Question about axial fan mounting?

Well since I don't feel like registering for every damn marijuana growing website, I'll take this over to RIU. I came across Rumpeforeskin's guide to mounting/ lightproofing axial fans.

I was wondering if you could have better airflow if you put the fan in the middle of the bend, mated up to two of these(which is what he used, he just cut the spokes out):


pics are from rumpleforeskins guide, found here http://forum.grasscity.com/grow-room-design-setup/106154-step-step-light-proof-mounting-axial-box-pc-fan.html

I guess what I'm trying to ask is what would be the most effective way to mount the fan both to keep it lightproofed and get the most efficient cfm through the pvc. (On one side, in the middle..) Sorry if this still doesnt make sense just finished a lil sesh.

I'm going to have two of these in my new box, one for exhaust and one for intake.