Ahhh...its good to be back.
Just from the top of my head...
Radiator designs work on both sides of the equation, namely water and airside.
The problem with our intended application is that we've got fairly limited airflow using computer fans (especially with the noise restrictions) and an even smaller frontal surface area.
Both materials have their benefits and their disadvantages. For instance, in automotive, Alluminum has become the material of choice namely because it is cheaper, and production costs in volume is also lower. It however suffers from the difficult and expensive (replace it rather than repair it) possibility of damage.
Also, the problem with alluminum though is its limited conductivity compared to copper. Which isn't necessarily a problem if you've got enough of it spread out on a wide area like a car but it would be a problem if you have it say in a heater core or a PC radiator.
There's also the issue that the thinnest Alluminum fins are much thicker than that of their cupric counterparts because of its structural nature. In order for it to achieve sufficient strength it needs to be thick enough. Moreover, when you braze alluminum it sheds off a few layers of itself in the brazing process.
This thick fin tends to result in a greater airside pressure drop when placed into a core.
Copper radiators on the other hand employ a less sophisticated manufacturing baking process to alluminum's brazing. But these require more steps and distinctively more precise equipment (in some cases) to manufacture.
Off the bat you've got better conductivity and lower airside pressure drop and the potential for units with smaller footprints. Which doesn't matter as much in the automotive industry.
It loses out to alluminum in terms of cost of material and being far denser than Alluminum it becomes even costlier in terms of weight.
But its easily repairable and more corrosion resistant.
Copper Brazing or Cuprobraze®, is a very expensive technology considering the number of steps it has relative to the much more mature alluminum (nocolok) brazing technology and the equipment required.
Its primary purpose was to gain back ground lost when the automotive radiator industry alluminized back in the 70's.
Its distinct advtanges has all the great attributes of copper but enhances strength, durability, and doing so at lower material costs. The added factor is that its a greener process for the environment.
Cuprobrazed radiators and charged air coolers are targeted for heavy duty applications which have higher pressure/temperature requirements which Alluminum would eventually buckle under. Think huge trailer truck turbo diesels with 200psi and 200C up operating temps.
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