Finding the CFM of my case fans

[starbuck]

I have a thermal take VM300a case(the skull case) and it has 4 fans which have the following info(from their website)

80x80x25 mm, 2050rpm, 21dBA

I'm guessing then that these are 80mm fans(prob very obvious). Trying to quieten down my system and been looking at these. Firstly, is there any way of finding out roughly how much CFM they shift as don't want to replace them if it means losing cooling. Also, is 21DBA average or quiet for case fans?

If it is suggested I replace them, can anyone suggest good alternatives, ideally I want it as quiet as possible but as cool as possible(rather have it cooler than quieter)

[StormPC]

21dBA is quiet.

Most manufacturers and resellers (Newegg included) give the CFM right in the product listing. No need to guess.

Water cooling might be right up your alley.

[Flibb]

21 is quiet, what are your current systems temps and do you overclock? The noise can be comming from the powe supply fans, CPU cooler or even your graphics card cooler. Might be worth disconnecting tthe case fans, then booting the PC up, see if it makes much difference (temporarilly). ALso the fan grills / covers can add a lot to the noise.

[YorkieBen]

thermaltake have been known to fib/exaggerate about the dba rating on their fans - the fans on the Tsunami dream, or on the silent tower cooler for example were both louder by all accounts than what thermaltake said

[silon]

YorkieBen, thermaltake is considered decepting users aint it?

starbuck, i hav a coolermaster praetorian, and it has 2intake and 2outake [one at the rear and one at the top] and although rated at 21dB, they make a lot of noise.
i switched off the front intake fans, and put vibration dampeners to the rear and top fans. alot of the noise could be coming from those fan grills and dust filters on the intake fans... and since i didnt want to remove the dust filters, i opted to switch the fans off instead.
my temps seem to hav increased a couple of C, but i dont really mind, the silence is more important to me...

[Butcher]

30-40 CFM free-flow is typical for case fans.