Large Radiator on top of case

[quicksilverXP]

I Plan to put a double heater core on top of the case and was wondering if the directions of the fans should bring air from outside the case through the radiator and into the case or should the fans brings air from inside the case, through the radiator, and outside the case.

[SemiCycle]

So you don't disrupt the normally flow of air in the case, you should have the fans at the top of the case blow the air out.

[jkb2198]

You could also try one fan push the other one pull and see what kind of case temps you get opposed to both pulling.

Keep clocking

[murdok5]

here is waht i was thinking.....

im looking to install 2 loops on a lian-li pc70 case.
i was goin to put radiators above teh PSU both venting out of the top of the case, with 120mm fans on each....

now should i put a fan on the back of the case blowing air in for these ?? would that even help out?


mike

[felinusz]

now should i put a fan on the back of the case blowing air in for these ?? would that even help out?

I wouldn't bother with another fan blowing air in the back of the case for the radiator.

Look at it this way, with the average case setup, you have air entering the front and bottom side, and exiting the top, and case upper rear. Don't worry about 'hot air' blowing through your ceiling mounted radiators and decreasing performance of your top mounted radiators - Turbulence and airflow should be signifigant enough that 'overflow' fresh air from outside the case is still being drawn up and through your top radiator, without stagnating and gaining heat for very long.

In my case I have four 120mm fans (2 push pull sets, on two radiators) in the front of the case, and one 120mm fan installed in the side door of the case. These are my intake fans.

I have a ceiling mount radiator, with two 120mm fans also blowing push pull, my two PSU fans, and two 80mm fans at the back of the case blowing exhaust. These are my exhaust fans.

I have set up incense smoke to blow through the fans without radiators attached, and I found that the top 120mm fan actually pulled air out of the case almost as fast as it entered from the front two 120mm fans. The PSU and 80mm fans also kept the air moving through my case very quickly, the side mounted 120mm fan creating a lot of airflow and 'overflow' over where the motherboard and video card would be. All my fans are Evercool Aluminum 25mm thick fans - they aren't even beastly powerful. I also have a large full-tower case with a lot of air space in it.

What I'm trying to sum up is that ceiling mounted radiators should not experience drastic performance loss, as the air hasn't really been stagnating and heating up very long. I feel that the performance gained through a regular in/out airflow pattern in your case will outweigh the slight performance gained by having your ceiling radiator fans blowing intake instead of exhaust.