When it comes to AIR Fans, whats important..

[NtheFace]

Whats important, and what should each fan be focused towards..

So first thing i should look for in a fan is PVM compatiable correct?

Then next airflow or rpms? Does it matter how fast a fan spins or just how much CFM it creates?

I have a 240mm fan on side panel.. can replace that with 4 140mms
So if my 240mm pushes 100 CFM and i can buy 4 140mms pushing 80CFM
Is the Math 4x80 = 320 CFM between the 4 over the 100CFM of 1?

Ive got 2x140mm fans pushing on my radiator, and 1 240mm pulling on my radiator, should i match the RPMS/CFM on the push/pull setup for your radiator

 

[Conumdrum]

fans do not have to be PWM. Many great really great fans aren't PWM. You buy fans that are good quality good CFM and good pressure for rads.

Get a fan controller for non PWM fans and use the mobo for PWM fans depending on the mobo.

Honestly, there are 1 billion variables, no perfect solution for each setup.

You do your homework, you buy stuff, you read lots of posts from a few good forums and read real fan tests.

Then you cool your PC.

Once your post count here is at 1000 and a few other forums, and you seek new info all the time, your questions will be answered, little Grasshopper.

Just read and buy stuff. And post, it's fun.

 

[johan851]

Is the Math 4x80 = 320 CFM between the 4 over the 100CFM of 1?

That's more or less correct. CFM is cubic feet per minute, so it's a measure of flow. If you have multiple things providing flow, it's additive. It gets a little complicated when you're dealing with pressure, though, which is why you see slightly different recommendations for things like radiators or heatsinks with tightly spaced fins. Some fans provide better pressure than others and will do a better job of pushing air through those gaps.

Honestly, the best thing to look for in fans is good reviews and good brands. Manufacturers lie, or at the very least, use wildly different methods to come up with their specs. You can't trust the noise figure much at all. RPM will give you a good general idea of speed, but that doesn't tell you too much either.

A few good brands are Delta, Sanyo Denki, Panaflow, Yate Loon, and Scythe. They're all known for pretty good quality fans. Read up on the particular models you're interested in to get an idea of how they perform. Fans that are known to be good quality typically last longer and perform better for a given RPM than other fans.

Then next airflow or rpms? Does it matter how fast a fan spins or just how much CFM it creates?

RPM is a good indicator of noise. CFM is what you actually care about, but due to different blade styles between fans, two fans of the same RPM may perform differently.