SPCR

I’m looking for 80mm fans to replace the stock ones in my NAS. The stock ones are

48.6-5-64.1 CFM
5.8 - 12.5 mmH2O
39.5-48.0 dB(A)

I’ve been unable to further narrow it down due to ambiguous labeling.

I tried a Noctua 80mm fan (Noctua NF-A8 PWM), and while it theoretically has a large CFM, the static pressure is too low.

55.5 CFM
2.37 mmH2O
17.7 dB(A)

Sucking in air through all the hard drive cages is apparently a little too tough. I have yet to systematically measure the system temp, but it is warmer.

So I have looking for a 80mm fan with the following characteristics:

Around 50 CFM
Around 5-7 mmH2O
Under 38 dB(A)

Welcome to SPCR,

What NAS do you have? Can you modify the case to ease air flow, and reduce the static pressure issue? Sucking air is actually an efficient thing to do, and it doesn't require a straight path.

Couldn't find a fan. But maybe you could stack two of those Noctua fans?

It doubles the pressure(4.74 mmH2O) and you should get something like 21 dB(A).

nonhinged wrote:Couldn't find a fan. But maybe you could stack two of those Noctua fans?

It doubles the pressure(4.74 mmH2O) and you should get something like 21 dB(A).

I saw a lengthy thread on that idea over on overclock.net, and the consensus was that, unless you could find counter-rotating fans, or place an air-guide to 'straighten' the airflow in between, the second fan would have little impact on air pressure.

Well, it doubles the "theoretical" and static pressure. The pressure you actually get depend on how restictive the case(or cooler) is at different flows.

Mocked up a graph based on some Noctua graph.