View Full Version : ducting experiments continued

01-13-2001, 02:00 AM
I made a few "improvedments to my duct, mainly trying to get more airflow through the heatsink... but not so great performance..

Firstly I changed it so that I could have two 80mm fans side by side blowing onto the heatsink. temperatyres were the same or highr than original duct. Then i thought that if i force fed the air sideways through the fins using only 1 80mm fan it would cool them better. disastrous results. So I thought perhaps there was not enough air blowing through. and I did not have enough space to add a 80mm fan. So I created the mega duct: 0ne 120mm monster forcing air through the fins and out the other side. the result: incredible noise at 12V, and rapidly climbing temps at 5V... argh!

My guess is that the design of the heatsink itself (it has fins placed at 90 degrees to the clip, in other words aiming straight at the motherboard when placed on slotket), and this creates too much air resistance at the exit, and thus the air is forced to go back up the duct and out around the edges of the fans. Terrible...

Anyway I'm going to try sealing the edges of the fan and easing the exhaust of the air... but if anyone has any suggestions, they are always welcome.

02-21-2001, 06:03 PM
I do have a few suggestions http://www.procooling.com/ubb/smile.gif
I dabble in ducting cold air into my case from outside. The air outside is around zero celcius and i use two window fans with some 4" aluminum tubing with some duct tape. The two tubes outputs are connected directly to my cases two intake fans. both 80 mm.
Now, this is revision #2....#1 had the first tube connected directly to the hsf, so the only air that cooled the cpu was from outside...i achieved 17C...drool...and improved my oc'ing from 1365 to 1.45G with a 1.2Tbird. It actually posted at 1509 http://www.procooling.com/ubb/smile.gif
I had the second tube aimed into the case to cool the motherboard and video card. The mobo temp got down to 7C
Well...below 15C or so, i'd start worrying about condensation.
Since i'm planning on building a watercooling peltier rig next month, i'm just screwing around with the air cooling once again. If i toast this cpu, its a good excuse to buy a palamino in a few months...cackle.

1.2Tbird @1352 air cooled. Soon to be watercooled :P

02-21-2001, 07:41 PM
Ok, i have my two ducts hooked back up.
Its -5C outside.
I'm running my 1.2Tbird at 1.43 Gigs...my cpu temp is 22C and mobo temp is 16C
I got a window's registry error before when tryign to go to 1.44....but my temps were 26C then...might try to go up here in a little bit.
As far as stability....prime95 fails, but the comp doesn't crash or anything. 3dmark2000 will run....scores 10500 at the 640x480x16 mode. I'm using a geforce2 gts at 215/255 currently. (can't wait to get a geforce3 :P)

1.2Tbird @1352 air cooled. Soon to be watercooled :P

02-28-2001, 12:13 AM
What do you guys do to make sure you don't get condensation?

02-28-2001, 12:04 PM
phf. . .condensation shamtion. . .just move to idaho where the humidity factor stays around 0-1%, do you have any idea how tough it is trying to get condesation to occur with that low humidity in the middle of a snowy winter day?!? only prob with the dry air is that your skin dries out like nothing and your lips are always chapped and this and that. . .

well anyway, post pics I wanna see this ducting http://www.procooling.com/ubb/wink.gif

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Leo Hoodak
03-21-2001, 12:02 PM
I took a similar approach, but not quite as drastic. I went to the hardware store and bought some flexible dryer exaust duct. Spiral wire covered in plastic. I duct taped it to the exaust side of an 80mm case fan. It twists and turns easily although I had to flatten it out (easily done due to the flexibility of the wire) to get it through the space between the hard drive bays and the main board mounting plate. Twisted it and straptied it place so that it points right at the hsf, which has been partially obscured by the position of the memory stick. I then added a fan to exaust the air coming out of the cpu cooler.

Leo Hoodak
04-01-2001, 09:32 AM
I got rid of the ductwork. The best cooling results I have found was to ensure full airflow through the cabinet. I got a pair of square nippers at Radio Shack, and completely got rid of all the sheet metal holes and slots in front of (and behind) the fans for the case. I got rid of my 3rd 80mm fan, and just used 1 in the front and 1 in the back (exaust). The placement of the the rear fan I believe to be of more importance in this cabinet. It's position is directly behind the cpu cooler, Alpha PEP66, by about 3 inches. The 50cfm exaust fan I believe pulls more cool air over the intake of the Alpha, and I am seeing now sustained average of 43c, where before I eliminated the sheetmetal, my average was 55c. Slightly o/c the 1ghz Intel cpu to 1109mhz, the temp hasn't climbed in 24hrs running Seti@home and cpu stability test concurrently.