TEC temperature controller

Hi, I'm new here to the forum
I was hoping for some help or input from you guys to get a good temperature control for a TEC. I'm thinking of cooling my future core i7 with a high cooling power TEC, somewhere in the 437W range, direct die of course, a little undervolted for efficiency. I'll be cooling the hot side with 2 triple TFC radiators and 3k rpm ultra kaze fans which for 24/7 use will be undervolted, only when benching they'll run at 12V, that should provide the necessary cooling for the hot side.

Now for my question, I would like a good temperature control for the TEC to keep condensation to a minimum for 24/7 use. I know it has been done before, but I can't seem to find anyone who explaned it decently or that had a good temperature control. I read that someone on the forum used a t-balancer to do it, but is it effective and accurate? Basically I need a temperature controller that controls the power provided to the TEC, according to the cold plate temp that is measured, around a setpoint that is set in the controller.

I have no idea how well or how "fast" TECs respond to temperature control when given a sudden CPU heat load for example, if anyone has an answer to that...
Wouldn't it be more accurate for example buying a temperature controller with build in functions like PWM, PID control to get a better automated temperature control?

For example here is a link to one of the many manufacturers:
Temperature Controllers and Thermal Management Solutions
They sell a pretty decent temp controller, but of course you need the H-bridge amplifier to be able to control high power TECs.

I'm just looking for a good solution for 24/7 use to keep condensation to a minimum... Any input is welcome on what instruments to use etc!

Thanks and hi to everyone since I'm new here
Edited by Nighthawk82 - 3/16/09 at 11:28am

Well, I know it won't be easy to keep an i7 cool, this forum is filled with that kind of observations, you're right, but maybe I'll cool it in the less efficient range then
It should still be possible right, with very good watercooling present.

Are there precedents of people achieving a decent overclock (+4.2ghz) on a core i7 using high power TECs? Let's say I run the TEC at 80% Umax for benching. I know every chip is different but still. If anything, when done right the achieved overclock should be better than on water only right.
For 24/7 use I won't be using an extreme overclock so that shouldn't be a problem. I just don't really know what overclock can be achieved with let's say a 437W TEC at 80% and 2 triple rads cooling the hot side and a D5 pump. And only for the lower overclock for 24/7 use I'll be using the temperature control, for benching I'll set a low temperature setpoint so that the TEC is constantly powered at for example 75-80%.

I actually read about someone using a 288W TEC and keeps his temps below 30°C under load with an i7 965 @4.1ghz, so that looks like a good indication, although it was probably run more likely at 90% Umax or something, so that seems to leaves some headroom for a higher cooling power TEC with high-end watercooling.
Edited by Nighthawk82 - 3/16/09 at 12:30pm

I knew it was you, I read your entire thread, actually I read couple of them
Now that I have your attention...
How did you actually achieve the PWM function? I know you used the t-balancer which sends a signal proportional to the temp difference that needs to be neutralized, but is that constant changing voltage interpreted by the mosfets to give a certain amount of power to the TEC? Or is the TEC just turned on/off during periods of time, powering it fully on/off. I don't think so since you say it's PWM and not on/off. I think I'm just confused as how the mosfets react to the signal coming from the t-balancer. Sorry if this is a stupid question, I got my engineering degree but too bad it's not in electronics, I just would like to give it a shot
I won't be using the t-balancer though, I think I found a nice stand-alone temp controller with LCD display and lots of functions (Omron), I just don't know how to make the connection controller-PSU, just buying and SSR would make it only on/off switching right and I'd like PWM for better accuracy.
Edited by Nighthawk82 - 3/16/09 at 4:11pm

Yes indeed, with SSR I meant a solid state relay. I actually have no experience with those, but since they are solid state and not mechanical, I thought they'd make less or no noise? Or am I wrong here
And yes, powering a TEC with a controller alone is nearly impossible, I've found a temperature controller that can handle quite strong TECs, but I bet those cost a small fortune. But as I said I won't be using a t-balancer or any other PC-related controller, I think I'll buy a controller used in automation, they are actually not that expensive and quite nice if you could integrate them in your system. I just need to get a clearer view of the middle circuit working between the controller and the PSU, so I can make an informed decision. Guess I'll need to read up on that
Btw, since PWM is actually on/off, isn't that gonna shorten the lifetime of the peltier element? I thought I read that somewhere, not sure anymore. I was looking for a way to supply the TEC with a constant changing voltage, not really on/off, the voltage depending on the heat load it has to carry of course. Or is that what you're doing... I'm a bit confused here

EDIT: I was thinking something in the direction of PID control, so that it reacts fast on the temperature differentials that arise because of a sudden heat load for example. That's also the reason I asked in my first post how fast TECs respond to a voltage change.
Edited by Nighthawk82 - 3/16/09 at 4:52pm