My CPU Duct (Pictures!)

Cooling Processors quietly

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josephclemente
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My CPU Duct (Pictures!)

Post by josephclemente » Tue May 11, 2004 11:30 pm

Wow, this is my 100th post. :)

I thought I'd finally post a picture of my CPU duct. It leads straight to my Zalman 7000A-Cu which cools my P4 2.53 GHz CPU.

The Zalman has been modded with a chrome fan (see my other thread in this forum).

Here is what the duct is made of:

1. Hole in case panel
2. Metal Mesh Pencil Cup, made by Rubbermaid. Purchased from Walmart. I cut out the bottom, made it a little shorter, and bent the opening where I cut it outwards. I like the trim ring on the top.
3. Plastic from CDR spindle. This is wrapped around the outside of the pencil cup. In the picture, it looks like there is a gap, but I have another piece of this plastic inserted to keep it all sealed.
4. Oil funnel. Also purchased from Walmart. Ensures incoming air does not bypass heatsink. Also holds the CDR plastic together at the end. Can slide back and forth for adjustment.
5. Duct tie plastic, seen on case panel side of duct. Holds CDR plastic piece together on this end.
6. Two blue LED lights, just above the duct. Looks cool through the mesh.

With the bottom of this pencil cup bent outwards, the inserted CDR plastic holds the duct in place, preventing the duct from falling out.

This duct allows me to run the CPU fan very slow (1065 RPM is the slowest my chromed fan will run on the Fan Mate - otherwise I'd go slower). Incoming air is much colder than using recirculated air like before. Noise and temperature is greatly improved!

Here is the picture (it is a little over 70K):

Image
Last edited by josephclemente on Sun Jan 07, 2007 2:14 am, edited 1 time in total.

Dhurdahl
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Post by Dhurdahl » Tue May 11, 2004 11:44 pm

Ohhh


Sweeeeet! :D

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Post by SometimesWarrior » Wed May 12, 2004 12:15 am

Thanks for showing your latest mod, josephclemente. Very cool-looking, as always. :)

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Post by Ralf Hutter » Wed May 12, 2004 4:48 am

Ooh! Schtylin' dood!

Can you post before/after case+CPU temps?

Skylined
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Post by Skylined » Wed May 12, 2004 7:28 am

Very nice!
I really like it!
God job! ;)

josephclemente
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Post by josephclemente » Fri May 14, 2004 5:48 pm

THANK YOU!

Here are my temperature results.

Running time per test: 2 hours
Ambient: 25.5C according to thermistor on cheap digital clock
CPU load: Idle running Windows XP

BEFORE: (no duct)

39C - Motherboard Sensor 1
39C - Motherboard Sensor 2
45C - P4 2.53GHz CPU
27C - Samsung 160GB SATA Hard Drive*

Reported fan speeds:

1110 RPM - 92mm chromed Evercool fan on CPU
??? RPM - SilenX 300W iXtrema Pro PSU
1156 RPM - 92mm chromed Evercool (front intake)
592 RPM - 80mm Nexus Real Silent (rear exhaust)

AFTER: (ducted)

29C - Motherboard Sensor 1
31C - Motherboard Sensor 2
31C - P4 2.53GHz CPU
27C - Samsung 160GB SATA Hard Drive*

Reported fan speeds: (fan voltage unchanged)
1065 RPM - 92mm chromed Evercool fan on CPU
??? RPM - SilenX 300W iXtrema Pro PSU
1156 RPM - 92mm chromed Evercool (front intake)
606 RPM - 80mm Nexus Real Silent (rear exhaust)

* Samsung hard drive temperature not to be trusted. See other threads on this hard drive's famous temperature readings. Otherwise, an excellent hard drive.

All of my fan speeds are very slow. The temperatures from before are not too bad - there isn't much airflow so I'm not surprised. But this simple duct takes my low airflow configuration into another world. :)

Smokeey
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Post by Smokeey » Sat May 15, 2004 10:56 am

Dude that looks suhweet!

Whats the noise like though now that you have the hole in the side case panel?

Also (stoopid question) is your CPU fan sucking or blowing (I presume its blowing from your description and pulling cold air from the outside).

luminous
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Post by luminous » Sat May 15, 2004 12:33 pm

I love the look of the case. I'm into Aluminium cases, its a shame most resonate :(

I'm also wondering what the noise levels are after the mod?

Did I mention that it looks nice...:D

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Post by loren_brothers » Sat May 15, 2004 12:47 pm

Very sharp!

josephclemente
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Post by josephclemente » Sat May 15, 2004 1:50 pm

Happily, there is almost no noise difference. I can detect a slight difference if I get up very close and completely cover the hole. I'm sure it would be another story if I set all my fans to max speed.

The CPU fan is blowing down onto the heatsink.

Originally, I was planning on somehow modding the CPU fan to pull air out of the case. This made sense, because it would prevent heating the case with CPU air. I knew from experience with my Shuttle XPC (small formfactor case) that exhausting the CPU air was way better than pulling CPU air in.

However, with my current fan configuration, it seems to cool very well. I was pleasantly surprised that even my motherboard temperatures improved so much.

A few of the many things I am interested in:

1. Using a temperature probe on the hard drive to get a better idea what is going on there.
2. Try doing without the lower front intake. See what happens.
3. Do something about the front intake's tiny holes. Has anyone with the same case played with these yet?
4. Getting a fanless PSU (Antec Phantom, if it will ever stop being a phantom). Then I'll try it internally and maybe externally if that doesn't work out.

Smokeey
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Post by Smokeey » Sun May 16, 2004 6:04 am

Yeah the improvement in motherboard temps is certainly a nice by-product of the duct. Maybe its due to the fact that the duct itself is open mesh so a small part of the incoming air is escaping through the duct 'walls' and cooling the innards of the case?

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it's wrapped in clear plastic...

Post by NeilBlanchard » Sun May 16, 2004 7:13 am

Hello:
Smokeey wrote:Yeah the improvement in motherboard temps is certainly a nice by-product of the duct. Maybe its due to the fact that the duct itself is open mesh so a small part of the incoming air is escaping through the duct 'walls' and cooling the innards of the case?
Except that it's wrapped in clear plastic... :wink:

Smokeey
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Post by Smokeey » Sun May 16, 2004 9:46 am

:oops: :oops:






:wink:

grandpa_boris
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Post by grandpa_boris » Sun May 16, 2004 10:40 am

what about the temperatures under load, like prime95 or one of the CPU burners?
josephclemente wrote:The CPU fan is blowing down onto the heatsink.
i am quite curious what the temperatures will be if you do reverse the fan, especially under a heavy load? i would expect higher noise and lower MB temperatures with little effect on the CPU. but it would be fascinating to find out what would really happen.

toiletduckuk
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Post by toiletduckuk » Sun May 16, 2004 11:39 am

Here comes the dumb Q - what powers the LEDs?
Can you post pics of how it sits on your sink? I really gotta duct my CPU, 7v operation doesnt even keep temps stable, nevermind cool - I really regret getting my prescott now :(

josephclemente
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Post by josephclemente » Sun May 16, 2004 5:46 pm

The two LED lights are from Fry's Electronics. I think the brand name was "Lazer LEDs" or something. They have a molex connecter, and each LED has it's own mounting plastic. I just mounted them below the PSU frame area.

Originally, I used a 6" cold cathode, but the inverter caused my PSU to reboot or freeze up the computer. The LEDs are much friendlier.

Reversing the fan is still interesting... To reverse the fan, I'd probably use a strip of metal that starts at the base (where the fan normally mounts) and wraps around to the other side and the fan would mount there. The top part of this bracket would be open so airflow won't be blocked too much, plus I'd still be able to reach the screws which mount the heatsink. I might try it one of these days if I find some aluminum lying around, but my drive to do it is pretty low since it works so well in it's current form.

intx
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Post by intx » Sun May 16, 2004 9:00 pm

[quote="josephclemente"]The CPU fan is blowing down onto the heatsink.

Originally, I was planning on somehow modding the CPU fan to pull air out of the case. This made sense, because it would prevent heating the case with CPU air. I knew from experience with my Shuttle XPC (small formfactor case) that exhausting the CPU air was way better than pulling CPU air in.
quote]

How were you planning on modding it to pull air out of the case? For my setup, it would work a lot better if I could do that, but I have no clue on how.

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Post by ChucuSCAD » Sun May 16, 2004 9:36 pm

Very nice clean looking mod.

jonasy
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Post by jonasy » Wed May 19, 2004 2:19 am

Have to agree with the rest of you,

Awsome work !

Leto
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Post by Leto » Mon May 24, 2004 2:28 am

Could we get a picture of the inside of the case ?

Leto
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Post by Leto » Wed May 26, 2004 10:28 am

Another thing!

Will a duct in an Antec Sonata work? I'm asking this because it looks like the clicking mechanism is right on top of the HSF...

And how do you determine where to put the hole for the duct, I mean u cant really see through the panel so how on earth do you know where the right spot is ?

josephclemente
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Post by josephclemente » Wed May 26, 2004 6:43 pm

Leto wrote:And how do you determine where to put the hole for the duct, I mean u cant really see through the panel so how on earth do you know where the right spot is ?
I used chapstick.

I placed some thin, double sided tape (fiberglass reinforced carpet tape, strong stuff) on the back. Then, I stuck it to the center of the fan's hub. I rotated the fan and made sure the chapstick was centered. I extended the chapstick just enough so that it wouldn't touch the case when I put the panel back on. Once the panel is on, I just flexed it in very lightly to touch the chapstick, making my center mark. Hint: if you have to push hard before it touches, extend the chapstick some more. Otherwise the mark will be too low, because the case won't be flexed in like that when the duct is installed.

Once I knew where my center was, I just marked the circle and cut it out with a simple Nibbler from Radio Shack.

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Post by dasman » Thu May 27, 2004 7:05 am

Joseph,

Just thought I thank you for your mod idea -- I finished it last weekend in my BQE (I got a black mesh cup from Staples) and it took my temps from 55 down to 34 on my P4 3.06 (full load, running fans @ ~11v).

Of course, now I run my fans at 5v and my system is dead silent with full load temps in the mid 40's.

I wish I had thought of the chapstick method -- I held a plumb bob centered over the fan hub, measured and went at it with tin snips. Your way would have been a little easier...

Dave

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Post by josephclemente » Tue Jun 01, 2004 8:25 pm

Great to hear!

Update:

I have changed my P4 2.53GHz CPU for a P4 3.0 GHz (3.0C) processor. Amazingly, all temperatures are reported and behave exactly the same as for the 2.53GHz processor. Temperature-wise, I wouldn't know there was a different CPU installed.

The hyperthreading is cool - now I see what everyone was talking about when the computer responds very well during heavier multitasking. :)

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Post by Edward Ng » Fri Jun 04, 2004 6:31 pm

Yeah HT is da' bomb when U're flippin' back, forth and all about between Indesign, Illustrator, Photoshop and FrontPage...

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Post by dasman » Sun Jun 06, 2004 5:02 am

josephclemente wrote:The hyperthreading is cool - now I see what everyone was talking about when the computer responds very well during heavier multitasking. :)
That's why I switched from a 2.4b (oc'd to 2.8 ) to a 3.06 (w/ HT). Not much difference in clockspeed, but big difference in system response.

Dave

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Post by silencio » Wed Jun 16, 2004 11:46 pm


Bistro
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Post by Bistro » Thu Jun 17, 2004 5:31 am

Really cool-looking mod! However....I am concerned about dust. If there were some way to filter that air, yet still be able to keep that cool blue effect, I would be shopping for the materials tonight.

Maybe I missed something, but what did you use to line the hole in that side panel? Looks like silver car door lining....(?) How did you actually attach the unit? Inquiring minds want to copy....er....know.


Edit: Maybe if I read it more carefully....I see that silver portion is the trim ring of the cup...but is it tight? Did you just wedge it into the side panel hole or did you have to glue portions of it to keep it on?

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Post by dasman » Thu Jun 17, 2004 7:08 am

Nope, I hadn't seen that -- but the text in that first link is a little confusing and appears to suggest that the CPU can be cooled passively!
A thermally advantaged chassis can be recognized by a hollow tube attached to the side panel called a chassis air guide which has flared ends. This tube will funnel cool air towards the processor passively, without fans
Not likely (at least, not for the 90n P4's they refer to). The 12MB video (what a waste of bandwidth, could be 3-4mb easy), shows that the HSF is still required.

Dave

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Post by josephclemente » Thu Jun 17, 2004 7:47 pm

Bistro wrote:I see that silver portion is the trim ring of the cup...but is it tight? Did you just wedge it into the side panel hole or did you have to glue portions of it to keep it on?
Yes, the cup is held in very tight - no glue is needed.

Here is the trick: the cup's trim ring (as seen on the outside of the case) prevents the cup from falling in. Another flange was made on the other side of the cup - after cutting out the cup bottom, the metal on this end was bent outwards. The clear plastic (cut to size from CDR packaging) goes between this flange and the casepanel - this is what prevents the duct from falling out.

Like a puzzle, it holds itself together very securely.

I'm sure some kind of thin filter material could be used, maybe wrapped around the inside on the flange. So far I don't see any increase in dust...

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