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Posted: Tue Jun 04, 2002 6:13 pm Post subject:

I don't know if anyone said this already but figured I'd chip in my thoughts on fan positioning.

The rear fans that are up higher should be positioned so that it blows air OUT of your case. The front fans should be positioned so that it sucks are IN to your case. We all know hot air raises, so if you have the rear uppper fans blowing air over your heatsink, you may be bringing cool air in to cool your heatsink, but you're also pushing the hot air deeper into your case. So by sucking hot air out where it's most dense (the upper region of your case) it'll be displaced by cool air from below which comes in from the front. That cool air warms up, raise to the top of your case and gets sucked out.

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Finally got this image to display my SETI stats. Took me bloody long enough. Thanks for the help guys! LWD rulez!

Posted: Tue Jun 04, 2002 10:09 pm Post subject:

Thanks Lycander for pointing this out again. I already had the fans assembled so that the fronts suck air in and the backs blow air out of the system.

Most people do not know how to behave in a massacre.

Big Dog Joined: 20 Oct 2000 Posts: 3689 Location: USA

S.O.S.

did you get your card cooler installed yet ?

and if so, how many degrees did it shave off of your GeForce ?

Posted: Wed Jun 05, 2002 9:40 am Post subject:

I came to the conclusion that in addition to filtering all inbound air on a case you should have about 3-5 cfm of positive air. The reasoning is that if you have say 60 cfm from your fans blowing in (reduce cfm by about 30% when using filters) you need to exhaust about 55 cfm (make sure you count the PSU fan) the rest will escape from the case at the seams and though those annoying little holes they insist on drilling in your case at the factory in an attempt to make you think it is well ventilated. This will keep your system cooler longer as the efficiency of a heat sink diminishes quickly when it is choked in dust and tar (My roommate and I both smoke 2 packs a day). I had to take a class in maintaining air circulation in enclosed spaces while I was still a painter. Never thought that would come in handy.

I have had good luck with really 120mm fans for intake with foam filters. I usually use the same number of 80mm fans for exhaust. They seem to ballance well.

Posted: Wed Jun 05, 2002 9:55 am Post subject:

Quote:

S.O.S.

did you get your card cooler installed yet ?

and if so, how many degrees did it shave off of your GeForce ?

What would Jay and Silent Bob do :

Not yet I'm still hunting one that will fit between my GF4 and the CPU, also I dont have a slot above the GF.

Maybe I go use that old 40mm fan on the backside...

Most people do not know how to behave in a massacre.

EEps · Posted: Wed Jun 05, 2002 12:10 pm Post subject:

I've been doing some research over at Overclockers under their Case Cooling section and some of the posters there dedicated a duct for their CPU fan.

I've also been wondering how well the AOC system blower works. It's rated for 42 CFM and I know that blowers work more efficiently than fans. I'm thinking about modding my case with these and dedicating 3 of them for my CPU. Will be making a specialized bracket to hang 2 of them over my CPU heatsink and 1 over the top of the heatsink to exhaust the heat out of the side of the case. Maybe some ducting to ensure it gets it's own airflow without contaminating the air in the case.

Here's also a crazy rant... How come video card manufacturers didn't make their GPU to go on the other side of the card...especially for the AGP slot?!! It would make total sense as heat rises and there usually isn't anything on the other side of the AGP slot...

BamZipPow
...how things get done

Big Dog Joined: 20 Oct 2000 Posts: 3689 Location: USA

Quote:
Not yet I'm still hunting one that will fit between my GF4 and the CPU, also I dont have a slot above the GF.

you don't want it between the gf and the cpu, you want it in the top pci slot pulling the exhaust directly off of the hsf on the video card

Posted: Wed Jun 05, 2002 4:00 pm Post subject:

me thinks satan of seti has never built a computer before......oh well, we all start somewhere

Till animal control gets called

INSUFFICIENT KNOWLEDGE

Posted: Wed Jun 05, 2002 5:36 pm Post subject:

Oh man, SOS you have been slammed by a teenager...

Nothing but net..

WOOF!

PLD
"I wonder what goes through his mind when he sees us peeing in his water bowl." -Penny Ward Moser paw5

Posted: Wed Jun 05, 2002 5:53 pm Post subject:

Quote:
I know that blowers work more efficiently than fans.

Centrifugal blowers work better against more pressure than axial flow fans do, but in the free-air case with little or no differential pressure, an axial flow fan can be more efficient than a centrifugal blower.

Quote:
Here's also a crazy rant... How come video card manufacturers didn't make their GPU to go on the other side of the card...especially for the AGP slot?!!

ftp://download.intel.com/technology/agp/downloads/agp20.pdf

Chapter 5 is the mechanical specification (beginning on page 209). Figure 5-1B on page 211 shows the maximum allowable dimensions of an AGP video card. Note 2 says that "Solder side max component height is 2.667mm (0.105in)." Note 3 says that "Component side max component height is 14.47mm (0.570in)." The solder side is oriented toward the CPU, while the component side faces the PCI slots.

Finding a GPU that would be less than 2.667mm tall might be possible if you went with chip-on-board packaging, but a paper-thin heatsink would be a pretty tough trick. Of course, as you pointed out, most motherboards have plenty of room on that side of the AGP slot, so you don't usually run into a problem installing aftermarket heatsinks like the ones that come in this kit: http://www.thermaltake.com/products/chipset/g4.htm

Notice that the heatsink and fan are only 12.8mm thick.

:pawa1:

Posted: Wed Jun 05, 2002 6:05 pm Post subject:

Quote:
did you get your card cooler installed yet?

http://www.thecardcooler.com/shopcart/CardCoolers/CCXT_specs.html

I have one of these monsters, but I don't use it. The powerful Sunon 120mm fans actually provide very nice silent cooling when driven by only 7V instead of a full 12V.

I put one of these in the PC that I built for my Dad after I discovered that the el-cheapo ($29 including PS) case that I got did not have enough ventilation for a Duron and a Voodoo5-5500. I also drilled an array of holes in the front panel and added a 92mm front fan and an 80mm exhaust on the back. My brother complains that the blower is too loud.

:pawa1:

Posted: Wed Jun 05, 2002 6:17 pm Post subject:

Quote:

Oh man, SOS you have been slammed by a teenager...

Nothing but net..

WOOF!

PLD
"I wonder what goes through his mind when he sees us peeing in his water bowl." -Penny Ward Moser

WOOF!!! WOOF!!!

Till animal control gets called

INSUFFICIENT KNOWLEDGE

Posted: Wed Jun 05, 2002 10:05 pm Post subject:

Quote:
me thinks satan of seti has never built a computer before......oh well, we all start somewhere

ARRRRRRRRR...

Well kid, back in the days I built my first 286 from scratch. You even know what that is?[ Sticking out Tongue

]

I have built some computers, but never had the heat issue (or at least never bothered).

That case cooler item sure looks great, but.... I would have to mod the side of the case to let out the heat... *ugh, there must be another way*

Most people do not know how to behave in a massacre.

Posted: Wed Jun 05, 2002 11:59 pm Post subject:

286??? i know what a TI-86 and a 486 is......

Till animal control gets called

INSUFFICIENT KNOWLEDGE

Posted: Thu Jun 06, 2002 12:01 am Post subject:

if i had a good digital camera.....i would send you a pic of what i did to my case to lower temps.....lowered cpu 25 degrees and case temp about 10.....and all it is was a $8 piece of plasic

Till animal control gets called

INSUFFICIENT KNOWLEDGE