Thinking of an auxiliary TEC air-to-water chiller

[SlowSVT]

Here is a TEC I'm looking at (I'm getting 2):

http://www.tetech.com/temodules/grap...7-2.0-1.15.pdf

Also I am looking for (2) Thermalright True Copper CPU heat sinks (one for each peltiers). I wouldn't mount such a heavy thing on a mother board but this puppy's is getting mounted to a 5/8" thick homemade copper waterblock.

I will start fabbing the enclosure out of 5052 aluminum (I have a bend brake) and will order the copper plate from McMaster. This thing is gunna add 15-20 lbs to the box when I'm done, will all be internal to the chassis, will package and plumb very nicely. I'm trying to get AutoCAD or SolidWorks to run on this system so I can model the waterblock.

Will post pics as I progress.

[Holst]

Here is a TEC I'm looking at (I'm getting 2):

http://www.tetech.com/temodules/grap...7-2.0-1.15.pdf

Also I am looking for (2) Thermalright True Copper CPU heat sinks (one for each peltiers). I wouldn't mount such a heavy thing on a mother board but this puppy's is getting mounted to a 5/8" thick homemade copper waterblock.

I will start fabbing the enclosure out of 5052 aluminum (I have a bend brake) and will order the copper plate from McMaster. This thing is gunna add 15-20 lbs to the box when I'm done, will all be internal to the chassis, will package and plumb very nicely. I'm trying to get AutoCAD or SolidWorks to run on this system so I can model the waterblock.

Will post pics as I progress.

That PDF is very useful.

If you look at the 30degree potted graph you can see how the hot side temperature affects the amount of heat you can take out of the water.

If you can keep the hot sides cool then the TEC is pretty effective, but once the temperature rises on the hot side the amount of heat removed drops quickly. This is why aircooling TECs is difficult.

You can also see how much waste heat you will have to cool at given temperatures.

You will also see that running the TEC at a lower voltage makes the COP much better, which is why people build large TEC arrays and watercool them for best efficiency.

[SlowSVT]

That PDF is very useful.

If you look at the 30degree potted graph you can see how the hot side temperature affects the amount of heat you can take out of the water.

If you can keep the hot sides cool then the TEC is pretty effective, but once the temperature rises on the hot side the amount of heat removed drops quickly. This is why aircooling TECs is difficult.

You can also see how much waste heat you will have to cool at given temperatures.

You will also see that running the TEC at a lower voltage makes the COP much better, which is why people build large TEC arrays and watercool them for best efficiency.

Holst

I will be limited to (2) 50mm peltiers. I was not aware you can throttle down the voltage on a peltier, is that true?. If that's the case can I go with a 245 Watt unit and trim the voltage as needed?


I think having (2) Thermalright True Copper CPU cooler will be my best bet with regard to shedding the heat in the available space I have in the chassis. I'm up against the amount of radiating surface area I can cram in that pass-thru channel. I looked to see if any graphs were available for the heat sink but so far no avail.

http://www.thermalright.com/new_a_pa..._t_copper.html


Here are photos of the mock-up.

[Holst]

To get the best efficiency you can drop the voltage.
This is one reason to buy an external adjustable PSU as you can tune the voltage to keep the hot side temperatures in the right range.
If the heatsinks cant keep the hot side temperature down you wont get very good results.

With an adjustable PSU you could run larger higher wattage peltiers, but if you are powering from the PC PSU then you need to pick the correct size peltiers for your given voltage/cooling which is quite difficult to do.

The mockup box looks pretty good as your exhausting the hot air from the case. (Although it looks like you have one fan the wrong way round)

[SlowSVT]

To get the best efficiency you can drop the voltage.
This is one reason to buy an external adjustable PSU as you can tune the voltage to keep the hot side temperatures in the right range.
If the heatsinks cant keep the hot side temperature down you wont get very good results.

With an adjustable PSU you could run larger higher wattage peltiers, but if you are powering from the PC PSU then you need to pick the correct size peltiers for your given voltage/cooling which is quite difficult to do.

The mockup box looks pretty good as your exhausting the hot air from the case. (Although it looks like you have one fan the wrong way round)

That makes sense. Do you know of a PSU with a single 12V output that has an adjustable output and a small form factor you could recommend? Then I gotta figure out where to put it. Using a potentiometer to adjust the output would be huge and require it’s own peltier

Good "catch" regarding not orientating the exhaust fan in the proper direction. I was wondering if anyone was going to pick-up on that and call me out on that one. I'm gunna be more careful next time

[Holst]

You can buy a meanwell supply that is small enough to fit in a case, but they are not adjustable.

I use a lowe PSU that is 5-15v adjustable and will run upto 40amps, but its too big to fit in a case (unless its a VERY big case)

The best bet to find a PSU is to look on ebay in the CB radio section.

You do have some options if your using a PC power supply. You can run the peltiers in parallel or serial (6v or 12v), you may also be able to use the 5v line to power them.

[Holst]

http://cgi.ebay.co.uk/12-volt-variab...item2a0ddb80ab

This would do the job reasonably well.

http://cgi.ebay.co.uk/Palstar-SPS960...item5d2d665dfb

This is similar to my PSU except that mine has analogue gauges and only cost £50 delivered second hand

[SlowSVT]

You can buy a meanwell supply that is small enough to fit in a case, but they are not adjustable.

I use a lowe PSU that is 5-15v adjustable and will run upto 40amps, but its too big to fit in a case (unless its a VERY big case)

The best bet to find a PSU is to look on ebay in the CB radio section.

You do have some options if your using a PC power supply. You can run the peltiers in parallel or serial (6v or 12v), you may also be able to use the 5v line to power them.

Thanks for the links. For now I decided not to install another PSU. There is room in the bottom but it will block intake airflow and will drag more heat into the chassis. There are plenty of unused taps on the PSU so I have options as you stated. I will talk to peltier mfg tech support and see if we can optimize the TEC to the heat sink. I will get the radiating surface area and will be moving about 180 cfm thru the channel so we can get a rough idea on sizing and voltage requirements.

I'm placing orders tomorrow for the components and will fabicate the enclosure once I have the parts gathered.

[TJ TRICHEESE]

it will be interesting to see how this turns out

[zipdogso]

A lot will depend on the heat dump into the coolant and the efficiency of heat transfer by your copper plates etc BUT if the heat flow throught the TEC is anywhere near its rated value you cannot cool the hotside with a fan.

Undervolting the TEC will help even quite large TECs undervolted can be run air-cooled so long as their Q is below 100w.

The heat coming off the hotside will be the amount of cooling plus the heat generated by the TEC. If you are running the TEC at 12v like I think you are if the heat dumped into the coolant is high and you have efficient heat transfer the amount of heat coming off the hotside can be as high as 2.25 times the cooling power.... so in the case of your 125w (powered at 12v will cool a max in the order of 80-90w) if the TEC draws 90w from your coolant (I very much doubt it will.) the hotside output could be as high as 200w.....any CPU cooler will struggle. Of course the run parameters of a TEC change constantly in use so this wont be a constant scenario.

In general it is not considered a good idea to air cool any TEC larger than 100w Qmax....you will get overheating and it will contribute to the eventual demise of the TEC.

since that PSU has multiple rails, you can run the TECs off one each, one for your gpu and some components, and one for the board and remaining other components.
spreading out the load is important, and its easy to mess that up with TECs pulling so much power by themselves and only one wire (where high end GPUs have multiple connectors and its a little tougher/impossible to have them all on the same rail)

This is the worst advice I have ever seen. TEC's generally draw far too much current for one wire of a PC PSU. The wires in a PC PSU are rated at about 8 amps max, 7 amps for safety even the the small 125w units the OP plans will probably draw 7 amps easily. TECs should NOT generally be run from PC PSU's they are not designed to supply high current devices. Certainly if you do choose to do this you should NEVER run them with one wire you should have one positive and one negative wire for each 7 amps of max draw. So if your TEC draws 9 amps you should use 2 positve wires and two negative wires.

For safetys sake it is always best to use a dedicated supply and leave your PC PSU well alone.

[Manicdan]

This is the worst advice I have ever seen. TEC's generally draw far too much current for one wire of a PC PSU. The wires in a PC PSU are rated at about 8 amps max, 7 amps for safety even the the small 125w units the OP plans will probably draw 7 amps easily. TECs should NOT generally be run from PC PSU's they are not designed to supply high current devices. Certainly if you do choose to do this you should NEVER run them with one wire you should have one positive and one negative wire for each 7 amps of max draw. So if your TEC draws 9 amps you should use 2 positve wires and two negative wires.

For safetys sake it is always best to use a dedicated supply and leave your PC PSU well alone.

open up a PSU and see that all the wires are usually soldered together anyway. i didnt say run one WIRE, i said one RAIL. take a PCIe cable and use all 3 black and all 3 yellow together to reduce the load on the wires. the rail is good for ATLEAST 150w since thats what a PCIe cable pulls, his is good for 18A, which is clearly more than enough

[TJ TRICHEESE]

i wouldn't argue with zip, he knows what he's talking about.

[SlowSVT]

I'm not crazy about the idea of an external PSU to run the peltier and from what I have read on this site is a CPU heat sink is not a good idea due to the fact it won't have the capacity to accept the heat from the peltiers and will need to be under-voted to keep them form incinerating themselves. Holst, this is something you touched on regarding using a heat sink over a peltier. Scrap that idea

So I took a different approach that will give me two options. I got (2) Black Ice Extreme 140 rads instead of the Thermalright True copper heat sink. I will put both of them downwind of the black Ice 360. Both rads will be fed from the reservoir in parallel. The output of one rad will go to the cool the CPU and the other will cool the GPU and the MB chipset.

I vented the hot swap drive bay door and will mounted a corrugated med mesh filter from a Frozen CPU 140mm fan filter to keep the rad from ingesting dust. I wish this screen was available in bulk. This is probably the best filter media available for fans having about twice the filter area of a non-corrugated screen. The air enters from the front and exhaust out both side of the chassis. I will post photos of the exhaust fans as soon as I'm done modifying the side panels.

I have left 1" of room in the back of the fan housing for the hot side of a water-to-water TEC heat exchanger which I would mill from copper plate. I laid the design out in SolidWorks which I can post images of later. The heat exchanger is 8" x 6" which is fairly large so I can fit 8-12 50mm peltiers depending how they are arranged. Right now I don't think the TEC chiller is the way to go for me at this time. Unless someone can convince me this set-up it would be worth doing and that the arrangement will be effective and fairly efficient.

This is packaging real nice Fabbing the fan duct rear cover and fan mounting brackets next. I'll keep you posted.

[SlowSVT]

Todays progress

[Ultrasonic2]

nice alu fab there .

If you make a chiller with 8-12 TEC's it could be incredibly Efficiency and effective IF made and implemented correctly .

[SlowSVT]

Almost done

[Vinas]

open up a PSU and see that all the wires are usually soldered together anyway. i didnt say run one WIRE, i said one RAIL. take a PCIe cable and use all 3 black and all 3 yellow together to reduce the load on the wires. the rail is good for ATLEAST 150w since thats what a PCIe cable pulls, his is good for 18A, which is clearly more than enough

Zip is correct. He was here when I did it years ago. PC POwer & Cooling engineer recommended using the PCIe connector, because it was rated to ~27amps. It's not the stupid connectors at the PSU side, it's the run of the wire and the plug which can and will melt if you just blindly plug into any 12v line.

That said, you can combine two leads from the PCIe connector on the + and - sides. If you must use an ATX PSU, that would be the preferred way to do it. That and remembering not to load up over 80%.

Edit: I can't be bothered to read this whole thread but the OP should think about condensation. it's usually one of the worst enemies of a TEC builder...

[Manicdan]

Zip is correct. He was here when I did it years ago. PC POwer & Cooling engineer recommended using the PCIe connector, because it was rated to ~27amps. It's not the stupid connectors at the PSU side, it's the run of the wire and the plug which can and will melt if you just blindly plug into any 12v line.

That said, you can combine two leads from the PCIe connector on the + and - sides. If you must use an ATX PSU, that would be the preferred way to do it. That and remembering not to load up over 80%.

zip misunderstood me
and you seemed to have said the same thing i did

why does everyone seem to jump in as if ive never played with TECs before? i use to run them off a PSU that still works and is now >7 years old.

[SlowSVT]

Progress as of 3/5/11

Plumbed. There is water flowing thru the circuit. Not one leak or a drop of water anywhere in the system. The Swiftech 655 @ speed setting #3 is barely audible





One rad cools the CPU, the other cools the GPU/MB chipset





The two Bitspower reservoirs are working great. The top res lower RH inlet is the feed from the 360 rad. The opposite side top port (not visible) is the fill port inlet and air escape. The bottom res both lower outlets feed into the lower rads in parallel. Once I'm done bleeding the last few bubbles out you won't be able to tell if the water is circulating. I need to “up” the pull down resistor for the LED's (only the bottom LED's are plugged in). Too bright




I'm installing the lower rad fans next

[SlowSVT]

Added the Delta 190 cfm fans. They should pull the air thru those densely finned thick Black Ice 140 rads.







Didn't take a pic of the RH cover with the fan because I haven't dressed the wires and can't latch it closed at this time.

Next thing is a metal base frame with casters. I want to raise the chassis up off the floor to reduce the air intake restrictions and dust clogging the filters under the chassis. I will also be able to slide it out from under the desk for easier maintenance.

[SlowSVT]

Finished the castered base frame which needs to be powder coated which came out real nice. Just have to complete some minor wiring and my system is done. I've been building this system since December.

As I stated I am going to forgo the TEC cooler for now and see how effective my 3 radiator cooling system works before I decide whether or not I am going to retrofit the TEC water chiller to my system. When my system is done I will post the operating temps here and see if it's worth taking the cooling system to the next level.

I am going to post the complete build in the water cooled section on this site. There are a lot of innovative features on this system which I think people will be interested in seeing.

[Chillerzero]

where is the TEC cooling ?

[SlowSVT]

where is the TEC cooling ?

Haven't added it yet. I want to run the system for a while without it and see how it performs with the 3 rads. The plan is to mill a copper hot & cold water block mounted where the four tubes enters and exits the back of the fan housing I fabbed. Hot side in the fan housing/cold side in the MB compartment. It's a fairly large surface and can run 6 or more TEC. I welded up a caster frame to roll the chassis around and get the intake up off the floor and is where I will mount an external power supply to run the TEC's.

All I'm waiting for to boot the system is the new Micron C-400 SSHD which should be out by the end of the month.

[zipdogso]

If your planning on multiple TEC chiller and your looking at least 6 there are ways of wiring them in series/parallel groups to keep the current draw down but honestly if your planning something like this for stability of the rig you really should use a secondary power supply.