The fan will spin up as needed. It is temperature controlled. I am not surprised yours doesn't budge considering you do not have a GPU (listed in your sig at least) and you are only pulling less than 150W at worst.
That said, in order to get on the list here, a professional review is required.
I'm so sorry for not writing a GPU in my signature xD, i forgot!
I'm using GTX 650 Ti factory Oveclock.
So it's consuming more than just 150W.
But yeah, i would guess its comsuming less than 550W, because i have for like a 3 to 4 months now, and fan, except at boot, never was spining.
I'm not saying to put it on the list, but just recommending it, because of looks, brand and noise.