Got a case with a cpu duct on the side panel. need a filter? replace with a fan???

imported_DaveA

Senior member
Oct 20, 2004
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Ok I just picked up this case:

http://images10.newegg.com/pro...mage/11-190-035-04.JPG

from a local computer store and it has a cpu duct on the side panel as you can see in the above picture.

should I buy a filter for the duct or should i remove the duct and place a filter along with a 92mm fan on it?

also if i place a 92mm fan on it is it recommended to have it as intake or outtake?


i currently have 2 antec 120mm fans in the case (1 in the front blowing in and 1 in the back blowing out) if that helps any.


Please give your advice/suggestions.

Thanks
 

BonzaiDuck

Lifer
Jun 30, 2004
16,052
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Some cooling mods, involving the reversal of the CPU fan from "blowing down" to "sucking up" from the heatsink, would be fine for using the side-panel blowhole as exhaust.

But you should try and balance intake and exhaust fans. Just as often or more so, this type of port serves as intake.

All intake fans should be filtered if you want to avoid frequent cleanups and dust-bunny removal. No exhaust fan needs to be filtered. Filters on intake fans are also going to reduce the effective CFM throughput of those fans. Thus intake fans should be as large as possible to avoid the noise of high-rpm, high-throughput fans in smaller sizes.

Putting an extra fan on the side-panel may help cool the CPU and motherboard a bit more, but the benefits of this sort of serial fan-placement are not as great as you would think they are.

Further, it will be bad enough, even with a filter, if the CPU fan is noisy, because the noise will still travel through the duct even if air-flow is in the opposite direction.

Applying the same experience and logic, putting a fan close to the side-panel (even a large, 120mm fan) and especially if it either sucks air through the blowhole or is bolted to the side-panel -- will increase transmission of fan noise in the latter case and increase the noise from air-turbulence in the former case.

These are the trade-offs you will make with blow-holes, which nevertheless assist much with CPU cooling unless you have good intake from fans (larger the better) in the case-front.
 

imported_DaveA

Senior member
Oct 20, 2004
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Originally posted by: BonzaiDuck
Some cooling mods, involving the reversal of the CPU fan from "blowing down" to "sucking up" from the heatsink, would be fine for using the side-panel blowhole as exhaust.

But you should try and balance intake and exhaust fans. Just as often or more so, this type of port serves as intake.

All intake fans should be filtered if you want to avoid frequent cleanups and dust-bunny removal. No exhaust fan needs to be filtered. Filters on intake fans are also going to reduce the effective CFM throughput of those fans. Thus intake fans should be as large as possible to avoid the noise of high-rpm, high-throughput fans in smaller sizes.

Putting an extra fan on the side-panel may help cool the CPU and motherboard a bit more, but the benefits of this sort of serial fan-placement are not as great as you would think they are.

Further, it will be bad enough, even with a filter, if the CPU fan is noisy, because the noise will still travel through the duct even if air-flow is in the opposite direction.

Applying the same experience and logic, putting a fan close to the side-panel (even a large, 120mm fan) and especially if it either sucks air through the blowhole or is bolted to the side-panel -- will increase transmission of fan noise in the latter case and increase the noise from air-turbulence in the former case.

These are the trade-offs you will make with blow-holes, which nevertheless assist much with CPU cooling unless you have good intake from fans (larger the better) in the case-front.



so i should just remove the duct and put no fan there?
 

BonzaiDuck

Lifer
Jun 30, 2004
16,052
1,681
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It depends on your tolerance for noise and choice of CPU cooler.

For the longest time and up until last month, I built all my systems with a side-panel blow-hole. You WILL get colder air going through the CPU heatsink fins, and you will also get more noise. Depending on your fan choice, whether you use noise-absorbent ducting or "foam-board ducting mod", and any number of things, this noise may include motor-whine or exclusively just air-turbulence. Because I wanted a high-througput CPU fan (more air-turbulence noise at minimum, even if no motor-whine), I closed off my duct, relying exclusively on the intake air from two slower-spinning, quiet 120mm front case fans.

With the ducting mod, I wanted the air-pressure from these fans to feed the CPU fan. I decided I could live without air from the side-panel, where the pressure is limited between the filter covering a single 120mm hole and no help from the front case fans because the duct separates the intake from the side-panel with the intake from the front case fans.

It took me a while through trial and error to get to this "optimum" combination for my recycled 90's vintage full-tower case. Your case has an advantage for the thoughtful placement of the rear exhaust 120mm fan port. If you can enhance intake CFM's from the front of the case at a very low noise level, you might consider blocking the side-panel port with plexiglass or PaxMate. But the side-panel blow-hole is one aspect of Intel's published thermally advantage case design -- a guideline to builders.

To you, it may factor into decisions about what CPU cooler to use, and what sort of fan should be on that cooler. I think if you were to use a larger CPU fan like a 120mm with an XP120 cooler or a cooler with a fan-adapter (higher-throughput, lower noise) you might be inclined to keep the blowhole, even if it is narrower than 120mm. Actually, that discrepancy could enable you to mix side-panel intake air with front-panel intake air. At one time I had a 92mm duct feeding a 120mm CPU fan, which was drawing air from around the duct as well as through it.

If you only have 80mm front intake fans or even one or two 92mm fans, you may be more inclined to leave the duct open.

My experience with putting fans on the side-panel, or even securing them to an internal case frame so that they sit near a hole in the side-panel, is that -- well -- I didn't like the extra noise. They are either going to make the side-panel vibrate and transmit those vibrations throughout the case, or you are going to hear some combination of motor-whine and air-turbulence.

Since noise is a subjective factor, cooling is a matter of what you're willing to live with, I can't give you absolute advice on this. I can't say "Do it this way or that way." You'll have to play around with it.
 

Tiamat

Lifer
Nov 25, 2003
14,068
5
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Nice case. In your case, i would reverse the cpu fan so it blows out of the side panel. I would probably make a slight mod to widen the base of the cpu duct so that if you have a 92mm cpu fan, all of the warm air will flow into the duct. You would not need a duct cover for this duct in this arrangement. You might want to get some air conditioning dust filter to cover up the AGP exhaust/intake holes.
 

imported_DaveA

Senior member
Oct 20, 2004
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well i have a zalman 7000alcu heatsink, so reversing the fan is impossible. the fan is a 92mm fan on the heatsink and the duct is 92mm as well.
 

sigpop

Member
Jan 5, 2005
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what case is that? i like it. i notice your pic is a newegg link. do you have the actual product link?

seems like i read about cases for intel should have that side duct to cool their cpus.