Unconventional Case Exhaust

[Awakening]

 

Something that's always bugged me is the consistency, alignment, and symmetry of the CPU/CPU fans and the rear exhaust fans. Using the CPU fans as a rear exhaust fan paired with one up top seems to be an acceptable solution to this, but I'm not sure how well a fan will do getting air through small holes that are an inch or more away from it. These would be the fans used on the heatsink while the case fans would be these.

 

Do you think this scenario will end up having too much positive pressure because the CPU fans won't act well enough exhausting air from the case?

 

 

[NoRomanBatmansAllowed]

3 minutes ago, Awakening said:

 

Something that's always bugged me is the consistency, alignment, and symmetry of the CPU/CPU fans and the rear exhaust fans. Using the CPU fans as a rear exhaust fan paired with one up top seems to be an acceptable solution to this, but I'm not sure how well a fan will do getting air through small holes that are an inch or more away from it. These would be the fans used on the heatsink while the case fans would be these.

 

Do you think this scenario will end up having too much positive pressure because the CPU fans won't act well enough exhausting air from the case?

 

 

The best way to find out would be to test it yourself.

 

Each case is different. That's all I've got to say.

[Awakening]

Just now, bob51zhang said:

The best way to find out would be to test it yourself.

 

Each case is different. That's all I've got to say.

 

I don't have the components or else I would.

[airdeano]

nix the roof fan, it'll destroy the flow path of the air for the HSF. otherwise the best config for the case.

reasoning is that the intake fans are filtered. thus cutting down the amount of air entering the case. show in actual usage you have 1.5 120 in and 1 120 out.

this would be a slight positive pressure and desirable.

[Awakening]

1 minute ago, airdeano said:

nix the roof fan, it'll destroy the flow path of the air for the HSF. otherwise the best config for the case.

reasoning is that the intake fans are filtered. thus cutting down the amount of air entering the case. show in actual usage you have 1.5 120 in and 1 120 out.

this would be a slight positive pressure and desirable.

 

My main concern at that point is air bouncing off the rear of the case instead of going through it because the exhaust fan would be attached to the heatsink instead of the rear of the case.

 

I don't understand how the top exhaust fan will screw up the airflow though. The heatsink has greater static pressure and airflow than the top exhaust fan has so most of the intake air should be going into the heatsink fans and then most of the air coming out the other side of the heatsink should be going through the exhaust fan. Or am I wrong?

[airdeano]

air is lazy and only uses airflow paths created by the fans. so air really won't 'bounce' from the rear i/o as the rear fan will guide it to the exit.

the idea of the HSF is to take air coming in to the front and discharging out the rear. placing a fan directly above will change that flow path and potentially rob from the HSF.

[WoodenMarker]

12 hours ago, airdeano said:

nix the roof fan, it'll destroy the flow path of the air for the HSF. otherwise the best config for the case.

It can help overall temps if the rear fan isn't enough to vent the combined heat from other components like the GPU--depends on the specific configuration. 

Having a similar config with a top exhaust in my Define S results in lower temps with very low rpm noctua fans.