How do i calculate my cpufan's cfm?

[Coolio]

how do i calculate my fan's cfm?:rolleyes:

[dimmreaper]

Easy, you don't. You look around on de net, finding whatever you can find out about the fan from it's part/model number.

[It_The_Cow]

Good point. It's probably not worth it considering what data what you'll need to know to actually be able to calculate it

[BillA]

the only "calculation" practical is from the mfgrs P-Q curve (which DOES exist, but may be quite hard to find)

however to use the P-Q curve one needs to know the backpressure (or suction) that the fan will be blowing into (or from)

and this necessiates a VERY sensitive manometer

or you can read the velocity with a thermal anemometer (under VERY controlled conditions) and then calculate the CFMs

or a good software program to generate much of this is Flotherm at $19,500 per seat (and the result must still be physically verified by modeling)

all of this is why the air cooling "design" of a professional workstation can cost over $500,000 - easily

so EVERY time you read an OCer describing CFMs, translate b.......t

no easy answers

be cool

[BillA]

aahhhhh ...........

in thinking a bit more about this, there is a way to get "on" the fan's P-Q curve (to get an idea of output)

with an optical (strobe) tach measure the RPMs, and the current draw (and voltage)

but now you're after another set of mfgrs data curves (they DO exist though)

be cool