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Primary/Secondary Watercooling

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New Member
Jan 7, 2001
I got this idea from the theory of cooling pressurized water reactors (nuclear, that is). I've never heard it mentioned anywhere, so either a) no-one's thought of it or b) it's crap and doesn't work. The symbol sums it up... I'm probably smoking crack. :)

Anyway... here's how it might work...

You put a heavy-duty peltier on your CPU (say 150-180w) and watercool it. But instead of it going to a radiator, it goes to a reservoir with more peltiers on it, which cool the water in the reservoir and transfer the heat to a second watercooling jacket, which then goes to a radiator or whatever.

Now, my theory is that the primary circuit would be much colder than a traditional single-circuit system, but the secondary circuit would run much hotter. This wouldn't matter though, because you could keep the whole secondary circuit outside your case where it wouldn't really matter how hot it got (so long as the temperature stabilised somewhere that allowed the primary circuit to remain effective).

The problems I can see are:
a) the secondary circuit might actually exceed 100C, and if it did you'd have to keep it pressurized, which is difficult to engineer and would need a lot more than a few hose clamps to hold together.

b) nuclear reactor cores are a lot hotter than CPUs and at this temperature level, it just might not be worth it.

What do you guys think?
The process you are referring to is an intercooler and has been mentioned many times on this board. Bear in mind that your primary cooling system will probably be below ambient and so you will need to insulate it and the cpu from condensation.
So it's worth doing? Well, the CPU peltier would be insulated anyway since that would be well below ambient, so it should be enough to lag the primary circuit pipes and joints, at least inbound to the primary exchanger. I should try this. I just need some more peltiers and PSUs. :)
Maybe better idea?

I've thought about pumping heat from the radiator out back to radiator in. I admit this only works for radiators which excange much heat, I have a heater core, so that should be no problem. This would save you a second pump and all you need is 2 simple waterblocks which doesn't need to be engineered to fit onto processors.
The hose insulasion seems like a wise idea, here at the university (i'm chemist) we use cotton surrounded by aluminium folie (thin layer stuff).

Let me all know what you think of it. To me it seems more safe and effective than TEC cooling your CPU directly.
I've go a marine heat ecxhanger for cooling oil with water ,,it uses 3/8 lines and 1" hose ,its got about 20 - 1/4" x6" copper tubes in it ,it would prolly keep up with a car radiator ,and would fit inside a case,.. Imagine the chiller you could run on 1" hose !!!if you wanna try some stuff w/it lemme know and it's yours :)
What would be the best method? I think you could either put another waterblock on the radiator end and sandwich a peltier between it and a 3rd waterblock, which then goes to a bigger radiator. Or you could just take the fans off your radiator on the primary circuit and immerse it in a reservoir through which the secondary circuit water is pumped.

Or maybe something like Joe said where (if I got this right) you have a radiator that's actually designed to cool one fluid with another.

My personal opinion is you'd get the lowest temps with a peltier on the CPU, and if you also got peltiers involved in the secondary heat exchanger (i.e. that which moves heat from the primary circuit to the secondary). That way you ought to get very chilled water in the primary circuit, which would let you use a very powerful peltier on your CPU.
It would prolly be more effective and cheaper if you used a freon old bar fridge evaporator in the reservoir. I've also thought of building a secondary water chiller you can get 2 blocks designed for 3 peltiers @ http://www.overclock-watercool.com under the chiller section one guy did it with a large radiator and two custom waterblock and 6 pelts got a water/antifreeze temp of -18 to -24C coolant temperature.

ya ,my idea was to use the heat exchanger to cool one liquid to cool another to cool a peltier , because of the massive hose size you could use a car radiator and not restrict the flow