Fan blowing direction?

PohTayToez

Active Member
I would say that you would only have Fan 1 as intake, like Mitch said, creating a nice airflow from the front of the case to the back. Fan 6 should always be outtake, so that it expels hot air coming off of the CPU and GPU. I would also say that 4 should be outtake. Having it blowing in would mean that the air would come and hit the hot part of the motherboard on the other side of the CPU, but then the air would have no where to go. Making it outtake would create a current coming from the edges of the motherboard and exhausting the hot air from the other side of the CPU.
 

Stildawn

New Member
So the stock 120mm side fan (fan 6) as a exhust? I would have thought to have it as a intake? Its more to the front of the case than the back?
 

Mitch?

banned

Green for intake, Gold for exhaust. I also drew you a pretty sweet PSU, which will be exhaust no matter what, if the fan faces the ground it'll take most from outside the case anyway, if you get it to face up (which i'd try, it's way more functional and prettier) then it'll also help take any heat away from the generally >80*C videocard.

You also have a spot for an optional bottom mounted 120mm fan. If you choose to install it, have it as intake. Without a fan, the vacuum effect created by the negative draw of your exhaust fans will take alot of air from this hole anyway, so a fan isn't necessary at all.

The side mounted fan is about 4/5th to the back of your case, and vertically centered, and should be exhaust, primarily for the videocard.

So it's:
1,2, possible bottom 120mm fan = Intake
3,4,5,6,PSU = Exhaust
 
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Stildawn

New Member
And what about fan 4 lol.

Man this stuff is complex, way more than I imagined. lol..

Do you happen to know the airflow direction of a V8? Cause wont your diagram above only work if the V8 fan is blowing towards the back?
 

Mitch?

banned
sorry. 4 is exhaust also. edited my post to state that just now :)
and the V8 will either blow to the back or the top, either way, the fan layout i have will work.
I'm PRETTY sure (>95%) that it blows to the rear though.
 

Stildawn

New Member


If its this way, depending on the fan direction will blow either forward or front. If it blows front will ruin airflow hard out.

I might do some more research on it surely it must say somewhere.
 

PohTayToez

Active Member
In reference to Mitch's diagram, I would say that having Fan 3 and Fan 4 blowing different directions would be a bad idea, and most likely just waist air flow.
 

Stildawn

New Member
I think the idea of fans 2 and 3 being opposite is to cycle the air through my Cooler Master V8 which will draw the "cool" air coming in from fan 2, use it and then fan 3 will get rid of the hot air.
 

Ramodkk

VIP Member
W=(1/2)mv^2 is the work produced by the fan. It makes sense that the mass of the air moved by the fan times the velocity of that air equals the work of the fan. It is simply the amount of air moved multiplied by how fast it is moved.

P=((1/2)(mv^2))/t is the power consumed by the fan during operation. Basically the amount of work done by the fan on the air divided by the amount of time the fan has done the work will equal the amount of power the fan consumes. This also implies that you can find how much work the fan produces if you multiply the power it consumes by how long it consumes.

A=D^2/1974 is simply the outlet area of the fan set equal to the diameter of the fan blade squared divided by 1974. This equation by itself is not important but it helps you find terminal velocity which is important.

V=.932(cfm/D^2) is the terminal velocity equation. Terminal velocity being when the fan has reached its max push/pull at which the air is no longer accelerating. This equation multiplied by 1/2 of 1 cfm equals the power consumed by the fan. Think of this as the terminal velocity (max output of the fan) has a direct relation to how much power is consumed by the fan.

Simple mathematics...
Or, you could flip the fan :p

The best setup would be:
Rear Top Fan Out, Front Top Fan In (in front of CPU)
Rear Fan Out
Side Fan Out (videocard will need to be exhausted, trust me :p)
PSU Fan Out
Front Fan In
Behind-Mobo Fan Out
It'll create a pseudovacuum, but the negative pressure will be okay because it'll bring more hot air out than bringing in more room temp air, and will also make the 80mm mobo fan more effective.
Best setup is simple. 1 x 120mm intake and 1 x 120mm outtake ;)
 

Stildawn

New Member
So I just found out much to my disgust that my 80mm x 25mm case fan can not fit in the behind mobo position as its too large (needs to be 15mm)

So Im left with a rather expensive 80mm fan.

What would you guys do? Is there away to front mount it in the CM690 to help out the front fan?

Cheers


Fan 4.
 

Stildawn

New Member
Lol like underneath it?

I could mount it in the bottom slot near the front. Using cable ties or something.
 
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