Which peltier setup is best for sub0 temp

[captain]

Which peltier setup is best for achieving
-20 degrees.

I will cool the hot side with water and glycol at -11 degrees.

Should I use only one 172 watt peltier or combine 2 172 watt. Will I get lower temperatures if I use one 172watt ontop on one 120watt . Shouldn't I get better performance since I will have cooler "hotside" on the peltier 120watt near the processor.

[mkosem]

hmm, should be good, that should double the deltaT.

--MAtt

[ZULU]

Man you never stake pelts the only way you can use double pelts is to get a large coldplate . And place them beside each other and like a PIII water block and stick it on your socket a

[LiquidCool]

You CAN stack peltiers, provided the one on top can remove the heat from the one on the processor... It's much better to put one 172 on the CPU, then a cold plate on that with 2 172W pelts on it... that would get really low... Your gonna need one hell of a waterblock sitting on those 2 172w pelts though...

I drew up a pic for ya...

http://liquidcool.org/misc/forum_pics/peltier_stack.gif

[cmenaia]

i have to disagre, the loads on the Pelties make the DeltaT smaller, you can achive best results just using 2x172W side by side.
that is easy to see in this example:
cpu watts dissipated 100W
temp hotside=-30ºC(-22ºF)
temp on cold side 2x172W=-78,7ºC(-109,6ºF)
2x172W plus 172W =-72,6ºC(-98,7ºF)
NOTE:in real test the temp. may not be as low as above becouse i simplify the calculations, hope you got the point, staking pelties only work when the loads are small, this is not the case. :eek:

[inda]

besides looking at the watts a pelt can move you should also pay attention to the delta not all places that sell tec give you that info but you can always look it up at tedist. the delta is how far a pelt will lower x ammount of watts under perfect conditions

[LiquidCool]

Actually stacking pelts DOES work. You just have to have enough of them. You can buy stacked pelts from the manufacturers. You have to make absolutely sure the top level pelts can remove the heat of the pelt on the CPU or it will fry real quick.

While the pelts side by side have the capacity to remove more heat, the stacked pelts can produce more of a temperature difference...

[imagex]

in my search for pelts if found that some come as stacked sets. :)

[Kevin]

Yah but they're usually low wattage :(
Originally posted by imagex:
in my search for pelts if found that some come as stacked sets. :)