are you doing this to keep your pi cool, or is it for your 2pacs? My artic breeze USB fan is doing a wonderful job keeping my miners cool, but I have no fan on my pi. Could it be that my pi is overheating?
I thought the same thing and opened up the case for my Pi and placed it where airflow was better. I didn't make any difference. I would try it though never hurts.
Which Raspberry Pi version? Which powered usb 2.0 hub are you using? How many amps on the usb hub, that the 2Pac is plugged into?