kinda subjective here... not really get it
Is it a generally
(a) Random question according to size, RPM and total unit? OR
(b) Does it base on it's position inside the chasis & type of chasis?

my answer would be

(a) bigger size, bigger RPM, more unit amount - Much better airflow.
As for me, I'll goes for the 2x140mm since it produce less noise when run at full speed (mostly ppl don't use PWM controller and straight power using PSU).
Larger size = less rotation = less noise.

(b) If inside chasis, this will depend on ur airflow setup... and how clean ur cable management inside ur pc...
there is no use using more fans or bigger fans if all the cables are blocking the airflow... this depend on ur chasis design also

really arrr? seriously? hahaha... usually it just come ONLY went u bought their Nepton 240M
This is great new

didnt ur 540 air came with 2x140cm fan for intake? u wanna change it?
since u will be plugin all ur fan directly to PSU (and not really concern about noise), check their speed @ RPM of the fan...
Just check the RPM of that both 12cm & 14cm bitfenix spectre pro u mention...

E.g: 3x12cm fan (w/1000RPM each) VS 2x14cm (w/1600RPM each); that the 2x14cm is blowing lots more air compare to 3x12cm configuration... plus, more quiter also
So i would choose the latter... if iwas opposite... then choose the earlier...

This post has been edited by sue_cinta: Jul 28 2015, 01:15 PM

this evening went to viewtech, they also got silencio FP120... 1 full large bag... RM59.00/each
got one fella bought 4x of emm...

but still depend on type of fan also right?

either way, OP gonna blast everything directly from PSU...