No proper treatment.
I have a couple of portable panels for tracking though, and my mics/pres aren't bad I suppose.
Edit: Facepalm is directed at me, not you.
That's kind of relative term. Because it's in my office, I haven't really considered its noise level in the context of recording. It has wide blades that move at a relatively low speed -- I can't hear it when it's on, but that's not saying a lot. It is quieter than the fan in my laptop. Just bear in mind that this is coming from the guy who records in an untreated room in which there is one computer and NAS devices, each with fans, plus I have tinnitus, so I may not be the best judge of silence.The intercooler shelf looks good so long as it is silent?