Quiet case fans

[ElementalDragon]

Ok.... i've lately been on a rush of trying to get my PC as quiet as can be even with it's mesh side panels and space for 5 case fans (3x 92mm, 2x 80mm). i should be getting my Arctic Cooling Freezer 64 Pro CPU cooler Friday, which should knock noise levels down a tad..... probably gonna wait till the Arctic Cooling Accelero X1 VGA cooler comes out and order that to knock that noise level down a couple notches too. one thing i'm curious about is.... anybody know of some REALLY quiet case fans that i can get on Newegg or TigerDirect or somewhere that are 92mm since i'd like to stick wit just using the 92mm's and forget about the 80mm. Or.... i was kinda wondering..... would it be a bad idea to use a 92mm-to-120mm case fan funnel, and get an Aerocool Turbine fan for the rear fan? do Funnels cut down the cfm a fan is able to pump out at all? Those turbine fans seem to do pretty good at a rather low rpm and low noise levels.

 

[iceman7311]

i believe since the funnel would be restricting some of the air it would be loud.

 

[Admiral Michael]

i believe since the funnel would be restricting some of the air it would be loud.

Thats what I was thinking as well, the restriction could cause more noise.

 

[Mainframeguy]

ED - all I can read sounds like a noise nightmare - if you wnat quiet you have to build it that way up from the outset (or just be INCREDIBLY lucky)....

please allow me to direct you to a forum where they seriously know what they are doing if you want a quieter machine - silent computing review is here and I cannot recommend them highly enough - just be respectful, hey? They seriously know their stuff and will guide you if you want help in that one respect...

 

[ming]

Surprisingly, my case fans aren't that loud... it's my Northbridge fan that makes the noise of a concorde in my machine. Spins at 8000rpm according to the BIOS and there's no way of me making it quiet.

 

[ElementalDragon]

i was just recently pointed to these fans by a fellow HL2DM'er. lol

http://www.xoxide.com/thermaltake-silent-cat-92mm-fan.html

they seem to be pretty freakin quiet... and possibly quieter than my current fans. i say POSSIBLY cause i have no idea what db rating my fans are. the 80mm ones of the same type aren't really much louder. any opinions on those?

 

[LeeJend]

Funnel - bad idea. It compresses the air thus increasing the velocity which increases air flow noise. The back pressure the fan has to work against also goes up which will probably increase bearing noise depending on the design.

My PC noise level now is mostly (WAG about 2/3) air whooshing in the front panel through the restrictions the front grill creates.

If you're sure the noise is coming from the case fans use a fan speed controller to tune the speed for least noise without raising your case temperature significantly.

There was an interesting link I posted in another thread. It shows the "normalization" of the sone sound level system vs frequency and hearing detection level. Basically, perceived sound levels drop by a factor of two as you lower the frequency in the 500Hz-2.5khz range. There a re several sweet spots.

Slowing the fan reduces air flow noise, bearing noise and since it also drops the frequency by dropping the RPM picks up an advantage from the ears frequency response.

My fan controller lets me drop the speed enough that the annoying bearing noise is almost inaudible compared to air flow noise. My cooling loss was about 1-2 deg C on case temperature which did not affect the CPU or GPU temperatures.

I've got one of those Thermaltake Fans on my CPU HSF. It is pretty quiet and high CFM. I run it at reduced speed and CPU HSF noise does not get out of the case. It was even pretty quiet on the bench. The airflow noise was significant compared to bearing noise.

Surprisingly, my case fans aren't that loud... it's my Northbridge fan that makes the noise of a concorde in my machine. Spins at 8000rpm according to the BIOS and there's no way of me making it quiet.

Yes there is. I explained how in another post. Splice into the red and black wires and add a speed controller or dropping resistor. All you have to do is take the edge off the speed and it makes a marked difference.

 

[ElementalDragon]

well.... the front panel of my case has a built-in fan controller of sorts..... the speed that the one fan in my case is running at now is around 14xx. and there's no filters or anything on the fan, since it is an exhaust fan..... don't really see a point to a filter to filter dust from LEAVING the case. Think the noise may be from my CPU or VGA fan.... or a combination of both..... but i think i'd rather wait till the Arctic Cooling Accelero X1 comes out to replace it.... so i at least know what THAT fan will have to offer. my Arctic Cooling Freezer 64 Pro should be here Friday according to the tracking status... though it may get here tomorrow, since it's already in Philly.. bout an hour away.

So....... u think those Thermaltake ones would be a good idea to get even if it's just one 92mm for exhaust? fresh air into the case isn't a problem cause of the mesh..... and without the secondary side panel for the 2 side-mounted 92mm fans... there's even less blocking fresh air from going in.

edit: just took my side panel off cause i'm gonna hook one of the fans i took out up to the fan controller to see EXACLTY how noisy they are..... and it also does sound like my VGA fan is most of the problem.

 

[ElementalDragon]

hmm....... actually.... now i'm kinda curious. i plugged in one of the spare 92mm fans..... and that thing is freakin whisper quiet.... and seems to run at a much lower RPM than the one i have hooked up in the back. with the spare hooked up, and turned all the way down, i can barely hear the thing even with my head next to the fan. sadly i don't know what DB rating they are.... otherwise i'd know if getting the Thermaltakes are worth it. even though they probably are anyway, since they more than likely have a much higher rate of cfm's than these.

 

[LeeJend]

Holes in your side panel and you want quiet? Did I forget to mention that I put 1/8 inch cork on the insides of my two side covers and run low RPM fans on the front panel to compensate? The cork absorbs the noise from the GPU and CPU HSF. Adding the cork had no effect on case temperature.

The cork is what was absorbing most of the GPU cooler noise with my 9800 PRO. With the new X800XL it runs at 60% RPM which is pretty quiet until I start gaming and then the game noise drowns out the rest of the PC so I never notice it except right after I exit a game. Then the GPU HSF RPM stays high for a 30 seconds until the GPU cools back down.

If the 7800 GT doesn't have fan speed control then the case side is what you want to go after.

As a test set the PC on a table and walk around it (or just turn the case). Your ear is sensitive to +/-1dB and is free test equipment. You will be able to tell where your acoustic hot spots are (left, right front back).

Mine are front and back right now. The sides are quiet. Yours will probably be the side with the holes. If so tape the cardboard back to a notepad over the holes. You'll get a noticeable improvement. Check the case/GPU/CPU temps and see if they stay pretty much the same. If they do get some cork. If they go up more than 1-2 deg C try a small, reduced speed fan in the case front to get the cooling back.

Your CPU and GPU fans are pointed right at that side panel so it is the key to quieting the system.

PS Watch the CFM. If it goes too high you replace whinign with whooshing which is an improvement but still undesireable. I'm trying to figure out how to get rid of the Whoosh now.

AS for the thermaltake fans with the slits in the side. They seem to reduce whooshing and whining which was a nice improvement on my CPU cooler.

 

[Xenoboar]

if u want something with a good dB to CFM ratio, check out some of the SilenX fans

92mm, 38 CFM @ 14 dBA

Might be a bit expensive for your tastes though :lick:

 

[ElementalDragon]

uuh...... Lee...... i don't think you quite understood what i meant by "mesh side panels". i don't mean a hole here and there for a case fan like you find on acrylic..... i mean something like This. If you can find a notebook with cardboard big enough to cover that..... by all means show me. lol. and the 7800GT does have automatic fan speed control. it's just really whiney. it's not air noise as far as i can tell. and it's nowhere near it's warmed-up state to be on high speed.

As for the Thermaltake case fans..... i believe they WOULD be a rather nice improvement in exhausting and even intake if i can get them into the side panel that holds them in my case. the 80mm fans that i currently have that came with the case supposedly move 34CFM of air at 3,000 rpm's, with a noise rating of around 30db (at average RPM's, which 3,000 RPM's is it's average). so...... since the speed controller on my case didn't let the 80mm's get NEAR that (only let them get to like 900rpm-ish), i'd say it's probably somewhere around 1,000 rpm's moving 10.xCFM of air, at around 10 decibels. now the Thermaltake 80mm fan moves about the same amount of air.... but at 2500rpm's.... and only 21 decibels. so.... in THEORY..... the Thermaltake fans should cut down on case fan noise drastically, even though there really ISN'T any case fan noise. and the AC Freezer 64 Pro shouldn't be near as loud as the stock fan that i have on now according to Arctic Cooling's website.... and it'd be likewise for the AC Accelero X1 AND the NV Silencer 5 rev. 3.

Edit: yeah.... Xenoboar.... i was already pointed out to the SilenX fans by the same HL2DM'er buddy that pointed me towards the Thermaltake fans. not really willing to spend around $17usd for a single fan when apparently the fan controller on my case restricts the fan speeds to the point where they're damn near not even audible to a DOG'S ear.

 

[Xenoboar]

Arctic Cooling VGA Silencer NV5 (Rev3) for your 7800

 

[Aprox]

I see that you are talking about mesh and holes and such and I recently realized that my front fans were louder when my front bezel was on then when it was off. This logically led me to the conclusion that the holes for my intake fans where restricting air flow creating more noise and hurting "performance".

I took a drill and doubled the size of the holes (all 240 of them) then deburred and counter sunk them. Here is a pic I took when I was half way done.



I realize this falls outside the context of your question.. but I hope this helps you in your quest for a quieter computer

 

[Mainframeguy]

Surprisingly, my case fans aren't that loud... it's my Northbridge fan that makes the noise of a concorde in my machine. Spins at 8000rpm according to the BIOS and there's no way of me making it quiet.

Yeah there is! And I have one going free in a box that would not fit my neo2 thanks to the AGP slot position and an arctic cooler on the 9700 in there! A passive NB heatsink will do the job, believe me - so if you want one carriage should not be much - that is all you need pay me and it is yours (only cost me under $10 a couple of years back!

Oh and ED - looks like from the thread you maybe never did click that link I gave - because if you do it will give you access to all you need to know.... Not knocking OSNN, just this whole subject is kinda 0wned by that forum

 

[ElementalDragon]

i did click it.... just didn't feel like lookin all over the place, or signing up to forums, just to ask a question or a few.

Aprox: that looks..... like it had to suck. lol. i'm pretty sure the holes for the fans on mine are large enough. they're somewhat large squares..... maybe 1/4" square. and not much metal between each square. LOTS of air flows through those puppies.

Xenoboar: ....yes.... i know about the NV Silencer 5 Rev 3. i'm just kinda waiting for the Arctic Cooling Accelero X1 that's coming out sometime in February (hopefully early Feb.).

Arctic Cooling Accelero X1 and X2 reviews @ Virtual Hideout

 

[Mainframeguy]

...
I realize this falls outside the context of your question.. but I hope this helps you in your quest for a quieter computer

looks more or less bang on topic to me! Rep++ although those nutters over at SPCR would INSIST the only way is removal of the whole "holes/mesh" and replacement with wire cage or bare hole.... they are right too - that is the quietest... but your solution retains looks and is probably more than half way there....

 

[ming]

Yeah there is! And I have one going free in a box that would not fit my neo2 thanks to the AGP slot position and an arctic cooler on the 9700 in there! A passive NB heatsink will do the job, believe me - so if you want one carriage should not be much - that is all you need pay me and it is yours (only cost me under $10 a couple of years back!

MFG, where did you get the HS from? I can't seem to find any suitable HS for the nf4 board as my vid card sits right on top of the NB.

 

[Mainframeguy]

Aha - sounds like the Neo4 has the exact same fan/AGP placement as the Neo2 did then - and I am guessing you also have an arctic cooler on your card? Anyways - when I have time I will fidn a link or take a pic for the HS - right now I am the proverbial blue ass fly as we say here...

 

[Admiral Michael]

I took a drill and doubled the size of the holes (all 240 of them) then deburred and counter sunk them. Here is a pic I took when I was half way done.

I like you solution, Reps for you!