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Reverse airflow?

post #1 of 10
Thread Starter 
Hey everyone,
When I built my PC I wanted my CPU to get the coolest air possible so I have my top radiator pushing air into the case. The thing is I have lightnings dumping heat in my case, so I got rising hot air being pushed down by the radiator airflow. I'd like to know if reversing the airflow of my side panel (currently pushing air in) to suck the hot air out as it's dumped into the case. I'd like to avoid reversing all my rad fans because it's going to be very tough taking the screws out with everything in place
Thanks!
    
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post #2 of 10
Fans easily overpower any convection forces caused by rising hot air. Yes the hot air still wants to rise, but it's really only a few degrees hotter than ambient so it's not that powerful of a force to fight against.

My case, the FT02, is built around the idea of vertical airflow. However, there was a test not that long ago where somebody compared the performance of that case between vertical and the case laying on its side. It performed virtually the same. The high performance cooling of the case doesn't come from the vertical airflow, but simply the amount of airflow provided by all of its fans.

So to answer your question. I think I would leave the side panel blowing air in. I'm a fan (pun intended) of positive airflow. The air will still find its way out of your case as long as you have an exhaust fan.
Edited by Epitope - 10/19/11 at 8:02am
    
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post #3 of 10
Thread Starter 
Thanks for your input. The thing though is that I want the GPU heat to go away, I believe it builds up at the bottom of my case because air pressure is keeping it down. Therefore I have hot air leaking out through the front of the case even though there is no fan there!
    
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post #4 of 10
The air coming out of the front would be caused by the positive pressure nature of your current setup. You have more air in then air out, so the enter that is in and entering your case is forced out by the air entering behind it. Thats a good thing.
post #5 of 10
As said above, you want to try and keep the same amount of inflow then outflow - i had this problem in one of my cases... Now i have overkill on fans, i feel you can never have to much airflow

Personally i try and keep the same amount (MM) of air flow in, as out.

Plus good cable management is a added plus to your heat issue.

If i have 1, 120mm fan in, i try and get a 120mm fan out... I also direct my airflow, so my front panel, and top panel and my side panel are all blowing in, and my top and side are blowing out. With good management on cables etc, this should increase the amount of airflow - in turn increasing heat transfer


What you could do is post some pics, or some diagram of just a simple

1, 120 mm fan \\ front panel \\ intake
2, 120 mm fan \op \\ intake
1, 120 mm fan back out.




Id be glad to help, i am an avid air cooled person i have some OCD on optimizing my airflow.
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post #6 of 10
Quote:
Originally Posted by apgfeb14 View Post
As said above, you want to try and keep the same amount of inflow then outflow - i had this problem in one of my cases... Now i have overkill on fans, i feel you can never have to much airflow

Personally i try and keep the same amount (MM) of air flow in, as out.

Plus good cable management is a added plus to your heat issue.

If i have 1, 120mm fan in, i try and get a 120mm fan out... I also direct my airflow, so my front panel, and top panel and my side panel are all blowing in, and my top and side are blowing out. With good management on cables etc, this should increase the amount of airflow - in turn increasing heat transfer


What you could do is post some pics, or some diagram of just a simple

1, 120 mm fan \\ front panel \\ intake
2, 120 mm fan \op \\ intake
1, 120 mm fan back out.




Id be glad to help, i am an avid air cooled person i have some OCD on optimizing my airflow.
It's impossible to have more intake than exhaust or more exhaust than intake. Otherwise the case would either fill up with air and explode or suck empty until it became a vacuum and crush like soda can that has been stepped on. If you have more intake fans than exhaust fans there will be a slight positive pressure inside your case, this will cause the air to accelerate out of any holes in your case. If you have more exhaust fans than intake fans then air will suck in through any opening in your case.

My FT02 has 3X 180mm fans and only 1 low speed 120mm exhaust. It is generally accepted as the best air cooling case. It has extremely more intake than exhaust. You can feel the positive pressure. I can feel air blowing out between the gaps in my 5.25 bay covers. That's how much positive pressure it has.

It is my opinion that intake is almost always better. Force more cold air inside your case and it will fine a way to exhaust as long as you have at least 1 exhaust fan. however each case is different and it isn't really a rule.
    
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post #7 of 10
Thread Starter 
Very nice read! I'll post some reps and a diagram after work. I don't have any heat issues, I just thought it was not optimal but it does sound like I'm pushing the positive pressure lol! I have one rear exhaust, the rest is intake, some serious intake lol. Gonna keep my case as it is me thinks!
    
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post #8 of 10
Quote:
Originally Posted by Emmanuel View Post
Very nice read! I'll post some reps and a diagram after work. I don't have any heat issues, I just thought it was not optimal but it does sound like I'm pushing the positive pressure lol! I have one rear exhaust, the rest is intake, some serious intake lol. Gonna keep my case as it is me thinks!
Think you made the right choice.
post #9 of 10
I agree and i dont deny that you cant have more or less air, its obvious since computer cases are not air tight. But if you can move the air quicker, im sorry that what i was getting at, if you can move the air quicker, then he should, that would "optimize" your airflow.

Lets see some picks or something!
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post #10 of 10
the idea of a positive air pressure case is NOT to actually pressurize your case to any significant amount. the idea is to provide KNOWN intake source so the air can be filtered and dust will not be able to come into the case through any other openings in the case.

the IDEAL positive pressure case is one that is has SLIGHTLY higher pressure then ambient so that the positive pressure will enhance the efficiency of the exhaust fans by eliminating back pressure created by the exhaust fan sucking air out of the case.

another benefit of a positive pressure case is your ability to control exactly where the cooling air goes without using additional fans. by eliminating possible exhaust sources, you can channel the cool air to go exactly where you want it to go because you have total control over the location of the exhaust.

positive pressure case is designed around the idea of efficiency. using the least amount of air to accomplish exactly what you need to accomplish. generally speaking, a "well designed" positive pressure case is very quiet because of that.
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