The elusive neutral case pressure

[cptjackawesome]

Hello everybody, 

 

First post on here, but it's a doozy. 

 

So I am on V2 of my build, with a i7-7700k (soon to be delided) and GTX 1070, both overclocked and connected to a custom water loop which has a 280mm and 120mm radiators hooked to it inside a Fractal Design Define R5.

 

I know the rad in the photo is a 240, but I bought the EX280 and will be taking the push fans out too, relying on the GP14 fans that came with the case for pull.

 

Problem is, my case pressure is really negative and a month in I'm already getting dust accumulation..

 

Now, as you can see in the attached photo, I have a POS intake fan on the bottom I want to swap out, but I am having trouble finding the right one to get.

 

When all is said and done, i will have 2 Fractal GP14 fans running at full speed in the front, and a 120 fan for the 120mm (looking at a SP120 for that one).

 

At this point, is there a fan that can sit on the bottom by the PSU that can bring me to neutral pressure, if not positive, without sounding like a jet engine?

 

Or is there a different configuration someone can think of that would improve pressure without sacrificing heat expulsion?

 

I was looking at the Noctua industrial 3000rpm, but that thing is loud, 

 

Any thoughts anyone has would be greatly appreciated.

 

Thank you all!

[GDRRiley]

just don't run a fan on the bottom.

[cptjackawesome]

1 hour ago, GDRRiley said:

just don't run a fan on the bottom.

Wouldn't that just increase my negative pressure? 

 

Or are you saying I should put the fan somewhere else? 

 

If so, the top is out, as I keep my router, modem, Nas, etc. on a shelf that sits above the rig. 

 

I was thinking the bottom, since I have space there, and the screen on the bottom is great for intake. 

 

What would you do given this scenario? 

[PrimeSonic]

I'd suggest running the radiator in the back in push/pull and getting rid of the fan in the bottom of the case.

 

And also see if you can get the fans on the intake running just a bit faster than the fans doing exhaust.

 

If your problem is dust accumulation, then you really want to aim for positive air pressure over neutral.

Just try to get more air coming into the case so that it forces dust out through all the gaps rather than it sucking dust in through the gaps.

[cptjackawesome]

Thanks sonic, 

 

I'm fully aware of the concepts of positive case pressure. The quandary I was having was on how to design it so that I could achieve enough intake with my current limitations. 

 

I just bought 2 140 noctua industrial ppc 2000 rpm fans and I am going to do one of the following:

 

If my 280 rad fits on the bottom, I'm going to put my gp14 fans on the rad pushing hot air out the bottom, and put the noctuas in the front as intake. The case has voltage control for the front fans, so I can adjust the speed to get neutral/positive pressure.

 

If the rad doesn't fit on the bottom, I am going to put one noctua on the bottom as an intake and attach it to my mobo, then put the other on the side panel as an intake with a filter I got on ebay and use my uefi to get the speeds just right. 

 

Either way, I'll have 2 heavy duty blowing in and that should hopefully get me to where I want to go. 

 

Thanks for your help everyone.