks as soon as dave mails me my sammy chips.
Take your pick.
Another D5 would be good for testing if you can spare the time.
Parallel res though as I tested though really did not work out, not sure why, probably because you lost your temperature differential at the resevoir.
mmm... i was hoping to keep the res colder then the return on the cpu. :TQuote:
Originally Posted by n00b 0f l337
Dumps the heat back rather directly. Also this system seems to work best with LOW FLOW, vs HIGH FLOW.
In your diagram, the res basically acts as a 'capacitor' - it stores energy and stabilizes the system. If it is insulated, and your TEC capacity is greater than the heat load, you can certainly drive the temp below the CPU return.Quote:
Originally Posted by NaeKuh
I did a quick experiment using a setup like this, but with a dummy heat load.
- 1 gallon res, insulated (a Styrofoam portable cooler)
- heat load variable from 0 to 200W
- 100W to 300W TEC cooling in the second loop
- 1.5 GPM in both loops
1. With no heat load, I ran the TEC loop at 200W. Water temp dropped from 25C to 15C in 15 minutes.
2. I set the heat load to 140W. Res temp continued to drop, but much more slowly, reaching 12C in 15 minutes.
3. I set the heat load to 200W. Temp began to rise very slowly, reaching 13C in 15 minutes. That probably reflected pump heat in.
I did the same test, but with the TEC set at 100W. Results were:
1 - water temp dropped from 25C to 20C in 15 minutes with no load.
2 - with 140W heat load, temp started moving up - reaching 23C in 15 minutes.
3 - ran with no heat load until res was at 15C. Ran 200W heat load. temp rose to 20C in 15 minutes.
So the res acts as I would expect - it dampens the rate of change. For a system where you have relatively short spikes of high power, your dual loop design should maintain the average temp for quite a while.
This also opens up an easy way to control the temp - use a bang-bang controller (such as a standard heating control thermostat and relay) to turn the TEC on and off based on res temp. The latent heat will keep the TEC from cycling quickly, and if the TEC transfer power is more than the heat load, you will maintain your load cooling temps nicely.
I tried that using the setup above, but with an old mercury thermostat mounted on a copper plate with most of the plate in the water. The thermostat controlled an air conditioning relay rated at 60A which I happened to have around. That switched the TEC on and off.
With the TEC at 300W and a 200W heat load, and the thermostat set to 18C (the lowest it could go), I powered up the system. The res got to about 17C in a little over 20 minutes, and the TEC switched off. After about a minute, the water in the res got to 18.5C and the TEC switched on. It stayed on for about 2 minutes, the temp went back to 17 C, and the TEC switched off. I ran it for another 20 minutes or so and the duty cycle was very stable, running 2 minutes on, 1 minute off and maintaining temp between 17 and 18.5C with a 200W load.
NaeKuh, send N0L a camera with the pump.
Jimbo, are you making all these calc's based off of Kryotherm's software, the charts you linked in another thread, or just various math equations? If you somehow find the time, could you run through how you:
1. look up the TEC specs
2. run COP calcs
3. determine the greatest efficiency situation
4. develop an implementation plan
Ie. do an example where you just grab a TEC at random and show how you would calc it. Also, characteristics of TECs that we should look for would be great.
Your knowledge seems quite deep on the matter. If you could explain your methods to the rest of us "lunkheads," perhaps the rest of us could start churning out potential situations where a TEC would make sense peformance and economic-wise. It would be a great service for the TEC community here, abroad, and would be highly appreciated.
Raven -Quote:
Originally Posted by THE JEW (RaVeN)
I have gotten a lot of valuable information from the people on this forum, and it is especially gratifying because people actually try things, and measure well, so even if they don't get the results they are looking for, there is usually enough data to see where they went wrong. If I can give something back, glad to do it.
To understand how to analyze TEC performance, you need to understand which performance curves are important, and how to apply them to your problem. That is true for most semiconductor work - the relationships are non-linear. I like the curves at: http://ferrotec.com/products/thermal.../highPower.php - they let you set the ambient and play with other stuff, and the basic curves are fine at default for most purposes. Clicking on a curve gives you a blow up version.
The larger the current capacity, the larger the TEC elements, and therefore the resulting TEC will usually be bigger. Bigger TECS stress the elements more, because whatever substrate the elements are mounted on will change in size as the TEC heats up (hot side gets bigger, cold side gets smaller) which physically pulls the elements around. That is why it is a good idea to maintain stable temps when operating a TEC.
Start with a couple of basic pieces of information.
1 - the heat transfer capability of a TEC element is determined by the current through it, and the temperature differential. Nothing else. So the trick is to figure out what current you will have, and what differential, at the operating point you want.
2 - TECs are made of individual cells called elements. These are all basically the same - 2 chunks of bismuth telluride, one with P doping and one with N doping. I won't go into the physics - the important thing to understand is that those elements have similar voltage performance curves no matter what size or shape they have. Their ability to pass current, and therefore heat, is mostly determined by size.
3 - Each element has a maximum voltage drop of about .122V at 25C and .138 at 50C - they have a negative temperature coefficient, so it takes more voltage to drive current when they are hotter. I use .125 as a design center for high power modules used near ambient. That low voltage is not practical to supply, so TEC designs employ a number of elements in series to get to a voltage that is available in the real world. A standard nomenclature to describe what is in a TEC package is the number of elements and the current capacity, almost always at 50C. I like to use the simple NNNAA description, where NNN is the number of elements and AA is amps, so a 12730 has 127 elements and a max current of 30 amps. Some vendors use 3 digits for amps (amps times 10) and might call that same TEC a 127-300 or something like that. So 127 element TECs have about 18V max voltage at 50C, 199 elements have about 28V, and so on. There is nothing magic about the number of elements, they are selected to give the right current at standard operating voltages. 127's are for 12V, 199s for 24V for example.
4 - it is important to know the number of elements and max current, because you can use the curves from almost any TEC to determine operating points (OP) if you know those 2 things.
There are 4 basic curves that I like to use - those are:
1 - CoP versus current - basically shows where you will end up for a given OP
2 - Voltage versus current - shows how much voltage you need to achieve current - this changes with temp and dT but is linear
3 - heat pumped versus current
4 - total heat load versus current (sometimes called heat rejected)
Having everything with current as the x axis makes it easy to look things up as you go from chart to chart.
Something I really took to heart after spending time on this forum is that efficiency over 1 (more power moved than power in) can only be achieved if dT is less than 25C. Efficiency over 2 requires dT less than 15C. So to move any significant power, you either burn a lot of power, or you use WC or some other low C/W cooling on the hot side.
So let's look at a problem we want to solve. Let's say we want to move 200W, and we want to use air cooling. We would like to be moderately efficient - say 200W in to move 200W. That says we want a CoP of 1.
We will have a total heat load of 400W and we need dT of 25C or less for CoP of 1. Let's say we want to get the cold side to 10C. That means our heat budget gives us 10C over ambient, which means our cooler has to achieve .05 C/W. That is what a pair of TRUEs will give, just to put it in perspective.
We also need a TEC - or several TECs - that can move 200W at CoP of 1. We will be at 25% of max current to achieve that CoP, which puts us at 15% of Qc max. So we need a combination of TECs that have Qc max of 200 /.15 or about 1400W.
We could use a 337 element 10A module rated at 250W Qc max. 6 of those gives us 1500W. 25% of current is 2.5A, which from the voltage curve at 35C requires 12.2V. A quick double check shows each TEC pumps 33W at that OP. Our CoP is 1.08.
I like that because 12V is handy. If we have access to a TEC like that, we're done. In the real world, we're more likely to have some other, less ideal TECs on hand, but the principles are the same.
If you don't have curves for the TECs you have, you can interpolate from whatever curves are close, but the basic principles are the same. The heat you want to move and the dT you need determines the OP. The efficiency you want determines the percent of max amps you want. Stack the TECs in series or parallel to get to that amperage percent at the total amps you need, given the supply voltage you have.
It sounds easy, but it takes a little practice to get it right.
I commend Uncle Jimbo for his deep knowledge and taking the time to explain things. I still think your posts might seem a little daunting to to some. I may write a guide at some point and then you and anyone else who knows about the area can help improve it.
I found this very useful. Looking at curves are all well and good, but knowing the formulas used to make the curves is a lot more useful. That PDF contains all the essential equations and a lot of useful information and even a case study.
I have been implementing those equations in a computer program to calculate peltier characteristics. I have a few things to clear up, other than that it seems to be going quite well, watch this space.
Very nice and easy to read - Thanks!Quote:
Originally Posted by Scarlet Infidel
One problem area you may find is that you don't know dimensions of the TEC elements. You probably can get those by taking the number of elements and max I and Qc, and working backwards to solve for element geometry...Quote:
Originally Posted by Scarlet Infidel
Thanks for the example! I don't have time to go over it right now (implementing Leica's GPS1200 base stations at the engineering company I work for is taking longer than expected), but I'll brush up on 'em this weekend and see if I can't fire back my own example. I figure if I can work through my own, I'll at least have a half decent handle on it. Happy TECing.
Yes, I was having that problem. If you know enough of the right details you can work backwards to get all the rest, it's not ideal though.Quote:
Originally Posted by Uncle Jimbo
okey i need help building something like this. Or rather would you be willing to build something for me.Quote:
Originally Posted by Uncle Jimbo
PM me a price. :D
Or NOL can you build something like that which has a slot for a 2 prong inline probe?
Wait wha?
what jimbo said.. i want. :DQuote:
Originally Posted by n00b 0f l337
a Thermostat option!
Inline? What does the thermostat look like.
Hey NaeKuh, what ever happened to the blocks martin built for you....? they were very cool.Quote:
Originally Posted by NaeKuh
The TEC block chillers? Still here with me, and on that, got a second pump yet Naekuh?
You can use a regular thermostat and a relay in the cold supply to control TEC power - I tested it and did a write-up somewhere on the forum. I just used an old mercury thermostat as a bang-bang controller. They are pretty slow so the duty cycle is not going to stress the TEC, and with a degree or two as the hysterisis it also won't be thermal cycling the TEC.Quote:
Originally Posted by n00b 0f l337
Quote:
Originally Posted by n00b 0f l337
so what the plan for them, i have been waiting to see sombody try to get them going, it's will be sweet, since they are a one of a kind......
havent pulled it off the current server yet.Quote:
Originally Posted by n00b 0f l337
Dave is lagging on my sossoman chips. :T
NOL, you want me to just send you a DB-1?
I can mail that out today or tomorrow.
I realized i have too many friggin pumps so im not going to buy anymore. Gonna pull the dual alphacool out and throw the RD-30 back in.
Sorry RD-30 > dual DDC-3.2 Even martin agree's.
O okay sounds good :)
mail you out the DB-1 tomorrow.
Sorry Nol, as i said dave is taking his sweet long time mailing out my sossoman chips.
I dont mind the wait, its just holding you back tho. And everyone is getting on your butt now that you have the blocks and i feel bad.
Remember guys NOL is donating his time, hence why im being so patient.
Quote:
Originally Posted by n00b 0f l337
Are they in the wine cellar aging to perfection or what?
Just waiting on the other pump. Naekuh, maybe we should consider getting some large extruded aluminum heat sinks, then break the big unit apart, one water loop and then two air cooled sinks ;)
some nice bonded fin sinks here:Quote:
Originally Posted by n00b 0f l337
http://www.aavidthermalloy.com/produ...standard.shtml
they have some big ones in stock and also custom build, so you could probably get an exact match to the size you need. I assume that is just until you get the pump...
Also trying to get some very large Chinese TECs but it will be a while before I manage that based on first response...:rolleyes:
Did you ever decide on the TECs you want to use? Also did you look at the PWM control at http://www.xtremesystems.org/forums/...0&postcount=12
that would let you run at better efficiency and still give power when needed
uhhh wanna grab them for me and then bill me? :rofl:Quote:
Originally Posted by n00b 0f l337
How much are they each? however i just picked up a 480GTX to keep that hotside COOL. :up:
Blame it on martin. His Fault.
NOL i ended up using the DB-1. I got pissed off at my aircooled GPU's. Your gonna need to wait til the weekend for the D5. I finally got sammy up and running so the other quad should come down.
However im debating on just buying you a pump and having john send it to you.
Anxious to see results... TEC-teaser!
Sounds like they got a good plan it just has a lot of moving parts..
:up:
Any updates on that pump mate?
Or have you looked into big heatsinks yet?
EDIT:
Take a look:
http://cgi.ebay.com/Aluminum-Heat-Si...QQcmdZViewItem
WOW! Nice! Someone should get that sink.Quote:
Originally Posted by n00b 0f l337
NOL im terribly sorry.Quote:
Originally Posted by n00b 0f l337
Ive been under tons of backuped work.
NOL also i think i lost your addy. Can you pm me it again.
I'll mail a pump out this week if it kills me.
Also NOL grab that sink and play with it. I'll give you around a 100 dollar play budget. Meaning do whatever you want under 100 dollars.
hey Naekuh I will take that 100 dollar if nol don't use it all :D
http://cgi.ebay.com/Aluminum-Heat-Si...ayphotohosting
Going with that one me thinks
that is one interesting heatsink, but if your chop it right it should be great.
looking forward to seeing those gems rocking some coolness into your system..
Okay, heatsink ordered :)
I'll breakdown the monster I guess into two halves, see if thats better, then we'll see about more tec's and more powersupply, but I think we'd rather avoid that.
lmao..Quote:
Originally Posted by n00b 0f l337
nol you forget what forum this is?
i doubt your curiosity is gonna leave you at that.
If this was the case you'd be on [H]ardForums. :X
Ah come on! im impatient, i want to see how it performs!
:D
Waiting on dat heatsink to arrive.
Heatsink be here, didn't see the package, must have been here since thursday.
Okay, it's really big. 4" tall is very large for a freakin heatsink. A few fins bent but got em back almost perfectly.
Now to figure a way to get this, somehow, attached to to both the pelt setups....
Any ideas? I'm tempted to just grab a wood board and use some big ass clamps.
A couple of pieces of 3/4" alum channel or "T" stock? Do you have a scrapyard in town? It's a great place to find goodiies like this.
ROFLROFL..Quote:
Originally Posted by n00b 0f l337
nol i held on the pump.
I figured you'd be busy with that sink.
I'll mail you a real pump soon. Im rebuilding persephone. And im gona piss off a lot of people in the WIP.
I am gonna post 1 PIC a day. And each pic will make the people in the work log section drool cuz of the quality of parts.
Heheh.
Blame iany for the idea.
Well I found a fan for it, its a 10" desk fan.... Will work amazingly ;)
I think I'm just going to cut a peice of 3/4" plywood and use that as a clamp board...
Pictures? Results? :confused:
Just finished moving house, setting up the workshop again these next few days, then yes, clamps, wood board, a ten inch desk fan, and we'll see how this fairs out ;)
:rofl:
so you got a new big workbench?!?!?! :rofl:
Nope just setting up the old ones nicer.
Uh oh....
Small problem mate, check your PM's.
Everything seems normal except, the pelts don't seem to be doing anything, but still drawing power...
Any updates? :D
Would be so interested in hearing an update, good or bad. It would help me and probably other people out in the possiblities of TEC chillers for PC use. I am looking at a pretty deep money pit right now to try this and so far looks like people who are more equipped and versed to successfully do this are not having much luck.
Also, what would be a better top material for the cold side of a TEC waterblock, Delrin or copper? Seemingly not much more cost to get copper then delrin for me. For the hot side, I will more then likely do an all copper block and also put fins on the top of the block. For the cold side, I'd imagine any extra attempt at aircooling chilled water will only warm it, so probably best to use delrin for the top?
Anyway, looking forward to some info :yepp:
agreed an update would be useful for me too.Quote:
Originally Posted by Herc130
Pics would be nice to have as well. :)
That seems to be the optimal TEC project: High voltages TECs running at 1/7-1/8 of their rated voltages, working at small temperatures gaps 5-10C degrees across, maximum efficiency is pretty important.Quote:
Originally Posted by Uncle Jimbo
If we want lower temps wouldnt be more efficient to put the TECs in a serial cascade: the first TEC running at a 35C hot-30C cold, then another at 30hot-25C cold an the last at 25C hot-20C cold for example.
The hot side water loop can use an inverse current setup (not sure about the term in english)- the last hot side-which runs at almost ambient temps uses the coolest water coming from the RAD, then moves this mildy hot water to the next stage (+5C degrees) and so on.
At this point of the project i believe that TECs working as a post RAD chiller are a true technical challenge,But the concept is quite interesting:
http://www.xtremesystems.org/FORUMS/...=189043&page=1
Just for consideration: why not plan a post RAD chiller that can run straigh from the 12v or 5v line of the ATX PSU, without adapters (maybe using TEcs in series for optimal operational voltage), in a system that is at or slightly BELOW the total system heat output at idle: instead of running the CPU at sub-zero temps, why not running the entire loop-VGA,mosfets,CPU at 3-4 C degrees below ambient: no condensation problems, no need for special PSUs, no need for a PWM regulator. Sure the temps on full load-OC will be modest, but still better than a classical waterloop, and will be much simplier and cheap to implement, and more important: safer for 24/7 use.
I just accidentally found this.
It seems Cathar did something like this a few years back.
http://forums.overclockers.com.au/sh...&highlight=TEC
http://www.employees.org/~slf/images/tecc1.jpg
http://www.employees.org/~slf/images/tecc2.jpg
http://www.employees.org/~slf/images/tecc3.jpg