Low air resistance, low fan speed, low noise technique

Enclosures and acoustic damping to help quiet them.

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Katana Man
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Post by Katana Man » Mon Aug 08, 2005 6:38 am

fastturtle wrote:As to the modders mesh, have you ever tried fireplace screen mesh? I've got some of that laying about from another project and was wondering how it effects airflow.
No, I haven't tried that, but I know there are many good options that are much better than the factory bezel. The easier your computer can breathe, the slower you can turn your fans down. The end result is a super quiet computer.

Denorios
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Post by Denorios » Sun Aug 14, 2005 8:09 am

I think it's case fan grills that are by far the worst culprits. I use an LX6A19 with the original filter, bezel and accoustipack filter installed, and removing them hardly makes any difference. When I removed the case grills, on the other hand - woah! Most generic cases are more metal than grill anyway, and even the honeycomb design that high end PSU's use is extremely restrictive.

Some cases - I don't know why they bother having fan mountings at all, the flow is so restricted. :evil:

Incidentally, Katanaman, did you notice that the LX-6A19's rear grill is more restrictive than the front one? I was somewhat puzzled by that. :?

Katana Man
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Post by Katana Man » Sun Aug 14, 2005 12:51 pm

Hehe yeah, :) It's the first thing to go. I don't even take a new case out of the box unless my tin snips are within arms reach!

Denorios
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Post by Denorios » Mon Aug 15, 2005 1:58 pm

Katana Man wrote:Hehe yeah, :) It's the first thing to go. I don't even take a new case out of the box unless my tin snips are within arms reach!
All hail the tin snips! Cheapest and easiest upgrade I ever made. I swear, in my very low airflow (single 5V Nexus 120 rear fan), removing the fan grills has lowered the case temperature by 10C! Unbelievable!

vertigo
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Post by vertigo » Mon Aug 15, 2005 2:54 pm

single 5V Nexus 120 rear fan
You are perverse.

Denorios
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Post by Denorios » Mon Aug 15, 2005 10:43 pm

vertigo wrote:You are perverse.
Umm. Thank you. I think. :?

ronrem
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Post by ronrem » Fri Sep 16, 2005 10:56 pm

Building an intake base of wood,open to the rear,filtered,lets you intake through FLOOR cutouts. You can go further by fitting PVC pipe through the floor to duct air to the cpu,to the chipset etc. Having a rear opening/filter of about 4" x 7" should be non restrictive enough. The System would employ at least one rear 120 and a PSU with a 120 or 140. No significant sound is going out the floor-out the rear base inlet and around to reach your ears. You seal the case well otherwise. The size and position of the holes in the floor-or the size of ducts,determines the ratio of air sent to various areas,for instance,adding a small floor hole up fron means air to the HD mounts.

Going this route should work for almost any case. A little stain and Varnish and it can look good. It would add height and weight. I see a few noise concious cases do now use a floor inlet instead of front.

YngDiego
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Post by YngDiego » Sun Sep 24, 2006 11:40 am

What do people think about snipping the fan grills on the Antec Solo Lifestyle? They use a honeycomb gril, with pretty minimal metal so the flow appears to be pretty good. Has anyone modded the front of the bezel to allow for better airflow? Such as adding a hole in the front of the bezel, or removing some of the plastic around the edges where the air intakes are?

PopCorn
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Post by PopCorn » Tue Dec 12, 2006 8:31 pm

ok he has a good idea i give him credit for that... but if u dont have filters or something blocking dust from getting in the case and getting dust on the fins of the heat sink then that is blocking air flow on the heatsink and is preventing exactly what you are trying to accomplish, yes removing all the grills and stuff will lower your CASE temp but in the process your raising the cpu temp by reducing the airflow on the heat sink and id much rather have a case that is some what louder and have my proc last another year year and a half

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Post by qviri » Tue Dec 12, 2006 8:35 pm

You can always blow out the dust. Plus, do you really care if your processor lasts six years instead of four and a half?

Anyway - that post was in 2003. With 120 mm case fans, you can basically have the cake and eat it too.

Katana Man
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Post by Katana Man » Tue Dec 12, 2006 8:48 pm

I've been doing this technique on multiple computers for over 3 years now. It simply works well. Temps are low, and the dust buildup is minimal. I clean out the computers only once per year (at most). Maybe it's because the volume of air moving through is less than the traditional techniques, maybe my house is cleaner than average, I don't know. But it simply works very well, and I've never had to worry about dust build up.

casebuyer
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Post by casebuyer » Wed Jan 31, 2007 7:26 am

then how should we clean the case
is there a good machine for it

Katana Man
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Post by Katana Man » Wed Jan 31, 2007 9:08 am

I just use a vaccuum cleaner with a small attachment tip.

casebuyer
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Post by casebuyer » Wed Jan 31, 2007 2:09 pm

but some people say it might make motherboard etc. wont work because static electricity or something like that
is this any way true
also is blowing or vacuum cleaning a better solution
can a hair dryer do cleaning or is it dangerous of static electricity

jaganath
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Post by jaganath » Wed Jan 31, 2007 2:11 pm

To clean dust out of a PC you should only use a can of compressed air. Vacuum cleaners do have static electrical charge.

nici
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Post by nici » Wed Jan 31, 2007 2:51 pm

You can clean with a vacuum if you gorund it, there are also special tips available that don't produce static. However vacuum cleaners are noisy and i hate them.

A hairdryer is no where near powerful enough to blow out dust unless you make somekind of nozzle for it.

Anyway, i can't remember the last time i cleaned a case from dust. I simply don't get enough of it for it to be a problem. When i used the zalman flowers some dust got clugged near the center of the heatsink, that's about it. If i sweep the floors with a static thingie there is not much dust, mostly some cat and dog hair. If i look into a light i can't see any dust flying around. So for me filters are pointless.

Your CPU will likely last for twenty years even if it runs at 50c all the time. I have never heard of a CPU dying in normal use with a functional heatsink, if it dies it's most likely caused by the HSF, mobo or PSU going poopoo.

casebuyer
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Post by casebuyer » Fri Feb 02, 2007 9:41 am

where can i find tips for cleaning case with vacuum cleaner

nici
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Post by nici » Fri Feb 02, 2007 12:54 pm

What kind of tips do you need? IMO a vacuum cleaner is pretty easy to use. :P No seriously, do a search for vacuum ESD nozzle/tip or something similar and you should come up with something. I only found complete ESD safe vauum cleaners, but i only looked for a few seconds. My recommendation is to just get a can of compressed air though, one can lasts pretty long if you dont clean your case every single day.

casebuyer
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Post by casebuyer » Sat Feb 03, 2007 12:11 am

so basic theory is here
we should make a narrow nozzle so it can blow more pressured air
and how can we remove static electricity out from vacuum cleaner

ronrem
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Post by ronrem » Tue Mar 20, 2007 9:14 pm

casebuyer wrote:so basic theory is here
we should make a narrow nozzle so it can blow more pressured air
and how can we remove static electricity out from vacuum cleaner
okay...

Get some clear plastic hose with just a bit more inner diameter than your Vacuum's nozzle. Get a radiator hose clamp at the auto parts place and an alligator clip,a few feet of wire. Strip + clamp the wire to the plastic hose-attach Ally clip to the other end and clip to the case-the vacuum is now grounded-no static.

ronrem
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Post by ronrem » Tue Mar 20, 2007 9:21 pm

even easier-an antistatic wrist strap,just snug the velcro up but on the hose extension,not your wrist,there's a wire+clip on it.

Blacktree
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Post by Blacktree » Tue Jul 10, 2007 12:11 pm

Or you could keep one hand touching the case frame while the other is operating the vaccum nozzle. :shrug:

Olle P
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Post by Olle P » Tue Aug 04, 2009 3:15 am

I totally agree with the "all or nothing" concept.

Open paths have the advantage of allowing the use of the most quiet cooling components available.
The downside is that to create a quiet computer out of it every part in the computer must be quiet, since there's little or no dampening of any noise generated within it.

In the opposite corner we have the computer where the regular dust filters are replaced by some that actually do catch the fine dust! That computer can also have some serious sound dampening installed to muffle noise from loud components.

Cheers
Olle

Wilson
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Post by Wilson » Tue Oct 13, 2009 6:31 am

katana man's findings are consistent with what I had been suspecting for a while, it does seem like filters and fan grills increase resistance and so mean more noise and less airflow.

Im not sure I agree with teh 'all or nothign' approach though, I dont reckon the basic screw on fan guards do any harm, I mean the ones where its just a few metal rings guarding the fan from your probing fingers. Also the 'honeycomb' type fan grills as sometimes found on power supplies or case sides dont seem TOO bad.

Some cases have terrible fan grills on back and front which seem to have more metal than holes! I think those are the worse culprits, and filters are bad news too as far as noise is concerned. I am content to just clean the dust out of my case every few months isntead of using filters.

I dont usually bother with a vacuum, just stick my head in teh case and blow away, just dont breathe in and have some windows open, and magazine to fan teh air once the dust cloud is floating around :-)

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Re: Low air resistance, low fan speed, low noise technique

Post by Zirbmonkey » Mon Apr 12, 2010 9:10 am

I recently had a case fan die in my Cosmos 1000, which made a terrible noise as it died. So I and decided to get rid of some noise from my gaming rig.

I took a dremmel to the rear and top exhaust fan grills, cutting hex grills off completely. It made a noticeable difference in air flow (by feel) and was subjectively quieter as well.

I also grabbed a set of 500RPM Scythe 120s, to replace both the broken fan and remove the stock case ones. They don't really push much air, but between the 3 of them it's plenty. I kinda wish I'd used 800 rpm fans instead for a bit more air flow, but I'm happy with the ones I have.

Overall noise dropped a TON!

fsscott
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Post by fsscott » Mon Sep 06, 2010 5:37 pm

The A05n already has this! Except for the front bezel...

tvih
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Post by tvih » Tue Sep 21, 2010 8:33 am

Mostly a rather old thread, but I really do agree with the OP. I had a fan outside of a case, and it was essentially silent. Slapped a fan guard on it... sheesh, not even a hint of silent operation anymore. Gah!

It's also evident when you have a setup laying on your desk instead of stuffed inside a case. With the lack of grills, filters and walls and all that, there's no turbulence. Thus things are VERY quiet indeed.

Problem is of course that having your system outside of a case is not practical. And when it is inside a case, it's not really possible to get rid of all the turbulence. And personally, I'd rather not cut up an expensive case just to get rid of the grilles etc! Same problem with my current PSU, removing its fan guard would probably lower its noise, but warranty would be voided doing that. Plus, hoping to get the noiseless PSU soon.

I could theoretically remove the grille of the SG03 since it is removable. But right now the front fans aren't what are making the noise. Plus it does kinda ruin the look ;) Compromises, compromises... I suppose I could try removing the dust filters, though. (EDIT: Bah, I thought the fan filters could be removed from the frame, but no such luck... remove them, and you probably can't get them back in any sane fashion.)

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Re: Low air resistance, low fan speed, low noise technique

Post by whispercat » Thu Jan 20, 2011 4:05 pm

So, if I'm reading the ideas in this thread correctly, any impedence to air flow creates more noise?

While I was going through this thread, I thought of many cases that have front intake fans, with either a mesh front or some sort of partial grill.

1. Mesh
Image

2. Grill
Image

3. Honeycombe?
Image

4. Solid Front
Image

I was wondering then, if one had fairly quiet components, and all things being equal (if one placed the exact same quiet components inside each of these cases), which cases would end up being quietest (what order?)

Would the solid front case be quietest, followed by the most wide open front intake?

datapappan
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Re: Low air resistance, low fan speed, low noise technique

Post by datapappan » Fri Jan 21, 2011 8:49 am

I'd say that, as always, it depends on many factors. A non-mesh front would hinder a direct sound path (=good), but then the opening left might be too tight, causing impedance (=sound, bad). Also, fans might give resonance noise in certain enclosures. So, no straight answer from me...

/ d

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Re: Low air resistance, low fan speed, low noise technique

Post by MikeC » Fri Jan 21, 2011 10:39 am

whispercat asks a very pertinent question... though I would put the 1, 2 & 3 case examples into the same group. I think datapappan is correct in saying it is dependent on many variables... but I would generalize this way:

1) If only modest airflow is needed, then a solid front w/ baffled (but not highly impeded) vents minimizes noise. Examples of such cases -- the LianLi pictured, Antec P18x series, Solo, others with extensive vents around the edge of the front bezel. (Note: Normal HDD mounting much preferred over side-ways mounting, which causes high impedance -- one of the main problems with that LianLi) Increase airflow and the baffles might cause enough turbulence to negate any noise-blocking benefit.

2) If higher airflow is needed, then the more open vents probably work better. There's something really annoying about the effect of air resonance in a mostly closed case with higher speed fans (or higher level of component noise); the noise becomes tonal. Personally I prefer the case to be completely open if the fans/noise is higher, this tends to keep the noise more broadband. Enclosing this noise just causes too much "booooom" effect.

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