Cooling a Peltier

[lordneo]

Question bout Cooling a Peltier

I was playing with the idea of cutting out a side of my soon to be reservior replacing it with copper plate , using silicon and bolts to keep it together and dry , then attaching a peltier to the copper plate and a heatsink on top of that , all of it being
clamped down by a custom clip bolted to the copper plate.

now what wattage peltier can safely be cooled using a heatsink.
(WIthout the extra heat supplied by a Cpu)
i was thinking of getting Te's 122 watt peltier
(if my 1.4 ghz tbird thats putting out 100+ watts of heat can be cooled via heatsink to 50C then a 122watt would be my Max)
that is 62X62 sixed tec ,thus it will cool more of the plate thus increasing the amount of water that can be cooled.
i dont want to Freeze the water , thus the pump wont pump it.
chill it down say 10 degree's below room temp.
before being pumped to the waterblock.

and im not looking for subzero temps on my proc.


Thanks



:)

[dimmreaper]

Originally posted by lordneo
Question bout Cooling a Peltier
now what wattage peltier can safely be cooled using a heatsink.

That depends largely on the surface area, shape, and material of the heatsink. An aluminum heatsink with 1 square foot of surface area (PEP66 comes close) should handle an 80W pelt (this is just a rough guestimate based one my working knowledge of peltiers and convexion) However a home brewed aluminum heatsink with 3 square feet of surface area might handle as much a 240W pelt (assuming the thermal co-efficient scaled linierly with the surface area, which is somewhat unrealistic).

[cjtune]

No matter what surface area in available on the hot or cold side, and as long as there is actually a deltaT, there will be a net positive heat transfer to the ambient. The size of the reservoir itself might make it more difficult to chill the water as it has more surface area for heat to *come in* from the ambient as well -try and insulate your reservoir and tubing, perhaps?. But to promote as much heat transfer as possible, first make sure that the hot side gets enough convection cooling, ie. use the largest HSF you can get your hands on.... those that are good enough for 1GHz Athlons. When sizing heatsinks for your pelt, you only need to select one that can handle an Athlon of the same wattage, ie. get a HSF for a 80W peltier as you would for a 80W CPU. Also make sure that the cold side gets to transfer as much heat away from the water as possible -maybe you can fit in a smaller pump that serves to circulate the water around the reservoir and solder some simple fins to the copper plates. Stagnant water is bad at circulating heat (or the lack thereof) so the cold water might still be hanging around in the reservoir while the warm water goes to teh waterblock.

[Colin]

Sorry I must not have had enough coffee when I first posted. The people I know that have tried this have had a hard time keeping the heat from the pelt and HSF from warming the reservoir enough to make the pelt useless.

[dimmreaper]

Originally posted by cjtune
When sizing heatsinks for your pelt, you only need to select one that can handle an Athlon of the same wattage, ie. get a HSF for a 80W peltier as you would for a 80W CPU.This could only happen in a perfect world. The Pelt is capable of pumping 80W, but it will also generate much more heat because it too is using large amounts of electricity.

Find the voltage and amperage specs of the peltier. Multiply the two to calculate watts. Add those watts to the peltiers pumping ability (Qmax), and that is how much heat you need to get rid of.

So for example you need a cooling solution capable of removing 450 watts of heat to keep a 172W peltier cool!

A rule of thumb is that the heatsink needs to be able to move about 2.75 times the peltiers Qmax.

[Memphis]

Originally posted by lordneo
Question bout Cooling a Peltier

I was playing with the idea of cutting out a side of my soon to be reservior replacing it with copper plate , using silicon and bolts to keep it together and dry , then attaching a peltier to the copper plate and a heatsink on top of that , all of it being
clamped down by a custom clip bolted to the copper plate.

now what wattage peltier can safely be cooled using a heatsink.
(WIthout the extra heat supplied by a Cpu)
i was thinking of getting Te's 122 watt peltier
(if my 1.4 ghz tbird thats putting out 100+ watts of heat can be cooled via heatsink to 50C then a 122watt would be my Max)
that is 62X62 sixed tec ,thus it will cool more of the plate thus increasing the amount of water that can be cooled.
i dont want to Freeze the water , thus the pump wont pump it.
chill it down say 10 degree's below room temp.
before being pumped to the waterblock.

and im not looking for subzero temps on my proc.


Thanks



:)

Is this Neill from http://forums.overclockers.com.au/forumdisplay.php?s=&forumid=24

My best advice for your peltier/water cooling/fridge compressor/peltier reservoir mod project is to simplify it.

Start off buying quality components like the Eheim pump, DD Maze II block, DD radiator and see how you go. Try silicon hose too. The flexibility makes a big difference in installation.

Once this has been completed successfully, move on to peltier cooling. A 172W peltier with a dedicated ps that will give you at least 18V with sufficient amperage will do you fine. Make sure you seal everthing up with di-electric grease and silicon. Use a neoprene gasket around the peltier and socket area.

If direct peltier cooling becomes a bit too warm and fuzzy for you, try a compressor based refridgeration system.

Once again, start simple and get it working before you look at more complex cooling options.

If this is not Neill, sorry! Its still good advice though. Try contacting Amy from the above link regarding peltier/reservoir cooling. Amy has had a lot of very good experience and loads of pictures!

Cheers