peltier device advice.

[Akoto]

I'm buying a 40mm 80w peltier device and I have some questions about how to hook it up to my cpu...

1. What is the best way to attach it to my ATX powersupply? It runs on a max 15.2v, but with a max of only 8A. My powersupply sais it supplys 19A per one of the 12v outlets. If I attach it to one of thoes, will it supply the device with only what power it wants, or is it going to try and cram all 19A down its throat and burn it out?

I read one reply on a forum regarding attaching a cpu fan to a 12v outlet, and it suggested that it would be alright, but only if it were plugged into an already used one (like an extention past a harddrive or something). Is there any truth to this?

2. What is the best way to manipulate the temperature of these things? I dont have any sealant for my CPU, so condensation is an issue and it needs to be just above room temperature. I was thinking of experamenting with various heatsink/fan combinations untill I got it where it needs to be, but this might not offer enough control, especially when I start to overclock it some more.


Any other info or experiances with these things would be much apreciated, because I'm basically running off the supprisingly limited info google has to offer and am still very much in the dark.

Thanks!

[aspire.comptech]

I would highly advise you to join the www.xtremesystems.org forums as they are much more knowledgable about the more extreme methods of cooling your cpu.

[Sui]

1. What is the best way to attach it to my ATX powersupply?

uhhh with a blow torch

will it supply the device with only what power it wants?
is it going to try and cram all 19A down its throat and burn it out?

Yes .... no

Is there any truth to this?

There are many levels of truth, but I don't really get what you were talking about.

2. What is the best way to manipulate the temperature of these things? I dont have any sealant for my CPU, so condensation is an issue and it needs to be just above room temperature. I was thinking of experamenting with various heatsink/fan combinations untill I got it where it needs to be, but this might not offer enough control, especially when I start to overclock it some more.

Run a program that ensures your cpu always has a load. Adjust further by a fan controler on the heatsink. MBM can turn on a program when your cpu temp gets too low, but youd have to find a cpu burn program designed to run with command line options.

Peltiers are a PITA, which is why I would water cool way before using a peltier. If your pelter fails it won't just insulate your cpu from the heatsink, it can produce heat and help cook your processor. BTW go buy some insulation.

[Nitestick]

a peltier should generally be used with water cooling anyway, as the combination of a HSF and peltier doesn't achieve very good results due to you either having to use a weak peltier or there being excess heat from the peltier.

in short, don't mess with peltiers unless you REALLY know what you are doing.

[cwiz]

Originally posted by nitestick
in short, don't mess with peltiers unless you REALLY know what you are doing.

i agree, when peltiers go bad, things go south real fast. u def want insulation cuz peltiers get real cold. conversly the other side gets real hot, air cooling is prob barely enough to keep up with it.

[joshd]

the thing with peltiers... i am sure you know that they have a cold and a hot side. the heat generated on the cold side is transferred through the peltier to the hot side (hence why they get cold and hot). This means that with an 80W peltier, you need to be able to take 80W plus the amout of heat your CPU gives off away from it. this is why people general water cool a pelt.

insulation isnt as necessary as with more extreme types of cooling, as it is very unlikely that you will have load temps below 0. (the idles should be though).

but yea, as aspire said, the best thing to do is read the F.A.Qs in the T.E.C cooling section of www.xtremesystems.org/forums .

Ultimate Guide to TECs
http://www.xtremesystems.org/forums/...ad.php?t=38367

The "What power supply can be used for my TEC" thread
http://www.xtremesystems.org/forums/...ad.php?t=28294

hope that helps.

[cwiz]

Originally posted by joshd
insulation isnt as necessary as with more extreme types of cooling, as it is very unlikely that you will have load temps below 0. (the idles should be though).

bout the only thing more extreme than peltier devices is phase change.

and the chip doesnt need to be 0*C to need insulation... all the peltier has to do is get below the dew point which is proabably around 10*C or so depending on the average ambient temperature and relative humidity at the time. at 0*C, the dew freezes, it doesnt form. the dew point could be higher, or lower, than 10*C. it all depends and imo hardware is too expensive to leave to chance.... on a rainy day u could get fried.

[specialblend218]

I wouldn’t consider an 80W pelt of the CPU. Since it’s 80W at 15.2v that means the current is 5.26 amps. Since you want to run it off the 12v rail on the power supply the current will still be 5.26 amps but the voltage will now be 12v, which means the pelt will be able to cool 63.1W (assuming 100% efficiency, which will never happen). I didn’t see you mention what CPU you are planning on using but all CPU’s except some of the mobile versions will output more then 63.1W of heat, many CPU’s will out put over 125W of heat especially with a good over clock. If the pelt can’t absorb all the energy it will then act as an insulator eventually crashing/shutting down the computer or frying the CPU.

[joshd]

Originally posted by cwiz
all the peltier has to do is get below the dew point

a mighty good point you have there....


specialblend: it depends on what you have cooling the pelt. if the cpu outputs 100W and the pelt only 80W, if the thing cooling the pelt is perfectly comfortable with 180W+ load, then it should be fine, and you wont break the cpu.

if the cooler is not that good, and can only manage a 130W load for example, you would be better off without a pelt at all.

to get the best TEC cooling, the higher rated the pelt the better really. a 225W pelt will easily manage sub-0 idle temps and possibly load temps, depending on the CPU, however, they pull alot more power. its a tradeoff between power consumption and performance really...

if it were me, i would go a tad higher than an 80w pelt for a good temp reduction, but you should really be looking at water cooling for the hot side of the pelt.

[Nitestick]

all the peltier has to do is get below the dew point which is proabably around 10*C or so depending on the average ambient temperature and relative humidity at the time.

it also depends on altitude.