I found a 5v 30x30mm magnetic levitation fan that I have on my MM running 4s with a Neu 1515/1.5d.This fan puts out 4.9 cfm compared to a novak at 2.5cfm.
Where did you buy this fan? pics?
Also a question, I just manage to ARM my MM with 16.5V (5S a123) even with a custom Voltage cutoff :) anyway, do you think I can use the red wire from MM to power the fan (only) and still run 5S A123?