Hi all,
I just received my Coolermaster 201 and am contemplating fan management. It has 4 case fans (rear exhaust, blow-hole exhaust, 2 front intakes, plus PSU). The front intakes are important because they will cool 4 HDs installed in the lower 3.5" bays. Then I was reading about positive/negative pressure.
If I removed the 2 front intake fans wouldn't the 3 exhaust fans pull sufficient air through the front intake holes? Why do the intake fans need to be there at all?
TIA.
Front intake fans really needed?
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powergyoza
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In my experience, I found that the intake fans help very little, it at all. So as long as the intake vents aren't too restrictive you should be fine.
The blowhole is another issue. You've seen jinu117's experiments in this thread. To me, it doesn't seem very useful for ventilating the case, but it could be useful for supplying the PSU with cooler air.
The blowhole is another issue. You've seen jinu117's experiments in this thread. To me, it doesn't seem very useful for ventilating the case, but it could be useful for supplying the PSU with cooler air.
Actually, jinu117's experiments is what got me to thinking. His experience was that negative pressurization occured, which makes sense.
Seems to me:
- Once you install an intake fan and turn it on, you are controlling the amount of air (for the most part) that enters the case.
- Also, with exhaust fans, you are controlling the amount of air that leaves the case.
- Even if you could balance the pressure, if you have some automatic fan controller adjusting the speed of the fan(s), at certain points you will either experience negative or positive pressure, both of which seems like it would effect efficiency.
My thought is to have the rear exhaust and the blow-hole both blowing out and connected to the mobo fan controller. This would result in anywhere between 1-3 fans (including PSU) blowing out at varying speeds. At the same time if you not only disconnected but removed the front intake fans (to eliminate intake resistence) and simply left open holes, as the exhaust fans increased/decreased/etc. the intake (pressurization) would always be equalized. When the case got hot and the exhaust fans were cranked up, the amount of air being brought in (and therefore passing over my HDs) would also increase. In this scenario, I'm not sure where using front intake fans are any better.
If someone could shed some light, I'ld appreciate it.
Seems to me:
- Once you install an intake fan and turn it on, you are controlling the amount of air (for the most part) that enters the case.
- Also, with exhaust fans, you are controlling the amount of air that leaves the case.
- Even if you could balance the pressure, if you have some automatic fan controller adjusting the speed of the fan(s), at certain points you will either experience negative or positive pressure, both of which seems like it would effect efficiency.
My thought is to have the rear exhaust and the blow-hole both blowing out and connected to the mobo fan controller. This would result in anywhere between 1-3 fans (including PSU) blowing out at varying speeds. At the same time if you not only disconnected but removed the front intake fans (to eliminate intake resistence) and simply left open holes, as the exhaust fans increased/decreased/etc. the intake (pressurization) would always be equalized. When the case got hot and the exhaust fans were cranked up, the amount of air being brought in (and therefore passing over my HDs) would also increase. In this scenario, I'm not sure where using front intake fans are any better.
If someone could shed some light, I'ld appreciate it.
There are two seperate issues:
1) Front Intake Fans
2) Positive air pressure
1) Intake fans are placed in areas were you want to ensure active cooling - for example your drives, and possibly your CPU and Video Card.
If you go with all exaust, unless you do a real good job of sealing up your case and directing air flow, the intake air can come from anywhere. This means that you may not be able to ensure adequate cooling in key areas.
2) Positive air pressure is a time-honoured technique to reduce dust in an enclosed space. This is it's only purpose.
It is quite easily achieved by ensuring there are more CFM coming in than going out. Many schemes fail because the designer fails to account for loss of airflow from filters, and forgets about the PSU fan.
At the pressure level of a computer case, there is no purpose in attempting to finely balance air pressure to be just on the positive side.
Here is how I set up my case:
Two Filtered Panaflo L1A intakes in the front, one in the top. Two Panaflo L1A's as exausts - one in the back and one in the PSU.
Why:
Intake 1 - Front Intake blows directly on my hard drive.
Exaust 1 - The PSU needs a fan to adequately cool it
Exaust 2 - Draws air across the CPU
At this point my components are adequately cooled, but I have a dust problem.
Solution - positive air pressure.
I look around and see that I still have two mountings available - in the Front and top, so I put intake fans there.
Result - no dust, and the fringe benefit of overall cooler temperatures.
Downside - a little too loud for my taste, but that's another discussion.
1) Front Intake Fans
2) Positive air pressure
1) Intake fans are placed in areas were you want to ensure active cooling - for example your drives, and possibly your CPU and Video Card.
If you go with all exaust, unless you do a real good job of sealing up your case and directing air flow, the intake air can come from anywhere. This means that you may not be able to ensure adequate cooling in key areas.
2) Positive air pressure is a time-honoured technique to reduce dust in an enclosed space. This is it's only purpose.
It is quite easily achieved by ensuring there are more CFM coming in than going out. Many schemes fail because the designer fails to account for loss of airflow from filters, and forgets about the PSU fan.
At the pressure level of a computer case, there is no purpose in attempting to finely balance air pressure to be just on the positive side.
Here is how I set up my case:
Two Filtered Panaflo L1A intakes in the front, one in the top. Two Panaflo L1A's as exausts - one in the back and one in the PSU.
Why:
Intake 1 - Front Intake blows directly on my hard drive.
Exaust 1 - The PSU needs a fan to adequately cool it
Exaust 2 - Draws air across the CPU
At this point my components are adequately cooled, but I have a dust problem.
Solution - positive air pressure.
I look around and see that I still have two mountings available - in the Front and top, so I put intake fans there.
Result - no dust, and the fringe benefit of overall cooler temperatures.
Downside - a little too loud for my taste, but that's another discussion.
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dukla2000
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My 6p.
Fan locations are more about where your air goes in or out. We are all here cause of noise, and each extra fan increases noise. So either have all your fans as intakes, or all as exhausts, is my view. Anything else is too many fans.
My case has a single 120mm (@ 7V) intake at the bottom front - as per post in PSU forum I have even removed the fan from my psu. This setup works for me (and when I get bored I have 6 thermometers measuring various temps on my setup) - even at full load nothing is going above 50C (ambient circa 20C).
Fan locations are more about where your air goes in or out. We are all here cause of noise, and each extra fan increases noise. So either have all your fans as intakes, or all as exhausts, is my view. Anything else is too many fans.
My case has a single 120mm (@ 7V) intake at the bottom front - as per post in PSU forum I have even removed the fan from my psu. This setup works for me (and when I get bored I have 6 thermometers measuring various temps on my setup) - even at full load nothing is going above 50C (ambient circa 20C).