overcooling project - airtube from front fan to CPU cooler

[warrior]

Hey everybody

I've got a question that you hard-core overclockers may know the answer to;
These are my specs:
Athlon T-bird 800 @ 1 gHz ( 100mHzx10)
ASUS A7V
256 MB 100 mHz DIMMS CAS/RAS2
Case with 1 power transfo fan
2 case fans on the rear blowing air out
1 fan on the front blowing air in
Cooler Master CPU cooler fan
cooling paste between the CPU and grid ( not too much)

I had this problem:
standard CPU temp in idle with ASUSprob read
CPU @52°C
Mainboard at 32°C

This was no problem to keep the system stable.
However, whenever I'd run a CPU intensive application , CPU temp 'd go up to 57°C which appearantly is crash temp. for this CPU.

Now i'm not into watercooling ( I don't know a thing about it and I don't wanna either) but I thought;
what use is there in having any cooler blow air onto the CPU cooler if the air itself is hot? So, if I could get the CPU to blow in cooler air from outside the case straight onto the CPU grid, it should cool things down, right?
Wrong, it seems.
I have placed a plastic tube in the case from the front to the CPU. On the front, it is placed on the fan that blows air into the tube ( completely sealed so that it takes in only outside air and that it goes into the tube alone.)
Then it runs to the CPU where the cooler master fan again blows the air from the tube ( and only the tube) to the cooler grid.
However, to my astonishement, the CPU now reads
54°C with ASUS probe
and mainboard 34°C.

I don't get it, any ideas on what may be wrong with it?
Would blowing air OUT increase usefulness? ( so invert both CPU and case fans)?
Below is a photo of it ( or a link if this fails)
or

http://www.primocom.com/TAW/cooltube1.JPG

 

[dgk]

That's cute. I can't see whether the duct is actually covering the CPU area but it looks like it is. I'd guess that anything that interferes with moving air away from the CPU would be bad. If that duct is covering the heatsink and isn't providing freezing air, it is likely doing more harm than good.

 

[warrior]

No, it runs as far as the fan, the grid is completely free so air can escape easily. There's also a lot more air moving over the grid.
Still, it even feels hotter than without the tube. Don' get it

dgk (Feb 08, 2001 11:32 a.m.):
That's cute. I can't see whether the duct is actually covering the CPU area but it looks like it is. I'd guess that anything that interferes with moving air away from the CPU would be bad. If that duct is covering the heatsink and isn't providing freezing air, it is likely doing more harm than good.

 

[heavenly]

Hi i have try'd a simular setup but it didn't work , the hot air that leaves the heatsink is blowing on your mobo , you could try reversing the airflow( hot air from heatsink dumped outside the case. I also have to mention that the Asus Probe is crap!! it will give wrong temps in 99 out of 100 systems Go get Motherboard Monitor 5.04 It gives the best readings.!

 

[walker]

The main thing IMO is this.
1.) you have 2 fans on the back blowing out.
2.) your PS also blows out.
So the only fan that is bringing in any fresh air is the on you have on the front of your case, that is now hooked up to a tube - connected to your CPU.

This would tell me that the only air coming in gets heated up as it passes through your heatsink. therefore making the inside of your case hotter and also your chip.

What I would do is cut a hole in the side of your case and run that tube from it to your chip. (cooling your chip with fresh room temp air. Also this would free up the front case fan to bring in fresh air to the rest of the case.

I have done this to my system and my temp are as follows:
case idle = 20c
chip idle = 25c
chip worked up = 29c - 31c

If you have any question e-mail me [email protected]

 

[stool]

From your profile, I think your problem is the CoolerMaster. I just tried one on my 1g TBird, and it got so hot that in 45 seconds it was locking up. I put a GlobalWin on it and no problem.

 

[warrior]

Problem solved!

I took the front fan away from the front of the case and placed it on the bottom of the case ( so that it simply takes in internal air)
The front fan opening didn't allow sufficient air to get sucked in ( just some small holes.) This decreased airflow to such an amount that not enough air got into the tube.

Now, with the fan on the bottom, I get this reading;
before the tube: 52°C in idle
tube attached to front of case: 54°C
tube fan sitting on the bottom: 45°C
(idle readings)

The solution provided above about too many fans blowing out seems unlikely in any case. The displacement of air getting blow out forced fresh air in through the numerous small openings that exist all around a case. They're not air-tight after all.
Anyway; I'm cool now
Gonna try 1.05 and 1.1 gHz later today, wish me luck