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Everyone on this forum should make a duct, 10*C - 12*C drop!!!

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voodoomelon

Member
Joined
Oct 9, 2001
Location
Dundalk, Ireland
Everyone on this forum should make a duct, 10°C - 12°C drop!!!

The VoodooDuct

I attained a 10°C - 12°C drop!!!

Hey all,
I've been reading for years about the thermal gains others have been getting from installing a duct on their CPU heatsinks, but never actually did it myself. -> I thought €15 for a duct for a mere 1°C - 3°C reduction wasn't worth it.

What I was tring to do was eliminate the "dead spot" created by the hub of the CPU fan, on my SLK-900u heatsink. You can clearly see here the center of the heatsink that is untarnished due to lack of airflow:

Dead_Spot.jpg

So, I got a cut-off piece of perspex that i had left over from my window, and cut out 4 little pieces of 80mm X 35mm.
This is because my Tornado fan is 80mm X 38mm. The 3mm difference is so that I could still use the clips that came with my SLK 900.

I then simply glued them in a box shape, with 2 of the sides sloped.
I have since placed masking tape on the edges to eliminate vibrations and sprayed it with silver paint.

Duct1.jpg

duct12345.jpg

duct123.jpg

That's it!! All I did then was snip off the "wire bar" that connects either side of the 2 clips so they would fit, and then placed the duct on the SLK-900u with the Tornado on top.

I booted up this morning, and the CPU temp was stable at 21°C idle, it was usually ~34°C. Unbelievable! And my Toranado is only running at 5v, not even half its normal speed.

Anyone can make one, from cardboard, wood, plastic, perspex - anything. And they should!

This mod works best with a Tornado 80mm or 92mm fan and any recent Thermalright heatsink, as the design of the Tornado means that air swirls down the center of the duct into the heatsink. The duct is designed to fit an SLK-900u, ie, with the sloped sides parallel to the sides of the heatsink. You should see at the very least a 5-6 degree drop.

However EVERYONE should try this mod, and you should see at least a 2-3 degree drop, with any fan, as long as you have the sloped sides parallel to the sides of your particular heatsink.

Give it a try, and post before and after results!

:D
 
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deathman20

High Speed Premium Senior
Joined
Aug 5, 2002
Yea case temps would have a major affect on this. Besides how cold is your room then too?? Not everyone will even see close to that drop in temps unless there venting in some outside air or something in the winter :)
 

DayUSeX

Member
Joined
Aug 13, 2003
nice what is your ambient temp?? ducts are cool im trying to figure out how to sequeeze one in my SFF, but excellent drop
 

nodark

Member
Joined
Jul 17, 2003
Location
Harlingen, Tx.
After seeing your results, I guess I'll have to give the duct idea another shot. I had tried making one for a 120mm fan for my 800U heatsink and the results were no different with or without a duct.
 

Sniper_83

Member
Joined
Aug 30, 2002
Location
Wisconsin
Nice temps, I'm looking for ways to lower my temps. Though in my case ducting for the CPU is almost worthless. I have to keep the case temps low in order to lower the CPU temp.
 
OP
voodoomelon

voodoomelon

Member
Joined
Oct 9, 2001
Location
Dundalk, Ireland
Okay, wait...
I must retract my original claim -> after a bit of testing, CPU idle is now 24*C, and my case temp is exactley 22.6*C at the moment.

My room temp is usually about 19*C, the ideal room temperature. I tend to keep it like that by opening the window for a minute every half hour or so -> its about 0 - 1*C outside now.
I still have to do a bit of load testing though.
And now, for some lovely(ish) pics...:D

Top.jpg


Side.jpg


SideBottom.jpg



Not everyone will even see close to that drop in temps unless there venting in some outside air or something in the winter

I know, these temps are very much dependant on my setup, but that's what I got. But basically what i mean to say is that if anyone else ducted, they would see at the very least, a 3*C drop, because of this -> http://www.ocforums.com/vb/showthread.php?s=&threadid=248951&highlight=dead+zone

I urge everyone to give it a go, just grab some cardboard!!
;)
 

Sniper_83

Member
Joined
Aug 30, 2002
Location
Wisconsin
You know why your temps droped!

Well by looking at your picture, it appears that your design is eliminating your dead zone which is created by the fan hub. Now the air is hiting the whole HS.
 

deathman20

High Speed Premium Senior
Joined
Aug 5, 2002
Well taking a look at that picture isn't that considered a fan hub? Thought ducts linked the CPU air right to the outside of the case. Either way I want to try this sometime when I can have my main rig down to test stuff out.
 

Sniper_83

Member
Joined
Aug 30, 2002
Location
Wisconsin
Yea it looks great, Thermaltake (I think thats how its spelled) was the first that I know of to make a duct similar to that. They have a semi curved duct with a fan on the outside moveing the air into the HS. I'll see if I can find that link.
 

Jognt

All round good guy
Joined
Aug 24, 2003
Location
Netherlands
lol!

its pretty funny how that ductingmod site from TT is commercialing (or something) their other TT parts :D
 

EmAzY

Registered
Joined
Nov 12, 2003
Location
Vancouver *604*
good idea... but i think it would be better if u have like a sunbeam overclocking ducting kit or custom similar to it... which has a hose duct from outsidt to inside of cpu... so direct outside cold air will go directly to the cpu, in instance with this setup case temp dont matter coz the air is coming directly outside...

i dunno, what u guys think :)
 
OP
voodoomelon

voodoomelon

Member
Joined
Oct 9, 2001
Location
Dundalk, Ireland
Yeah, i'd have a duct that lead all the way up to the case door if the door handle wasn't in the way. -> attached.
But it wouldn't look nice, and i'll be damned if i put a big ugly ducting hose leading to a front intake across my lovely new window. Ahh!

:cool:
 

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Dragonprince

Member
Joined
Dec 4, 2002
Location
CT
I would think running the duct out the side window/panel of the case would give the best results for CPU cooling. The primary reason most people have heat issues is blowing hot case air on the CPU. I dont see how just raising the fan a couple inches off the CPU would make a huge difference since the air is the same. I wonder if the % increase in cooling efficency equals the additional % of heatsink surface thats no longer in the fans dead spot.
 

Sniper_83

Member
Joined
Aug 30, 2002
Location
Wisconsin
Well I'm not sure what you just said but I know that if you have air movement over the whole HS it will cool more efficently than when it has a large spot over the core that is not cooled.