Case Fan Question - Static Pressure Vs Air Flow
mambanegra
Posts: 594
So, one of my case fans is making a LOT of noise. It's one of three fans at the top beneath the filter and, if I touch the center and slow it down for a second, it gets nice and quiet, but then a few minutes later, the buzzing noise returns that is driving me crazy. So, I want to replace it (and possibly it's 2 neighbors).
So, should I buy static pressure fans to replace them since they lie under the filter?
The case is a full sized tower (as in...it's stupidly huge...probably not my best decision) and the fans are on top of the case.
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Comments
Before You do something hardware-ish maybe check out SpeedFan to control the speed of the fan and reduce it to a more silent level...
And choosing a Big Tower instead of one of the smaller ones can never ever be a bad choice... more empty space -> more air that has to be heated up before the system gets to hot... I only once had a mini tower and I'd never get one again... when gaming the temperature got close to the melting point of steel inside of it, and even adding half a dozen fans to bring in fresh cool air and suck out the heated air didn't help a bit...
Often there's a setting in the BIOS to allow the system to control the fan speed by itself.
You might try testing the fan out of the case to see if it's the fan itself, or the way it's mounted. If the fan is quiet out of the case, then re-mount it with a little masking tape between the fan and the case. Case filters are not supposed to drop much pressure, so airflow is probably more important. I gave up on mid-towers too.
In that case (no pun intended) the intake of air may have been too restricted then, or the air flow has been poorly distributed inside the case. You can't push more air through the case than can get in, you may even create a vacuum which just increases the problem.
Of course more space / air has a buffer effect, but if the air flow through the case is too small it will slowly heat up anyway. So more space alone isn't the solution (though a larger case will of course expel more heat because of a larger external surface). In general the amount of air passing through the case per minute is the most important. My rendering machine has a rather small case with not much empty space left, but a huge air intake plus several huge fans (two 8" push in front to cool disks and one 12" / two14" pull) and no overheating problems at all - my GPU rarely goes over 60 degrees C and its fans which are dynamic (speed controlled by GPU temperature) rarely over 60% speed.
For less than $10 just replace it. I've messed up so many fans trying to clean them.
I had three fans shoving air into the case from the front and side and two on the backside sucking it out. And I placed them so, that the airflow reached all parts that needed cooling without getting it into a "dead end" (wasn't the first PC I built myself, just the first mini tower
) though using an overclocked CPU and a gaming graphic card for all those 3d tank/ship/plane battle simulation games sure was another reason for a hot system.
Compared to that, the big tower I got now works great with only two fans.
Sounds strange, but size/speed/efficiency of the fans can vary a lot of course so it can be hard to compare two systems by the number of fans only.
Thanks for the comments, folks. The issue confuses me because the fan itself is only about 8 months old and it's two siblings are very quiet. It too can be very quiet except for those periods when it's not. It's not an airflow issue (the rattling continues when I open the top hood up effectively freeing up any intake blockage, though, there may be some stuff inside that may be doing some blocking of the airflow (large mesh wrapped bundle of cables from the power supply), and it isn't dusty. So, I'm assuming it's just a weird defect. I could try greasing it like some youtubers show, but I'd have to purchase the lubricant and I suspect it's a balance issue or mechanical defect so I'm just buying a new fan.
Anyway, I'm splurging on this: https://www.amazon.com/gp/product/B00CP6QLY6
If it really is as great as everyone says, I'll probably grab two more and replace the others. It would be nice to have a super quiet machine. Any thoughts before I hit the checkout button?
Static pressure is not necessary just for a dust filter. They are used primarily for pushing/pulling air through a radiator. The Noctua you linked is fine for your use.
Can't go wrong with a noctua. They ugly, but the quality is top of the line. I can hear my cpu ckicking and some coil whine over the noctua fans in my machine, even when I got em cranked up to 100% lol.