You, sir, must have been reading my mind.
I've been trying to figure out a way of making a more vertically-oriented radiator setup (compared to most of the horizontal box setups).. originally entertained the idea of making a semi-passive setup similar to Xine cooler system (rather than one continuous loop but tank to tank parallel tube system) utilizing a "cross-flow fan" and was struggling with the idea of having to solder all those tubes. I also saw the radiator setups from another company but they wanted obscene amounts of cash for their passive radiator setups.. Now you show this.. After seeing your work, now I'm inspired to build one.
Question for you... the interior of the radiators, is there a mechanism (ie - like blades or vanes) inside the radiator to increase turbulence inside and get more of the water in contact with the radiator surface? It's not much, but I think it's one of those "last 5%" type of modifications to get the most performance out of it.
Ozymand