# Air intake and exhaust question.



## macbeth (Jun 6, 2006)

My casing has a 120 mm fan in front for intake and 120mm fan at the back for exhaust. I am planing to buy a new power suply with those 120mm sillent fan. So my question is if the air flow in a pc is not equal will it be a problem? Meaning if the casing is taking in more air than its exhausting or the other way round. So given a choice which is better? Equal air flow, more intake or more exhaust.


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## markkleb (Jun 6, 2006)

what case do you have?


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## Juggernaut1987 (Jun 6, 2006)

macbeth said:
			
		

> My casing has a 120 mm fan in front for intake and 120mm fan at the back for exhaust. I am planing to buy a new power suply with those 120mm sillent fan. So my question is if the air flow in a pc is not equal will it be a problem? Meaning if the casing is taking in more air than its exhausting or the other way round. So given a choice which is better? Equal air flow, more intake or more exhaust.



Some people say its better to have more intake then exhaust. There will be a "overpressure" inside the case which is said to keep dust out. Dunno if its true tough but it sounds very likely. Iself have a more or less equal air balance because there are no holes to put extra fans in the front.


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## wtf8269 (Jun 6, 2006)

Equalizing flow isn't all that important. Besides that, most PSU fans don't do much more than 1000rpm.


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## drade (Jun 7, 2006)

Airflow can be important in some cases, like mine, i got only one intake fan in the front (other then psu), then one blowing air out, then 2 blowing air up out of the case, since heat rises. I really think it depends on what setup your having..


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## Azn Tr14dZ (Jun 7, 2006)

I have one 120mm fan intaking in the front, one 80mm fan intaking on the side, and one 120mm exhaustong from the rear. I might make a blowhole on the top soon so I have another exhaust.


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## blacktruckryder (Jun 7, 2006)

I have a Chieftec Dragon and have 1 120mm intake on the side blowing over the chipset and the vid card. Then i have 1 80mm blowhole in the top ( soon to be 92mm or 120mm). With that setup i get case temps that idle at 30c and hit 35c under full load.


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## wtf8269 (Jun 7, 2006)

drade said:
			
		

> Airflow can be important in some cases, like mine, i got only one intake fan in the front (other then psu), then one blowing air out, then 2 blowing air up out of the case, since heat rises. I really think it depends on what setup your having..


Oh airflow is absolutely important, but equalizing the flow so there's not a posative or negative pressure inside isn't that important.


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## dze (Jun 17, 2006)

from my experience u can fry a psu by having too much exaust..it renders the psu flow stagnant or reversed. positive pressure and massive airflow work best on hot machines imo.


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## T4 GTR (Jun 17, 2006)

In the worst case the buildup of pressure would conflict the intake fan but if you was concerned about this just put in a second exhaust fan. The way my case deals with this is there are exhaust vents on the front and the right hand side case panel. You could always put extra fans in the case especially if you are overclocking.


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## T4 GTR (Jun 17, 2006)

Azn Tr14dZ said:
			
		

> I have one 120mm fan intaking in the front, one 80mm fan intaking on the side, and one 120mm exhaustong from the rear. I might make a blowhole on the top soon so I have another exhaust.



I have 2 120mm intake fans and 3 120mm exhaust fans because at work we did an experiment and it seemed that you need more fans on the exhaust side because of the pressure expansion by 15%. It was always better to have more exhaust fans when overclocking if you didn't havee a water cooling kit on the processor.


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## BigD6997 (Jun 18, 2006)

i have a 120mm fan blowing over my hds, then that air goes straight threw to the psu (lian li v1000), but in my top section were the mobo and stuff is, i have a 120mm blowing in to the cpu, then 2 80mm fans blowing in to the grafx card 1 120mm blowhole on top, and a 120 mm exaust in back.... i think i have ok airflow


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## Alec§taar (Jun 18, 2006)

*A tune for you all, perhaps?*

"Breathe..."

by FABULOUS



(That's all you've gotta make happen, to make them do better (just like cars & on BOTH ends, intake & exhaust!))

APK

P.S.=> Humor folks, all this post was about (rest is common sense & just preaching to the choir here largely imo): BUT, the tune applies & is 1/2 decent as well imo & I'm NOT a "rap" fan either... apk


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## Ketxxx (Jun 18, 2006)

macbeth said:
			
		

> My casing has a 120 mm fan in front for intake and 120mm fan at the back for exhaust. I am planing to buy a new power suply with those 120mm sillent fan. So my question is if the air flow in a pc is not equal will it be a problem? Meaning if the casing is taking in more air than its exhausting or the other way round. So given a choice which is better? Equal air flow, more intake or more exhaust.



Balanced is the key, IE, 120mm exhaust @ 80CFM and a 120mm intake @ 80CFM. PSUs that use 120mm silent fans are also prone to causing a "heat spot" in the system as air is directed upward into the unit with no real means of escape, thus, when the system is all together feeling the top of the case where the PSU is you will notice it getting warm, probably quite warm to. Investing in a PSU that uses the "pull-push" airflow method will avoid this. One PSU that uses this method is the Mushkin unit.


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## rpg711 (Jul 4, 2006)

Ketxxx said:
			
		

> One PSU that uses this method is the Mushkin unit.


*cough*says the person that is mushkin tech rep*cough cough*
but dont be convinced by him that the mushkin is the _only_  unit lol


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