Suitable Fan Replacement for NV

SJMarty wrote:
I have an NV (purchased May, 2006) and the fan is getting noisy. The current fan is an ADDA AD0912HB-A76GL. .... The specs say the airflow is 52.5 CFM at 2900 RPM.

The datasheet for the AD0912HB-A76GL indicates that it's a PWM (4-wire) fan. I don't have an NV; does it have a 4-pin fan connector?

SJMarty wrote:
I purchased the Noctua NF-B9 due to all of the recommendations I found in the forum. Well, the fan was definitely quiet but it didn't push enough air to keep my NV cool.

That one is a 3-wire fan. The 4-wire version is the NF-B9 PWM. It's true that those Noctuas do not flow as much air as the original fan -- static pressure is much lower, and even in free air the Noctuas only flow about 40 CFM -- but that shouldn't matter too much unless the original fan was usually running near its max RPM. Is it possible that the Noctua failed to keep the NV cool because it wasn't the 4-wire version? (Or because it was mounted backward?)

And... How did you determine that the NV wasn't being kept cool enough? Were the reported temperatures outside the normal range, or were they just higher than with the original fan?

SJMarty wrote:
I found a possible replacement...the StarTech FAN9X25TX3H. The specs on this one say the airflow is 48.4 CFM at 2600 RPM. The noise level is 33 db(A). The only spec I can't seem to locate is the amperage rating.

I'd be very surprised to hear that it draws more than the original fan's 250mA, so I don't think that's a concern... But it's not really quieter than the original fan (assuming that the original fan isn't making more noise than usual due to bad bearings).