Case Fan Questions.

[kenderkenobi]

I am building inside a phenom m mATX case. Currently I am using:
2x gentle typhoons 120mm 1450rpm in the top pulling in. (This is how the phenom is meant to draw air so don't tell me to make them exhaust please)
1x h60 with standard 120mm pulling cooler air in from outside.
1x 200mm bitfenix rated for around 150cfm exhausting.

I plan to put filters on the intakes. Which I know will cut down on their cfm for intake.

I'm worried about creating negative or neutral presure in the case.

Can some one lend some insight?

 

[geofelt]

There are two requirements for a positive pressure airflow that keeps your case clean.
1. There should be one source for intake air.
2. The filter should be at the source.

Do not use exhaust fans, or at least, they should be much weaker than the intakes.
If they are too strong, they will draw in unfiltered air from other case openings.
The H60 should suffice as an exhaust fan. It will cool the cpu radiator and help direct the airflow out of the case.
If you use it to draw in cool air from the outside, your cpu will cool better, but it will draw in dust and heat up the insides of the case.
Not good for the motherboard or graphics cooling.

Using the top two 120mm fans as filtered intakes is fine and will work.
But, omit the 200mm exhaust fan. If you use it, it will draw in unfiltered air.
A 200mm fan should have more air moving capability than 2 120mm fans.

You could do some experimenting since you apparently have all the fans.
I would try the 200mm as intake and omit the top fans.
Hot air wants to rise so this seems to make more sense to me.

Sorry, if I told you what you did not want to hear.