"The radiator is the same size a standard 240mm form factor and is constructed from aluminum instead of copper. Why aluminum? It sheds heat faster than copper and is lighter to boot. That brings up some concerns about galvanic corrosion between the aluminum radiator and copper coldplate, but Corsair and its partner CoolIT use a proprietary coolant mixture that prohibits algae growth and inhibits corrosion. If it is still a concern, the five year warranty on the H100 should pretty much close that gap. In five years it will be upgrade time with new hardware and new cooling designs anyhow."
FULL STORY @ OVERCLOCKERSCLUB (http://www.overclockersclub.com/reviews/corsair_hydro_series_h100/)