Fan questions ...

[Konrad]

Haha, call me a rookie.

I am aware that round 140mm fans can usually be screwed into square 120mm fan mounts, provided the adjacent volume can accomodate the 140mm fan, of course.

My roomy new mod case has standard screwholes for 120mm/140mm square fans. And lots of extra space all around which can easily accept substantially larger fans. Multiple 14cm fans are plenty hefty already ... but why not consider the overkill options of even larger, more powerful, quieter fans, eh? Left unrestrained, I'd probably go nuts and just install an industrial duct fan or blower or something, assuming I could find one that spins at less than about 60dB lol.

My first question (there's bound to be more, I'm sure, sorry in advance):
I see 160mm and 200mm fans out there. Will a round version of either of these (or of some other >140mm) fan sizes fit into standard square-140mm screw holes?

[TLHarrell]

Not usually without some modification.

[Konrad]

Aha, time to pull out ye olde power drill and holesaw kit. I'm thinking larger diameter fans can deliver similar static pressure at about the same noise level but in a thinner form factor. Hopefully allowing me to mount a thicker rad in a top exhaust push-pull setup. Going for positive pressure with high-CFM intake fans at front and sides.

Sealing up all those extra holes and cutouts, I want a "chimney effect" with fully directed airflow, I plan to use some plastic sheets and tubes to keep the hot spots cool and eliminate airflow dead/turbulence zones.

Can anyone recommend good anti-vibration material? I'm looking at semi-gel Sorbothane sheets, alas they don't seem to come in pleasing colours. Not interested in O-rings or corner pads or such, I want to cut full "fan template" or "air grill" shapes which won't leave even the slightest gaps. Yes, there's always some vibration, particularly at higher RPMs, but I plan to do what I can to minimize it.

I have heard old master ham radio greybeards say "a decibel is a decibel", meaning that all those extra little thoughts and touches which have trivial individual impacts can all really add up to a noticeable gain in quality when building a full system. I'm paraphrasing that into "a watt is a watt" for my PC build, why generate even one tenth of an extra watt (or decibel) when it can be avoided?