Hmm.. it came with a sticky foam patch underneath it, so I used it to stick it onto the case..
I'm using a Lianli V2100 casing, and I just placed it on the block that is beside the PSU (PSU at the bottom for this case)
Thought that'd be a good location, but apparently no....
The stranger thing is it worked silently for quite some time, then this humming started, that's what gotten me vexed.