Interesting mod, a bit over the top just for colder air, but it would be really interesting to see how this would perform with much larger diameter and quieter fans. I wonder if a 120mm computer radiator fan at low rpm would be able to push enough air if funneled down into the two tubes? If so it would be virtually silent. If you could generate enough air flow and regulate between the tubes, replace the hot end fan with a third tube? Take something like a Noctua NF-F12 iPPC 3000 and funnel it down into the three tubes and see if it outperforms the three smaller fans. Now that would be over the top.