Ok, I think I understand your point a little better. You've only got one goat, and you want him to have free run of the field, but only eat the grass on one side of the field. Because the conversation started about TECs and variable control of TECs I thought you were talking about a condensation control measure for TECs, not a condensation control measure for a PC in a refridgerator case.
How about turning off the fridge and opening the door when you turn off the PC? It really breaks the goat analogy but seems like it would work.
Also I think that the typical PC will rapidly overwhelm the cooling capacity of the typical mini-fridge.
The relationship of how much heat will move depends on the difference in temperature, a 10 degree C difference will move twice as much as a 5 degree C difference. Eventually the PC and the Fridge would find an equilibrium if the fridge was sufficiently capable of pumping that much heat. However, the fridge has limits. It is not designed for continuous operation, and was designed to overcome the leakage of heat into the cabinet and a couple of openings of the door throughout part of the day. I suspect the heat produced by the PC continously is likely more than a mini-fridge can handle.
In effect your TEC "attractor" plate would not be so much for condensation as to make up for the shortcomings of the fridge. So things have just gotten more complicated and using more energy to run, and condensation is still an issue. Really, phase change is an issue, and the water vapor in the air could easily see three phases in your sealed cabinet.
So, how do we use your big TEC to help out? Say we keep the case sealed and we force the air to circulate through a heat exchanger that your TEC is pumping heat out of. Now we've cooled the air, and since we are forcing all the air past the coldest point, we can design ways to prevent the phase changed former vapors from circulating. Think about a shop vacuum, but on a much smaller scale as we only need to deal with the vapors in a fixed volume. The liquids and solids are separated from the gasses, and in our (sealed) case the cooled gasses are forwarded through the case again.
Sure, we've got inefficiencies all over the place, mulitple heat exchanges going on. Your TEC still needs to be cooled on the other side. But, we've now got cool dry air with no condensation worries around the parts we care about. Well, as long as we don't cool below the condesation point of all the vapors and we maintiain a decent vapor pressure, anyway. But that's been the crux of the problem all along, hasn't it?
Hmm... An air cooled system is immersion cooled, just immersed in a gas, eh?
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