Airflow / Fan Orientation

Puppetmaster · 24 Apr 2013 at 16:03

Hello

Currently I have an 800d with a 360mm SR-1 in the roof with 3x SP120 as exhaust fans operating in pull. I have 2 AF140's as intake, 1 at the rear one at the midsection. See the awesome picture below. (left arrow got messed up due to the eraser tool in paint.net :s)

The intake fans dont seem to be bringing in much air at all. They are run on a fan controller but even when turned up full, there isnt much going in.

Would it be a better idea to turn the 3 radiator fans into intakes and set the rear AF120 as an exhaust? I was also thinking of adding 3 more fans and running push pull on the rad.

Thoughts?

DaleTheWhale · 24 Apr 2013 at 16:08

Do you not have any front intakes?

I'd keep the rad as an exhausts, as heat will rise naturally anyway.

Puppetmaster · 24 Apr 2013 at 16:13

ThaReaperGuy said:
Do you not have any front intakes?

I'd keep the rad as an exhausts, as heat will rise naturally anyway.

The 800d doesnt have any front intakes. It has 1 fan blowing over the hotswap hdd cage and another i believe can be mounted at the bottom to cool other hdd's. I cannot mount anything in the 5 1/4 bays as I have a fan controller and 2x bay res.

My temps are pretty good but was wanting to drop them even more for when running high load on both gpu's and cpu without needing to put fanspeed up.

DaleTheWhale · 24 Apr 2013 at 16:27

Ah, I think how you have it is pretty much the best you can get, having the rear as an intake and the top as exhausts would be the better option. Adding the 3 fans might have a noticeable difference to get some warm air out the case really. Would be handy to have a single front intake just to get some fresh cool air into the system.

What are your temps?

SirConfused · 24 Apr 2013 at 20:02

I have just done a build in the 800d and i've gone the opposite direction.

Triple rad up top as intake and the back as the only exhaust. Positive pressure is the way to go as it will keep more air circulating through the case, despite some of it being warmer from the rad intake.

I'm absolutely cooking an old bloomfield i7 and my temps are still not budging

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Puppetmaster · 24 Apr 2013 at 20:16

SirConfused said:
I have just done a build in the 800d and i've gone the opposite direction.

Triple rad up top as intake and the back as the only exhaust. Positive pressure is the way to go as it will keep more air circulating through the case, despite some of it being warmer from the rad intake.

I'm absolutely cooking an old bloomfield i7 and my temps are still not budging .

Thats very good to hear. I did some research earlier and found various people switching the top 3 fans to intake and having a good effect. Planning on doing a rebuild over the weekend, will switch rad to intake and add a second set for push pull. Going to give the case a good clear out and fit an extra 1 or 2 fans down the bottom. Should help things a fair amount.

ubersonic · 24 Apr 2013 at 21:43

SirConfused said:
Positive pressure is the way to go as it will keep more air circulating through the case, despite some of it being warmer from the rad intake.

Positive/negative pressure have no effect on air circulation, lack of circulation happens in both positive and negative pressure environments, the way to avoid it is to have as clear a path for air to flow throughout the case. The reason people advocate positive over negative for computer cooling is because negative is a vacuum and as air will take the path of least resistance it will rather come into a vacuum via a gap in the case panels than through a dust filter, and so cases under negative pressure (I.E old style ones with just a rear fan) are dust magnets.

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@OP The best method with roof/rear fans and water cooling is to have the roof as extract and the rear as intake, tried and tested. In your case the two AF140's will be pumping in more air than the three SP120's can extract which is how you want it.