Air pressure inside case

[pirate252]

First just to clarify myself about the air pressure...By positive air pressure i mean blowing more air into the case than is blowing out (EX/ 2 fans in and 1 fan out) or by negitive air pressure, i mean blow more air out than in (EX/ 2 fans in, 3 fans out)

My question is...i am buying a case that has 2 80mm in front (in) and 1 80mm in back (out) so there will be a positive air pressure in the case and i am wondering if that is a better configuration than if i punched out some more holes and created a negitive air pressure (put in 2 more fans to make it 2 fans in and 3 fans out. So i just want to know what would be a better configuration for the cases cooling, positive or negitive air pressure with the fans.

Thanks alot,

Matt

 

[salmonsteak]

I would go with the initial configuration. It should satisfy the minimum amount of air pressure required to keep the interior of the box from getting to hot.

Now if you are an overclocker... then I may go with the second configuration, as the chip is going to yeild a higher ratio of heat, but of course that all hinges on how far you push the chip.

 

[ceh4702]

I think the best way to cool the motherboard is by sucking the air directly up and out right off of the cooling device and CPU to send the hot air out of the case. However, other things make heat also. Hard Drives and CD drives can account for quite a bit of heat. It would not be uncommon to have a CPU running near 150 deg F and to have a case temp at 90 deg F. This has got to be bad for the Hard Drives and CDROMS. This has got me to thinking the compartments for the drives and motherboard should be sealed off and seperated. I never have liked case configurations like they are today for the ATX Standard. If you do not like my post feel free to point out your opinion or my errors.

 

[paparazi]

Are you forgetting the power supply fan? which is also exhausting out.
Two in, two out, sounds good to me.
Anyway it is the CFM figures (the actual amount of air the fan shifts)that count, and it is possible to have a two/one split with neutral air pressure if the one fan is a more powerful (higher CFM) and equivellant to the two fans combined.
Take it from me, a slight differance either way ain't gonna make a jot of differance.
But nice to see someone actually taking case cooling seriously. Martin Just trying to help, sometimes falling short, I am only human after all.

 

[pirate252]

Yeah thanks, i am already using my computer for things like ripping DVD's and i know that creates extra heat, and i am buying all new case, heatsink etc, stc. because i am interested in experimenting with overclocking so thats the 2 reasons why i am interested in its cooling, but thanks for the post, helpes point some things out that i wanst thinking of before.

Matt

 

[cdogg]

While you're at it, why not do some case modding in the process? Besides having a lot of tips and ideas for cooling, some of these sites can also show you how to completely change the look of your boring beige box.

If you've got the time, it may be worth it:

http://www.casemodworld.com/

http://www.modthebox.com/

http://www.overclockercafe.com/

http://www.extremeoverclocking.com/

 

[JonathanB]

Just to add, place an aircon filter to your intake fans. This will keep your PC interior clean from dust. This will also balance your airflow, if ever you have two intake and one exhaust.

 

[hotfusion]

My 2 pence worth:
Go for positive case pressure. The reasoning behind this is that if all the air is extracted via the PSU, this component will run hot as a result of internal warm air being used to cool it.
If the case is pressurised, the extra air is vented via the perforations, leading to a cooler interior and a cooler PSU.
My suggestions are what I would try myself. If incorrect, I welcome corrections to my rather limited knowledge. Andy.

 

[cdogg]

hotfusion makes an excellent point that we should really pay close attention to:

"extra air is vented via perforations"

You can never really have + and - differences in air pressure since the case is not truly sealed. Like paparazi said, it isn't going to make a whole lotta difference either way. If you must go one way or the other, having more air intake is probably the better choice. The circulation of air across the CPU and mobo will be slightly greater.

I would stick with 2 fans on the front and cut a hole for a fan in the top of the case (blowhole). Since heat rises, this will allow excess heat that isn't being pulled by the "wind-tunnnel effect" to escape easily.