I used a PC fan and what I did was hot glued a paper clip to my helmet and looped the fan on with that. That way it flexible to adjust where I want it. If that helps.
How many of you use helmet fans? And if you do where do you mount them?
I was thinking near the vents cut on the ear pieces but I'm afraid of too much sound distortion plus a constant stream of air on ones ears can be bad. Possibly on the cheecks?
I have a DP 96 and I tried the ears but it was way to loud. I did not have enough room for the checks. So, I put 1 just above my forehead and one at the bottom of the visor. It seems to work well.
I have two in my helmet, on both sides of my temples(of the inside of the helmet) blowing towards my face. Make sure you leave a space between the fans and the mounting surface, otherwise the fans will not work very well.