Got a Corsair 550D! Here's my fan setup:

[PCJake]

(I posted this as a response in my General Hardware thread, but I wanted to make sure everyone here in Cooling could chime in as well)

I got my 550D today, and the engineering on it is fantastic. I can see the logic behind everything they did.

Here's a diagram of the fan setup I'm planning, and some thoughts below it:

• The 120mm front intakes would both be Noctua NF-S12A fans - these are low impedance fans that should simply bring air into the case.
• The 140mm bottom intake would be an NF-A14. The blade design on this should create a more focused, straight-line type of flow. So, not only would it draw cool air in from the bottom, it should also direct the cool air from the 120mm front fans to the top of the case.
• The rear 140mm exhaust would also be an NF-A14. Not much to say here. My NH-D14 CPU cooler should pull in the cool air from the front, exhaust it towards the back, and then the NF-A14 rear exhaust should pull it out of the case.

There we go. Is this logical?

 

[taq8ojh]

I wouldn't bother with bottom fan. There's SO little space between floor and the case it makes it borderline useless. Just like the front fans, by the way (only not AS bad): unless you have the "doors" permanently open, there's hardly any airflow because of so tight space. You would have to run fans at extreme speeds to be able to suck any reasonable amount of air in. I tried hard, trust me. Didn't work at all.

 

[lehtv]

I wouldn't bother with bottom fan. There's SO little space between floor and the case it makes it borderline useless. Just like the front fans, by the way (only not AS bad): unless you have the "doors" permanently open, there's hardly any airflow because of so tight space. You would have to run fans at extreme speeds to be able to suck any reasonable amount of air in. I tried hard, trust me. Didn't work at all.

One could reason that given how the door obstructs intake airflow to the front fans, it is therefore important to use the bottom fan to compensate for that. I.e. if the front door was always open, there would be no need for a bottom fan.

I'd also add that some airflow is better than no airflow. I'm using a Define R3 myself, and the front fans are definitely useful even with the door closed. In fact, the improvement in temperatures with the door open and fans at full blast isn't that great, whereas disabling the front fans altogether means I get negative air pressure and dust buildup.

 

[Charlie98]

I think the bottom fan would be necessary to maintain positive case pressure, given the restrictions with the enclosed front fans. I think the bottom fan port on the 550D has a dust screen... if it doesn't I would get one.

I only have the single front fan on my Define Mini running at about 60% but judging by the amount of dust plastered to the front filter it moves plenty of air. (YMMV with the 550D ) In fact, I have another Fractal fan setting on the desk to install in the 2nd port in an attempt to pump up the case pressure.

...I think you are on the right track, OP.

 

[PCJake]

I wouldn't bother with bottom fan. There's SO little space between floor and the case it makes it borderline useless. Just like the front fans, by the way (only not AS bad): unless you have the "doors" permanently open, there's hardly any airflow because of so tight space. You would have to run fans at extreme speeds to be able to suck any reasonable amount of air in. I tried hard, trust me. Didn't work at all.

Yeah, I see your point. But I suspect the front and bottom fans will move more air than you think they will. I will do Prime95 and Unigine tests for three different fan setups:

• 3 stock fans in default configuration
• 3 Noctua fans in default configuration
• 4 Noctua fans (3 in default configuration + 1 bottom intake)

I'll post back once I know how much difference the bottom one makes.

I think the bottom fan would be necessary to maintain positive case pressure, given the restrictions with the enclosed front fans. I think the bottom fan port on the 550D has a dust screen... if it doesn't I would get one.

I only have the single front fan on my Define Mini running at about 60% but judging by the amount of dust plastered to the front filter it moves plenty of air. (YMMV with the 550D ) In fact, I have another Fractal fan setting on the desk to install in the 2nd port in an attempt to pump up the case pressure.

...I think you are on the right track, OP.

It does indeed have a dust screen. Thanks for the feedback.

 

[taq8ojh]

While I didn't try the bottom fan approach myself, I did try one and two front fans at various speeds. Of course every setup is different, but in my case I observed almost exactly zero difference in temperatures. This was after a period of time under full load.
What made the biggest difference in my case was higher speed of rear fan. Interestingly, top fan made very little (yet observable) difference.

 

[PCJake]

While I didn't try the bottom fan approach myself, I did try one and two front fans at various speeds. Of course every setup is different, but in my case I observed almost exactly zero difference in temperatures. This was after a period of time under full load.
What made the biggest difference in my case was higher speed of rear fan. Interestingly, top fan made very little (yet observable) difference.

Did you have a rear-exhaust style CPU heatsink/fan? Stronger rear fan airflow seems to help a lot with that style of heat sink.

 

[taq8ojh]

Yes I do. I originally thought top fan would help a lot since hot air raises, but apparently logic doesn't always apply

 

[lehtv]

Yes I do. I originally thought top fan would help a lot since hot air raises, but apparently logic doesn't always apply

In my case it does actually help by a couple of degrees, my heatsink is so bulky that the top rear fan is actually quite close to it

 

[taq8ojh]

If I actually get to replace my memory with low-enough profile, I might be able to turn the bloody cooler by 90 degrees, and then the top fan might be of some use. But couple degrees (like, 5 or so) is my experience as well.

 

[ElFenix]

One could reason that given how the door obstructs intake airflow to the front fans, it is therefore important to use the bottom fan to compensate for that. I.e. if the front door was always open, there would be no need for a bottom fan.

I'd also add that some airflow is better than no airflow. I'm using a Define R3 myself, and the front fans are definitely useful even with the door closed. In fact, the improvement in temperatures with the door open and fans at full blast isn't that great, whereas disabling the front fans altogether means I get negative air pressure and dust buildup.

air isn't near as obstructable as people on the intertrons seem to think. i wouldn't use a bottom fan just cuz my case is on carpet, but front fans definitely help.

 

[lehtv]

Fully agreed

 

[PCJake]

air isn't near as obstructable as people on the intertrons seem to think. i wouldn't use a bottom fan just cuz my case is on carpet, but front fans definitely help.

I've always thought that too.

 

[Charlie98]

Interestingly, top fan made very little (yet observable) difference.

Same with the big 200mm top fan on my HAF922 case... no difference. I considered flipping it... turning it into an intake fan but I'm just going to dump the swiss-cheese HAF case and get another Define Mini.

 

[taq8ojh]

Get HAF XB then, it's sexy as hell

 

[Remobz]

Does that case need a micro mobo or can it handle a full size mobo?

 

[taq8ojh]

Full works.

 

[MadScientist]

Since everyone's system is different and there's too many variables there's no right or wrong answer to the OP's question.

Here's a few articles that may help.
http://www.bit-tech.net/hardware/2012/02/10/the-big-cooling-investigation/1

http://www.hardwaresecrets.com/article/Which-is-the-Best-Place-to-Install-a-Case-Fan-Part-2/1483/1

 

[tengen]

I wouldn't bother with bottom fan. There's SO little space between floor and the case it makes it borderline useless. Just like the front fans, by the way (only not AS bad): unless you have the "doors" permanently open, there's hardly any airflow because of so tight space. You would have to run fans at extreme speeds to be able to suck any reasonable amount of air in. I tried hard, trust me. Didn't work at all.

I disagree. I have owned the 500R, which shares the exact same metal chassis and layout as the 550D. I've gone through a fair amount of fans experimenting with the layout to reduce temperatures. I've found having a single fan on the bottom greatly reduced my GPU's VRM and core temps, as much as 15C under load. To top it off, it wasn't even a fancy fan - I just threw the stock 500R LED fan on the bottom as intake just for kicks. It did more than swapping the front (both HDD cage and front intake) fans with AP15s, SP120s, Cougars, or P12s, or the side panel ones (although they did help too).