[TerraMex]

Hey.

Just to clear a few points.
The point on using a chiller is to have sub ambient temps, making a more "active" radiator. (pardon the expression)
You exchange the radiador connected to the loop by the chiller.
You will not have a standard radiator in the cooling loop because it will add heat to the water , due to the fact that the water is below ambient temps. And the radiator works both ways.

Said that, the chiller must be able to remove heat from the water , and maintain it's temperature (in a given interval of idle/load), working as an active element.

Assuming a standard cooling loop composed of CPU (overclocked), chipset and GPU (both with overclock) , you can get as high as 200W dumped in the water (or more).

For that to happen, it must be powerful.
A waterfountain is nowhere near as powerful as you might think. Most are rated for under 50W (some alot less). They work by cooling a tank of water, which is not used continuously, and it's maintained cool by switching on and off the engine when the water temperature reaches the edges of a given temperature interval (set) . So it has time between uses and temperature variations, to work down the temps.

You'll need the same engine as a prometeia/vapo (rated for 200W, 1/4Hp compressor or similar) . This way you'll maintain sub ambient temps, cool all three (or more) blocks and not worrying about temperatures . A good chiller controls the temperature by the same method, switching on and off to maintain the temp in a interval.

Things to worry about is in idle mode , the temps dropping below freezing (and create condensation), and in load mode, the engine not being able to keep up and/or not being able to operate in continuous duty (most aren't).

And no, a fridge heat engine doesnt do the trick, most fridge engines aren't rated for dealing with that type of heat. However , a freezer have alot more powerful engines, and I know a couple of guys over here who sucessfuly converted one into chillers. Althou they are massive (bigger than a cube case). The deposit consumes most of the space for several reasons. Some time delta between switches, and a large reservoir gives them that time , while maintaining temperatures between the given interval (set) , and a large reservoir takes alot of cooled water making the temperature changes "less hard".

Temperatures will be defined by the size of the reservoir, the power of the engine, and the time it is on and off. Of course, if you have a small res, then it has to work more and harder, and vice versa, less and not as hard, and you can even get a "not-so-powerful-engine".

Or, you can go Peltier (but i'm assuming you know the pros and cons of that, if not, there's a thread about swiftech's chiller in pHaestus worklog to give you an idea).