Yes, i read it. I use the same kind of fans. Mines are of 80CFM, too. And it isnt enough with my 220w floro setup, so try to imagine it with a 400w HPS.

What i was saying is that 12cm fans and more powerful or less noisy, take the hand you prefer.

But if you are going to use that fan, why do you ask? I offer you my experience about venting with PC fans, and all i said in my previous post still is valid. Take it or not, is your choice.