MAby one could run spare vacuum cleaner hose from G5 fan intake to nearest air conditioner ?
Ham radio operators who became irritated with excessive fan noise have been known to put big fan outside and duct LOTS of cool air to tube amplifiers.
Then again ,I could just run one USB 2 cable to a USB hub installed in a case with 2 DVD/CD drives,card reader,mouse and keyboard leaving the CPU/power supply/noisy fans at least a couple meters further from my ears?