I have a tiny n54l HP microserver, its super compact but perhaps to a fault as the airflow isn't great. I was thinking about replacing the existing fan which is about 100cfm with a stronger one that is about 150cfm (likely noisier but can deal).

When I was looking for a replacement fan I came across was looks like multiple fan blades in one, while they didnt seem they would fit it got me wondering if perhaps instead of replacing my current fan, I could place another fan on the outside of my server where the air is getting exhausted by the internal fan, in effect doulbing up, the number of fans? And that is my question, would that actually increase CFM?

The reason I want to do this in the first places is my drives regularly get up to 46c and sometimes as high as 38c, and my interpretation of the google hard drive study that those temps are a bit much? The line that got me was "What stands out are the 3 and 4- year old drives, where the trend for higher failures with higher temperature is much more constant and also more pronounced." So I was worried that going up to as much as 48c for 3+ year old drives (some are 3-4 yrs old) was too much?

Related but separate, many of the higher cfm fans have 3+ wires, whereas the current one only has two i think, assuming I would just have it always running and not being "controlled" would that be a problem?

  • Be aware that depending on the design, a fans CFM can reduce rapidly if the resistance to that airflow is large. I'm guessing there's a lot of resistance in a tiny server, So you'll need a fan good for high Static Pressure. However, If the original fan is already good for Static Pressure, then adding another may not help as much as you would hope. Google Static Pressure Vs High Airflow. and Fan Curve. Also, btw, try get the fan to blow onto the hard drives?... as a rule of thumb turbulent flow cools better.
    – Stax
    Aug 30, 2021 at 0:20
  • Thanks for that, I was totally unaware of static pressure! I did get another fan but put it on the front to blow on the drives, seems to be working. will have to test a bit more but am hopeful. much appreciated!
    – DrZog
    Sep 17, 2021 at 22:03


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