TEC coldplate & paste Questions

[ricecrispi]

I have some spare WCing gear around so I decide to make use of it and TRY to setup a peltier waterchilling setup. I was planning to sandwich 172 watt 40x40mm pelt between two Polarflo TT blocks.

40x40mm size was a big factor. I thought the blocks base would cover the area.....
Did some math and they only cover 38.89x38.89 mm square area on a circluar base. So the corners where the leads enter are not covered.

1)Can I still run them like this or should I get a coldplate? If no.
2) Where can I get a 50x50mm or larger coldplate? I've couldn't find any with a search (decent, but not exhaustive) on google, online cooling retailers, this forum and some other forums. Found 40x40mm. Would I have to get someone to machine it for me.
3) What paste should I use? Is basic white silicon grease good enough for the job? I see alot of ceramique being suggested or used.

[jaydee]

I would try it as is. I was using Radio Shack whilte silicone on my test bench for a long time. I changed to a silver stuff from Dynex and get about 5C cooler temps. I like the Dynex stuff over AS5 for testing as it dosn't need a lot of cure time. The ceramique should be good to.

[Marci]

I always stick to Silver based for hotside and ceramique for cold side... just seemed logical choice when u look at arcticsilver.com and each TIM's operating temps...

Ceramique::> Peak: –150°C to >180°C Long-Term: –150°C to 125°C
Silver5::> Peak: –50°C to >180°C Long-Term: –50°C to 130°C

Used to seem MORE logical back in days of AS3 tho, as think it's lowest was -10 iirc... Only real reason I started using Ceramique was when I regassed the prommi to run at -70. Noticed silver based compounds stopped doin' the job... since then always stuck Ceramique on TEC Coldside and on PhaseChange.

[baron_iv]

If you do decide to go with a hotplate, you could always just order a flat or bar of copper from http://www.onlinemetals.com

They have a great selection of just about any size copper/aluminum you'd need (along with other metals and delrin). The prices are also pretty good. That's where I get my material for the waterblocks I make. Another good thing is that their shipping costs aren't outrageous like some places I've looked at to order metal. I buy a lot of their 2" width 12" length and .5 or 1" depth/height copper. That size is pretty good for making some pretty monsterous water blocks.

Anyway, good luck with your pelt setup, it'll make you very happy.

[ricecrispi]

I sourced some 50mm coldplates for the future. I'm getting two mean well 300-13.5V that can supply 22 amps. They can go from 12 V to 15 V. I can use two pelts to cool directly but I don't want to condensation proof my stuff but I can if i change my mind.

I'm trashing the two heatsinks sandwiching a single 172 watts pelt idea. The pelt has Vmax at 24 volts. I believe I don't have enough to power the pelt but the pelt is too weak anyways when I can have a more powerful and efficient setup.

I rather use two pelts or get a powerful setup

NEW PLANS

I will have the pelt sandwich against waterblocks and a rad. The waterblocks will be cooling the hotsides and cold sides will cool the rad. The rad is sealed with antifreeze/h2o mixture and is being cooled by the cold side. THe rad should be great at absorbing and transfering heat from the loop.

What I need is to find the best pelt setup and some opinions with people with real time experience. I'm just making decisions from what I read.

[ricecrispi]

PLAN ONE
I will have two pelts on both sides of a 50mm wide rad. Two pelts from 12 volts to 15 gives me a lot of flexibilty and efficiency. 180 watts to 280 watts. I like this one the most.

169 watt / 16.4 VMax / 16.1 IMax
5 volts: 15.7 watts; 4.90 amps
6 volts: 22.6 watts; 5.89 amps
7 volts: 30.8 watts; 6.87 amps
8 volts: 40.2 watts; 7.85 amps
9 volts: 50.9 watts; 8.83 amps
10 volts: 62.8 watts; 9.81 amps
11 volts: 76.0 watts; 10.79 amps
12 volts: 90.5 watts; 11.78 amps
13 volts: 106.2 watts; 12.76 amps
14 volts: 123.2 watts; 13.74 amps
15 volts: 141.4 watts; 14.72 amps
16 volts: 160.9 watts; 15.70 amps


PLAN TWO

I might be able to use this pelt at 13.5 volts 178 Watts but I'm am worried about pushing the PS to the edge. I'm trashing the idea in general because i don't think the waterblock can dissipate the amounf of heat of 140 to 170 watts. Can some confirm this

I can use two pelts and get extreme and push the setup to the limits. 340 watts to 280 watts total.

226 watt / 15.2 VMax / 24 IMax
5 volts: 24.5 watts; 7.89 amps
6 volts: 35.2 watts; 9.47 amps
7 volts: 47.9 watts; 11.05 amps
8 volts: 62.6 watts; 12.63 amps
9 volts: 79.2 watts; 14.21 amps
10 volts: 97.8 watts; 15.78 amps
11 volts: 118.4 watts; 17.36 amps
12 volts: 140.9 watts; 18.94 amps
13 volts: 165.3 watts; 20.52 amps
14 volts: 191.7 watts; 22.10 amps
15 volts: 220.1 watts; 23.68 amps

[baron_iv]

To get rid of THAT kind of heat, you're going to need to start looking to multiple and/or larger radiators, or possibly chilled water. By the time you add the heat from the TECs, the heat from the CPU, GPU and possibly the chipset, as well as the pump(s), you're talking a SERIOUS amount of heat that you need to remove to cool effectively. You might want to get a rough estimate (it's better to OVERestimate) of how much heat you're going to have to remove from the water, then post again so that we can have some idea of what to recommend.

[ricecrispi]

amd 64 rev E @ 2.5 ghz ----90 watts max
6600gt--------------------------60 watts not sure Max W but seems correct. I always cool backside aswell.
DFI nf-4 chip-------------------25 watts I have no clue how much?
L35 pump----------------------19 watts.
------------------------------------
200 watts heat from the loop. I would say at all things on range is 170-215 watts.
Cathar was talk about power draw doesn't= heat dissipated due to ineffieciency of the PSU. I say the number is lower but I will find out.

169 Watt pelt at 13.5 V gives 114.7Wx2 pelts= 230 watts of pull.
can always up the voltage up to 15 V if it's not enough power.

13.5 V x 13.25 I = 178.8 x2 = 357.75 watts
357.75 watts + 200 watts from loop + 20watts pumps x2 = 597.75 watts total

Right now I have a bonny 120x2 heatercore and chevelle heater core. Need more Info on HC Dissipation and flow rate charts. I think I can handle the heat load unless my thought process is wrong.

Thats 270 watts for each waterblock. Even though the rads can handle this how much temp differential will I get? (1 TH/Tc) x temp delta. I get the math but whats my temp delta. Can't be -60C or -70C theorectical.

I will add more info and do more research in the future but I'm very noob at this.
look over this and look for some mistakes on my part.

I'll be back in a few hours to add more info

[baron_iv]

Theoretical and actual delta T will be considerably different.
Cathar is very correct (as always), power draw doesn't equal the amount of heat that you need to dissipate. I've found that it's easier if you think of a TEC as a little heat pump. It makes heat...if you can get rid of that heat, THEN you get cooling. When using a TEC for cooling purposes, it's very important to remember that it's going to pump out a massive quantity of heat for a little bit of cold. They're really rather inefficient. However, they are a lot of fun to play with.
However, -60 to -70 temps with a TEC...probably not going to happen with watercooling. When you stick a TEC on top of a CPU or GPU, you not only have to dissipate the heat from the CPU/GPU, but you also have to dissipate the heat from the TEC. I don't know of any waterblocks that can keep up using "standard" watercooling (when I say "keep up" I mean below ambient temps on the CPU). You're going to need to get into the realm of chilled water to get sub-ambient temps.
I usually get between 2-4C below ambient by using an air conditioner to blow into my radiators, sometimes it's right AT ambient. It's really difficult to get rid of a lot of heat.
You've apparently done your homework though, so you should be good to go. One or two TECs can usually be overcome by watercooling as long as they aren't massively overpowered.
Good Luck with your setup.
-baron_iv