Noise Reduction On The Cheap

[Skillian]

My current pet project is to try and quiten my PC. Current noise makers are 2 case fans, stock AMD 60mm CPU fan and the PSU fan.

I'm soon to be getting a 60-80mm adaptor for the CPU fan, so I'm thinking of hooking that and the two case fans to a fan controller. Hopefully I'll be able to turn the CPU fan (and the case fans) down at night or when the CPU is idling.

My PSU is pretty cheap, and pretty noisy. I have already replaced the fan in the PSU with an old case fan I had lying around and it's now a bit quieter, but it will be the loudest thing in my system as I can't control the speed.

Main question is: should I replace the PSU fan with a thermally controlled case fan such as this Antec (http://www.ebuyer.com/customer/products/index.html?action=c2hvd19wcm9kdWN0X292ZXJ2aWV3&product_uid=56770)and stick the temp sensor to the side of the PSU or would this be dangerous?

I'm not sure how these fans work and at what temps they start speeding up or down.

[Virtualbody1234]

All those ideas are very good except... Don't use a fan controller on a CPU fan. Some fans don't start at lower than rated voltage so that is deadly for a CPU. Get a slower rated 80mm fan.

Antec makes power supplies (True series) where the fan is thermally controlled and that also have power connectors made for (only) controling case fans. The case fans end up turning at the same speed as the power supply fan. They run at about 1500 RPM. Very quiet.

Then there are the graphics card fan, the northbridge fan and the hard drive that are the remaining noisemakers.

I have fitted a 80mm fan to my graphics card. Removed the northbridge fan and added a large heatsink instead. And installed a Seagate hard drive.

[bigdawgfoxx]

How did you remove the small fan and put an 80mm fan on ur GPU?

[Virtualbody1234]

Originally posted by bigdawgfoxx@5 April 2004 - 14:12
How did you remove the small fan and put an 80mm fan on ur GPU?
A 80mm fan is supported by a bracket (mounted to the PCI slot at the back of the case) that is independant of the graphics card. Placed right under the card and blowing upwards.

[FlyingDutchman]

When you need help Skillian, I'll try to offer some.

For the moment, don't buy anything yet.
First make a plan, then execute it.

Provide pictures and specs of your rig so we can visualize your problem.

What's your budget?
Can you make things yourself (craftsman ?) ?
What tools do your have?
What is your goal? Somewhat quiet, or almost silent?

Regards.

[bigdawgfoxx]

Well I know how to put a fan underneath the GPU, but there would still be the 60mm fan on there to make noise. So putting an 80mm fan on it wouldnt make it any quieter.

[Skillian]

I can't do any any close up pics, my digital camera is bust at the mo, but there are some general pics and specs at this thread (http://filesharingtalk.com/index.php?showtopic=96564&hl=built+my+first+computer+today) from the day I built it.

350W generic PSU
XP2500+ Barton oced to 2.08 GHz
2 X 256 Crucial PC3200
Maxtor DiamondMax Plus 9 200 Gb
MSI K7N2 Delta-L mobo (NForce 2, FSB 400)
Sony DVD Burner
1 X side intake fan, 1 X exhaust fan
I broke my Ti4200, so I'm using a passively cooled GeForce 2 MX for now. This will be updated sometime after April 13th B)

Got pretty much standard tools, no dremel though.

I don't have a particular budget, if it's worth it I'll spend money but I'm not a rich man so cheap is good.

I would rather spend a little money for a decent improvement than spend loads on an almost silent solution. I also consider looks to be important which is why I want an aluminium case fan with a controller rather than a quiet black one.

I am no craftsman but I am reasonably handy and I'm willing to try most things, replacing the PSU fan is about as technical as I've done so far.

I'm thinking now that Vantec Stealth fans might be a good idea for the CPU and the PSU, 21 dBA sounds nice and quiet but is 27 CFM a good enough airflow for those important positions?

Thanks VB and Flying Dutchman for your input. Bigdawg, I assume VB took the 60mm fan off the GPU, the 80mm is to replace it.

[tesco]

Originally posted by bigdawgfoxx@5 April 2004 - 15:47
Well I know how to put a fan underneath the GPU, but there would still be the 60mm fan on there to make noise. So putting an 80mm fan on it wouldnt make it any quieter.
obviously he took the 60mm off :rolleyes:

i sorta did the same thing, my vidcard had no fan on it and the memort gets really hot so i get artifacting at stock settings in some games (actually all direct3d games) so I took an 80mm fan and sceqed it onto the heatsync using one screw in one corner hole and one along a beam that holds teh fan together (hard to explain) but its on there pretty tight and the fan hangs over the edge of teh heatsync cooling the memory on the bottom of the card, the ones on the top get cool air from my intake fan at the back...i wish my cpu would run at right coltage so i could see what my temps would be if i had a normal cpu :(

[atiVidia]

a wierd idea i came up with earlier (http://filesharingtalk.com/index.php?showtopic=105347)

i still think it mite work :lol:

[Virtualbody1234]

Originally posted by bigdawgfoxx@5 April 2004 - 14:47
Well I know how to put a fan underneath the GPU, but there would still be the 60mm fan on there to make noise. So putting an 80mm fan on it wouldnt make it any quieter.
The fan on a GPU isn't 60mm. It's more like 40mm.

Anyway, I did remove that small fan. I still have intentions to add small heatsinks to the video ram chips and to replace the GPU heatsink with a better one. Perhaps a stock AMD cooler that I could cut so that it would be a low profile heatsink.

[bigdawgfoxx]

Can u just pull the 40mm fan off?

[FlyingDutchman]

Hi Skillian,

Ok, let me first try to explain why your PC is kind of noisy right now.
Tomorrow I'll have time to explain how you can do it in a different way, and bring down noise considerably.

From your links i found the case has several venting openings, at the top, two in the rear, in the side, and in the front (low down).
I suspect you have 1 fan in the side pumping air in, one in the rear pumping air out, and the PSU pumping air out. Then there is the CPU fan recirculating air. Then you probably didn't close any openings not fitted with a fan. (Right so far?)

The supply of fresh air brought in through the side will manage to keep you CPU cool, but then the "polluted air" (It has been warmed as it has cooled the CPU, thus it is polluted) is allowed to spread freely through the case.

Now you have 2 fans expelling air from the case (PSU-fan + the case fan), and one feeding air into the case, directly to the cpu. The 2 expelling fans probably displace more air than provided by the fan in the side panel, so they will suck in some additional air through the other vents. It is a pity 2 of those vents are located right next to the expelling fans, so air will take the route of least resistance and enter the case right next to the expelling fans. You have a "cooling-air short circuit" here.

Your cooling is in-efficient and thus the fans have to work overtime to provide enough cooling.


I had to guess a lot here, so tell me where I guessed wrong.

The PSU's intake, is it all in the front (where the cables exit), or are there also holes at the top?



Originally posted by Skillian@5 April 2004 - 19:32
Main question is: should I replace the PSU fan with a thermally controlled case fan such as this Antec (http://www.ebuyer.com/customer/products/index.html?action=c2hvd19wcm9kdWN0X292ZXJ2aWV3&product_uid=56770)and stick the temp sensor to the side of the PSU or would this be dangerous?

The web site says: "Built-in temperature sensor" , so the sensor is probably located under the fan's hub. You would be very lucky when you could make yourself a good "temp controlled" PSU by modding it with this fan.

More tomorrow....


EDIT: 12 hours later.....

Finally found better pictures of the case in this review (http://www.dreamstation.cc/reviews/computer/enermax_cs-3051l/) .
The review isn't very favorable, I mostly agree with reviewers. :unsure:

Most 'bad features' can be cured though without spending loads of money.

[Skillian]

You were pretty much right about the assumptions you made. The vent at the top is pretty useless, not much room for air to flow and the turbulence this causes makes it noisier than it should be, so I don't use a blowhole. The front fan would have absolutely nowhere to draw any air from, so thats pretty pointless too.

Should I close the openings I'm not using?

The reviewer is right about the side fan, is doesn't flow over any important components, but it does let a lot of air in, and makes quite a difference to my temps. I also don't really seem to have a dust problem.

The exhaust fan grill again doesn't let enough air out and causes noise, but I use it because it does help, and I sometimes unplug that fan at night. I'd like to cut that grill out really, but I'm not sure I have the tools.

The power supply only has a grill at the back where the wires come out, nothing underneath unfortunately.

Thanks for taking the time to check it out for me, it's appreciated.

[FlyingDutchman]

Originally posted by Skillian+6 April 2004 - 20:43--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Skillian &#064; 6 April 2004 - 20:43)</td></tr><tr><td id='QUOTE'>You were pretty much right about the assumptions you

made. The vent at the top is pretty useless, not much room for air to flow and the

turbulence this causes makes it noisier than it should be, so I don&#39;t use a blowhole. The

front fan would have absolutely nowhere to draw any air from, so thats pretty pointless

too.
[/b]
You could reduce turbulence, and the sound it makes, by mounting a fan on top of an old fan-frame. Just take an old worn out fan, break out the spokes, and use the frame to mount the fan on.



Originally posted by Skillian@6 April 2004 - 20:43

Should I close the openings I&#39;m not using?

Generally speaking: YES &#33; , unless an opening has been identified as an air-intake of course.




Originally posted by Skillian@6 April 2004 - 20:43

The reviewer is right about the side fan, is doesn&#39;t flow over any important components,

but it does let a lot of air in, and makes quite a difference to my temps. I also don&#39;t

really seem to have a dust problem.

The exhaust fan grill again doesn&#39;t let enough air out and causes noise, but I use it

because it does help, and I sometimes unplug that fan at night. I&#39;d like to cut that grill

out really, but I&#39;m not sure I have the tools.

When fresh air doesn&#39;t reach "components to be cooled" and doesn&#39;t thoroughly mix with hot air before it gets expelled, it&#39;s just a waste of "expelling capacity".

Tools needed are "tin snips", a "nibbler" or a "dremel-like" gadget. Those that have worked with "tin snips" before swear by it. Be aware there are "right walking" and "left walking" tin snips.

<!--QuoteBegin-Skillian@6 April 2004 - 20:43

The power supply only has a grill at the back where the wires come out, nothing underneath

unfortunately.
........[/quote]
Not really a problem though.

I have to work on an answer for you, and can&#39;t do it tonight anymore.
You can start searching for low revving 80 mm fans (< 2200 rpm) available to you.
2 2800 rpm fans can be used too as rear-case-fans when you connect them in series, effectivly running them @ 6 Volts.
Don&#39;t buy yet, just see what is readily available.

I&#39;ll get back to you tomorrow, or the day after.

Regards.

EDIT:

See if you can find this Nexus-Real-Silent-Case-Fan (http://www.silentpcshop.nl/index.php?pnr=05&product=33).
It seems to be made for you. When you can&#39;t find it, that shop ships internationally.

[clocker]

Skillian,

After months of nonstop experiments with air cooling I have a few pointers....get out the salt.

1) If possible, always use a 120mm fan. It will move more air with less noise (especially if run on 5 or 7 volts).

2)Blowholes will work, but they need to be fairly large...in your case apparently a 120mm hole will remove the stock vents...I&#39;d do it.

3) Try flipping your rear fans to bring in air, your chip/heatsink should benefit. Remove the stock grillwork NOW.

4) At the same time reverse the fan on the back of your PSU so it is an intake.
(Do this only if you install the blowhole fan and your PSU has grillwork on the front for air to escape....)

5) Leave your stock front fan in place (ineffective as it may seem)&#39; it won&#39;t hurt.

Should you implement all these changes you will have a lot more air coming in (voltmod all these fans to run on 5/7v) and only one exhaust fan...the 120mm blowhole fan ( run this on a rheostat to balance flow/noise).

Such an arrangement has worked quite well for me...your results may vary.

[Skillian]

OK, the quiet fans I will have a look for - I did find these Zalman Stealth Fans (http://www.overclock.co.uk/customer/product.php?productid=16935&cat=428&page=1) - at 20dBA and a slightly higher airflow than the Vantecs they sound pretty good. I&#39;m thinking one for the PSU and one for the CPU.

I&#39;ve had a look around and I don&#39;t have any of the tools needed for cutting the grills or a hole in the top of my case. In theory I could buy them but I am trying to keep the cost down. What exactly would I need. Tin snips to cut the grill and some sort of sanding tool to neaten it up I guess. Those wouldn&#39;t suffice to cut a hole in the top though, as I would be cutting through sheer metal. Perhaps I could perform the easier modifications now and look at doing that later, when I have a bit more money and I can see clearer what needs further work as regards noise and cooling.

Remember my goal here is noise reduction, so I am wary of adding more fans, though I understand the concept that if the cooling is more efficient, less power would be needed to the fans, thus reducing the noise.

Do you think I should try reversing the exhaust fans even if I don&#39;t have a blowhole? I suppose that&#39;s something I could try and see for myself, I&#39;ll have a go tonight.

[clocker]

CompUSA sells a reasonable set of sheetmetal nibblers for ten bucks...they are what I have been using and work quite well.
With a bit of practise you can make a hole so neat that it really doesn&#39;t require any clean up to speak of.

The Zalman fans are quiet, but I&#39;d think twice about using one on my CPU...big performance hit with the low flow.

Go ahead and try the fan reversal...you have nothing to lose but time.

[Skillian]

Is that what I should ask for, sheetmetal nibblers? I don&#39;t want the hardware atore guy to laugh at me :rolleyes:

I was also wondering if that airflow was strong enough. Does anyone know what the CFM of a stock AMD fan is (that&#39;s what I&#39;m using currently using)?

Is it fair to compare the air flow of a 60mm to an 80mm? i.e. if the airflow of the AMD fan is 30 CFM, should I expect the same performance from a 30 CFM 80mm fan?

[james_bond_rulez]

wow this is amzing....we are into the aerodynamics of the computer air flow now...

this is deep stuff :lol:

y&#39;all are here wastin&#39; ur time on expensive noise reduction ideas but in the end, ur attempts are all futile, with all the money spent modding the case and buying fans when you could&#39;ve bought a cooling system for the same amount of money.

Why not use a water cooling solution? it&#39;s quiet and doesn&#39;t require fans...well except for the psu <_<

there is one on sale on ebay, grab it before somebody else does ;)

Cooling System (http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=3473230144&category=164)

btw i am not the seller, i am not that low <_<

[Skillian]

These are cheap noise reduction ideas, not expensive ones. If I had loads of money I&#39;d probably get a Zalman Flower CPU cooler and one of those expensive low noise PSUs.

[kazaa2002]

Skillian, this noise reduction is not cheap, however
when this gets into the mainstream, it might be worth a look
for your next pet project

http://www.pcmag.com/article2/0,1759,1531416,00.asp

This Voodoopc Rage f:50 has no fans and no water cooling unit
the reviewer says it is very quiet but it is also very heavy. :rolleyes:

[Skillian]

20 decibels would be very good, and that case looks proper smart.

I don&#39;t much like the idea of having to join VoodooPC&#39;s Upgrade Assistance Program if I want to upgrade the graphics card though :unsure:

Fact is, when BTX cases come out noise reduction will be alot easier as it will seriously reduce the need for case fans and stuff. I&#39;d wait for that before buying a quiet ATX case.

[clocker]

Originally posted by james_bond_rulez@7 April 2004 - 13:19


Why not use a water cooling solution? it&#39;s quiet and doesn&#39;t require fans...well except for the psu <_<


Water cooling doesn&#39;t require fans?

With the exception of the Zalman Reserator and the Innovatec rads, most H2O rigs that I&#39;ve seen use large, high flow fans.

[tesco]

Originally posted by clocker+7 April 2004 - 21:59--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (clocker @ 7 April 2004 - 21:59)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-james_bond_rulez@7 April 2004 - 13:19


Why not use a water cooling solution? it&#39;s quiet and doesn&#39;t require fans...well except for the psu&nbsp; <_<


Water cooling doesn&#39;t require fans?

With the exception of the Zalman Reserator and the Innovatec rads, most H2O rigs that I&#39;ve seen use large, high flow fans. [/b][/quote]
I knew you would post disagreeing with that post...lol

anyway i wanna add that just because youve got watercooling doesnt mean that their wont still be heat in your case. there are many other heat producing things in a computer, such as teh northbridge, souhtbridge, harddrive, videocard, optical drives and they all need sufficient airflow too. then where is all the heat from your radiator going, inside your case? all of that air also has to be removed from your case, so it ends up being probably just as loud, or atleast pretty close.

[FlyingDutchman]

Hi Scillian.

As said before, first you need a plan, then come up with a design, then execution.

The Plan:

Given the restrictions (resonable cost, should look good) it seems smart to:
* show as little as possible the tinkering done to the PC,
* try to establish the wished air-flow,
* reduce air-resistance so low revving fans can cope with their cooling task.

*as an extra I&#39;ll throw in a duct. You might consider using one.

Now this charts shows the problem we&#39;re facing:
Image Resized
Image Resized
[img]http://www.bijlard.demon.nl/Cooling/p-rpm2.gif' width='200' height='120' border='0' alt='click for full size view'> (http://www.bijlard.demon.nl/Cooling/p-rpm2.gif)
Below 500 rpm no fan is capable to produce a difference in pressure, and thus can move a reasonable amount of air. Higher revving fans can move air but above 2000 rpm their noise production climbs even faster.
For a given rpm small fans produce less noise than lager ones, but large fans move a greater volume.

From the chart you can see that in the rpm range we&#39;re aiming at (800 - 2000 rpm) fans produce a pressure of some .5 to 1.5 mm water pressure (1/32 - 1/16 " water). This is hardly any pressure at all, so air resistance should really be minimized.
Here is one example how you can lower air-resistance:
Image Resized
Image Resized
[img]http://www.bijlard.demon.nl/Cooling/Bend%20Spokes.jpg' width='200' height='120' border='0' alt='click for full size view'> (http://www.bijlard.demon.nl/Cooling/Bend%20Spokes.jpg)
Using needle nose pliers you can twist the spokes on the PSU&#39;s air-intake.
The picture was taken to show the difference, but the bottom row must be treated as well of course.

AMD advices to strive for an airflow like this, using a PSU with a bottom-intake.
Image Resized
Image Resized
[img]http://www.bijlard.demon.nl/Cooling/AMD-2.gif' width='200' height='120' border='0' alt='click for full size view'> (http://www.bijlard.demon.nl/Cooling/AMD-2.gif)
You have a PSU with front-intake, and a restricted front intake on your case, so let&#39;s strive for an airflow like this:
Image Resized
Image Resized
[img]http://www.bijlard.demon.nl/Cooling/Bottom_to_top.gif' width='200' height='120' border='0' alt='click for full size view'> (http://www.bijlard.demon.nl/Cooling/Bottom_to_top.gif)
This is the intended airflow so all the holes above the level of the AGP graphics card should be closed or fitted with an expelling fan. Especially these holes in the pic below have to be closed. The ones on the other side too of course.
http://www.bijlard.demon.nl/Cooling/bad_holes.gif

Here a few more examples of holes that need to be closed:
http://www.bijlard.demon.nl/Cooling/enermax-drivebay.jpg
and
http://www.bijlard.demon.nl/Cooling/another_hole.gif

Now mount 2 slow revving case fans in the rear.
Mount 1 slow revving case fan in the top
Mount a slow revving 120 mm fan in the front (blowing air in)
If you want, keep the LED-fan in the side, but disable the fan and close the hole with tape or plastic film.
When you haven’t enough air coming in, open up one or slot covers as indicated by the arrows here in the rear:
http://www.bijlard.demon.nl/Cooling/slot_covers.gif

These changes should quiet down your rig considerably, though you might need to change you PSU-fan for a less potent kind.

Continued in next post as the forum said:
"Sorry, but you have posted more images than you are allowed to"

[FlyingDutchman]

Continued from previous post:

Now, some drawings of a home made duct, guiding polluted air to the rear-case fans.
These pictures should explain it better than I can in words.
http://www.bijlard.demon.nl/Cooling/Hood1.gif

Image Resized
http://www.bijlard.demon.nl/Cooling/Hood2.gif' width='200' height='120' border='0' alt='click for full size view'> ('http://www.bijlard.demon.nl/Cooling/Hood2.gif')

[img]http://www.bijlard.demon.nl/Cooling/Hood3.gif

The idea is (depending on suitability of the CPU-heatsink) you flip the fan on the heatsink, so it sucks air through the heatsink. Then the hot air is caught in the hood and expelled from the case without a chance of polluting the case with its heat.
This results in the PSU taking in cooler air so it can get by with a weaker fan.


Think about it, and feel free to ask when you&#39;re not convinced.

Regards.

[FlyingDutchman]

Originally posted by Skillian@7 April 2004 - 20:33
Is that what I should ask for, sheetmetal nibblers? I don&#39;t want the hardware atore guy to laugh at me :rolleyes:

I was also wondering if that airflow was strong enough. Does anyone know what the CFM of a stock AMD fan is (that&#39;s what I&#39;m using currently using)?

Is it fair to compare the air flow of a 60mm to an 80mm? i.e. if the airflow of the AMD fan is 30 CFM, should I expect the same performance from a 30 CFM 80mm fan?
nibbler (http://www.xoxide.com/nibbler.html)

At the same air-flow (volume) a smaller fan produces a higher pressure.

Air-flow is roughly in line with: (size ^ 2) * thickness * rpm.

So, as the 80 mm fan is both larger AND thicker than the 60 mm fan, it is almost certain to displace a much higher volume.

[FlyingDutchman]

Originally posted by Skillian@7 April 2004 - 19:48
OK, the quiet fans I will have a look for - I did find these Zalman Stealth Fans (http://www.overclock.co.uk/customer/product.php?productid=16935&cat=428&page=1) - at 20dBA and a slightly higher airflow than the Vantecs they sound pretty good. I&#39;m thinking one for the PSU and one for the CPU.

I&#39;ve had a look around and I don&#39;t have any of the tools needed for cutting the grills or a hole in the top of my case. In theory I could buy them but I am trying to keep the cost down. What exactly would I need. Tin snips to cut the grill and some sort of sanding tool to neaten it up I guess. Those wouldn&#39;t suffice to cut a hole in the top though, as I would be cutting through sheer metal. Perhaps I could perform the easier modifications now and look at doing that later, when I have a bit more money and I can see clearer what needs further work as regards noise and cooling.

Remember my goal here is noise reduction, so I am wary of adding more fans, though I understand the concept that if the cooling is more efficient, less power would be needed to the fans, thus reducing the noise.

Do you think I should try reversing the exhaust fans even if I don&#39;t have a blowhole? I suppose that&#39;s something I could try and see for myself, I&#39;ll have a go tonight.
The fans at the dutch shop I named (link provided) are cheaper and absolutely the best.

Here a nibbler (http://www.xoxide.com/nibbler.html), albeit in the USA.

You are right, generally speaking, you should try to do with the least amount of fans (I have only 3 myself).

But, you said it had to look good. That makes it much more difficult in a case with a window.

[james_bond_rulez]

i got a headache.... :(

:lol:

[tesco]

Originally posted by james_bond_rulez@8 April 2004 - 21:06
i got a headache.... :(

:lol:
:lol:

flying dutchman, it looks like you really know your physics... :unsure:

[james_bond_rulez]

i know the physics, i am just a bit overwhelmed...

I got an A in physics during high school and I took a few Uni physics courses so ya I know my material ;)

[tesco]

Originally posted by james_bond_rulez@8 April 2004 - 22:08
i know the physics, i am just a bit overwhelmed...

I got an A in physics during high school and I took a few Uni physics courses so ya I know my material ;)
hmm, i did good in the electrical physincs stuff of grade 9, but this year in grade 10 physics im just so overwhelmed...and we only started 2 days ago :o

[Skillian]

Flying Dutchman, thanks heaps for your help. I think I understand what you&#39;re saying. I&#39;ve been away for a few days which is why I didn&#39;t reply sooner, but I will have a look through your ideas over the next couple of days and see what is feasible to implement.

As an aside, I got an 80mm CPU fan adapter on Friday and I haven&#39;t had a chance to properly test it out yet, though it seems to have reduced the sound a decent amount and dropped my load temps by about 5 degrees. The dominant sound from my rig now is a low whoosh from the 80mms, rather than the higher pitched whining sound from the 60mm. So some success already I am pleased to report.

[Skillian]

I had a play around last night:

At the moment I&#39;m using side intake, rear exhaust and CPU and PSU fans. None of these are quiet fans. From what I understand, you are suggesting adding three more fans at front, top and exhaust, and disabling the side fan. Yesterday I moved the side fan to the front and temporarily closed all other holes and case temps increased by about 10 degrees. The posistion of the front fan doesn&#39;t allow enough in so I won&#39;t use that as my only intake fan. The side fan is necessary to allow fresh air into the case. I think the CPU and exhaust are pulling this air over the mobo so it does provide some cooling to the parts. The front intake would only cool the front devices like HDD and CD, and the air won&#39;t reach the back of the case.

Twisitng the grill on the PSU is a good idea, the grill design is slightly different to the example, but I think it will still get good results.

I will try the duct, though for this to work I would have to reverse the flow of the CPU fan. I think I will buy two low revving fans, one each for the CPU and the PSU, and check my temps with those flowing in both directions. I still don&#39;t know a CFM to be aiming for when buying a fan for the CPU, so I will have to see how it goes.

This way only involves me buying two slow revving case fans, rather than 4 or 5 which at £10+ a go could prove pricey.

Sorry for the windy post, this thread really must be boring for everyone in here&#33; :lol:

[FlyingDutchman]

Originally posted by Skillian+12 April 2004 - 15:32--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Skillian &#064; 12 April 2004 - 15:32)</td></tr><tr><td id='QUOTE'>
I had a play around last night:
At the moment I&#39;m using side intake, rear exhaust and CPU and PSU fans. None of these are quiet fans. From what I understand, you are suggesting adding three more fans at front, top and exhaust, and disabling the side fan.
[/b]
Right &#33;

The idea is to establish a more efficient airflow for cooling.


Originally posted by Skillian@12 April 2004 - 15:32

Yesterday I moved the side fan to the front and temporarily closed all other holes and case temps increased by about 10 degrees. The posistion of the front fan doesn&#39;t allow enough in so I won&#39;t use that as my only intake fan.

Now you are telling me you mounted a 80 mm fan on a 120 mm grill. Did you tape the portion of the grill not covered by the fan? I fear NOT.
When not, air would be allowed to pass around the sides of the fan to the front, only to be recycled again. Please tell me you weren&#39;t THAT careless&#33;


Originally posted by Skillian@12 April 2004 - 15:32

The side fan is necessary to allow fresh air into the case.

I hope not, and hope to prove to you you don&#39;t need it.


Originally posted by Skillian@12 April 2004 - 15:32

I think the CPU and exhaust are pulling this air over the mobo so it does provide some cooling to the parts. The front intake would only cool the front devices like HDD and CD, and the air won&#39;t reach the back of the case.


Perhaps it helps when you change your point of view. Don&#39;t regard cooling as supplying cool air to hot parts. Look at it this way: cooling is "removing hot air from the case".



Originally posted by Skillian@12 April 2004 - 15:32

...
I will try the duct, though for this to work I would have to reverse the flow of the CPU fan. I think I will buy two low revving fans, one each for the CPU and the PSU, and check my temps with those flowing in both directions. I still don&#39;t know a CFM to be aiming for when buying a fan for the CPU, so I will have to see how it goes.

Now, when you do the "duct thing", imagine what will happen.
*- Hot air from the CPU is captured and expelled from the case immediately ----&#62;
*- Thus the CPU doesn&#39;t heat up the case anymore ----&#62;
*- The air in case will become cooler than it is now ----&#62;
*- The air to cool the CPU will be cooler than it is now ----&#62;
*- The CPU needs less air to be cooled ----&#62;
*- You can get by with less powerful fans ----&#62; noise reduction.


Originally posted by Skillian@12 April 2004 - 15:32

This way only involves me buying two slow revving case fans, rather than 4 or 5 which at

£10+ a go could prove pricey.

You can de-power existing fans by under-volting them.
A Zalman "Fan-mate" costs something like 5 pounds and is powerfull enough to regulate two medium speed fans (.5 Amps max)
Connecting two fans in series has them each operating at 6 volts and costs nothing.

<!--QuoteBegin-Skillian@12 April 2004 - 15:32

Sorry for the windy post, this thread really must be boring for everyone in here&#33;

:lol:[/quote]
The ones that are bored to death by this subject can skip it, and of course I hope to spread &#39;the gospel&#39; to more people than just you.
Air-cooling can be done so much better than it is usually done.

[Skillian]

I did block the air vents around the grill, along with any other holes behind the front bezel - only with sellotape but it seemed to be pretty airtight.

I still find it difficult to imagine efficient aircooling with only one intake fan and a very poorly placed one at that. Indeed my tests with it seem to suggest it is much less inefficient than my current set up.

This pic shows the ONLY vent at the front for air to get through to that front intake fan - with the USB wires in there it is close to useless.

http://www.tobitech.de/team3/heiko/images/globalwin/unten.jpg

[FlyingDutchman]

Originally posted by Skillian+12 April 2004 - 21:27--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Skillian &#064; 12 April 2004 - 21:27)</td></tr><tr><td id='QUOTE'>
I did block the air vents around the grill, along with any other holes behind the front bezel - only with sellotape but it seemed to be pretty airtight.
[/b]

Ok, you closed them. Glad you did. :rolleyes: :lol:


Originally posted by Skillian@12 April 2004 - 21:27

I still find it difficult to imagine efficient aircooling with only one intake fan and a very poorly placed one at that. Indeed my tests with it seem to suggest it is much less inefficient than my current set up.


My current rig doesn&#39;t have an intake fan at all. Air flows in naturally to fill up the space left by the expelled air. So, you can get by without.

<!--QuoteBegin-Skillian@12 April 2004 - 21:27

This pic shows the ONLY vent at the front for air to get through to that front intake fan - with the USB wires in there it is close to useless.
http://www.tobitech.de/team3/heiko/images/globalwin/unten.jpg
[/quote]
It would be improved a little When you place the case a little higher. Some books perhaps?

When you find your PC gasping for air don&#39;t forget you can open up the slot-covers&#33;
http://www.bijlard.demon.nl/Cooling/slot_covers.gif

[Skillian]

I&#39;ll have a further play around with the positions but so far my results are:

1 side intake, 1 rear exhaust - 30 under load
1 front intake, 1 rear exhaust - pushing 40 under load

sys temps, not CPU

It&#39;ll need a serious turnaround for me to switch that intake fan.

[FlyingDutchman]

Originally posted by Skillian@12 April 2004 - 22:07
I&#39;ll have a further play around with the positions but so far my results are:

1 side intake, 1 rear exhaust - 30 under load
1 front intake, 1 rear exhaust - pushing 40 under load

sys temps, not CPU

It&#39;ll need a serious turnaround for me to switch that intake fan.

Even 30 under load is too high, and of course you can&#39;t have a 40 degrees case temp when summer hasn&#39;t even arrived yet.
5 to 7 degrees over room temp is what I strive for.
But when you construct a duct we should see a marked improvement.

Man, I wished you were living close by, so I could lend you a hand.

[Skillian]

Originally posted by FlyingDutchman@12 April 2004 - 21:18
Man, I wished you were living close by, so I could lend you a hand.
Me too, perhaps you could bring your nibblers :D

[kaiweiler]

Originally posted by FlyingDutchman+12 April 2004 - 17:51--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (FlyingDutchman @ 12 April 2004 - 17:51)</td></tr><tr><td id='QUOTE'>
Originally posted by Skillian@12 April 2004 - 21:27

I did block the air vents around the grill, along with any other holes behind the front bezel - only with sellotape but it seemed to be pretty airtight.


Ok, you closed them. Glad you did. :rolleyes: :lol:


Originally posted by Skillian@12 April 2004 - 21:27

I still find it difficult to imagine efficient aircooling with only one intake fan and a very poorly placed one at that. Indeed my tests with it seem to suggest it is much less inefficient than my current set up.


My current rig doesn&#39;t have an intake fan at all. Air flows in naturally to fill up the space left by the expelled air. So, you can get by without.

<!--QuoteBegin-Skillian@12 April 2004 - 21:27

This pic shows the ONLY vent at the front for air to get through to that front intake fan - with the USB wires in there it is close to useless.
http://www.tobitech.de/team3/heiko/images/globalwin/unten.jpg

It would be improved a little When you place the case a little higher. Some books perhaps?

When you find your PC gasping for air don&#39;t forget you can open up the slot-covers&#33;
http://www.bijlard.demon.nl/Cooling/slot_covers.gif [/b][/quote]
My case is quite similar to this, I just set it on my desk with the front hanging over the edge about 3 inches to open up that airflow

[tesco]

Originally posted by Skillian@12 April 2004 - 16:27
I did block the air vents around the grill, along with any other holes behind the front bezel - only with sellotape but it seemed to be pretty airtight.

I still find it difficult to imagine efficient aircooling with only one intake fan and a very poorly placed one at that. Indeed my tests with it seem to suggest it is much less inefficient than my current set up.

This pic shows the ONLY vent at the front for air to get through to that front intake fan - with the USB wires in there it is close to useless.

http://www.tobitech.de/team3/heiko/images/globalwin/unten.jpg
my case had that problem too. i removed everything from my computer including mobo, cd drives, hard drives everything. even psu. then i removed the front cover from teh computer, and i first cut out teh fan grills as they were really small and let almost no air through. i then hot glued teh usb wires out of the way of the air flow, and i also had to drill holes into teh metal part of the case for the usb wires to go through; and i also drilled holes in the motherboard tray for the front panel connectors (power switch, leds etc) so that they arent in the way of airflow...removing the front panel is also necessary for installing a front intake fan i beleive, unless ur case is different...