Rig Refurbishment: Airflow Direction in Corsair 540, fans and loop questions

[littleben]

Hi, bin a few years since I built my PC, A huge accumulation of dust, very poor temps for a while now, and suddenly a few days ago a large bubble appearing in my loop have lead me prepare for a long overdue refurbishment this weekend.

Here is how my fans are laid out: https://ibb.co/iGLcr7

And the current direction of airflow: https://ibb.co/hfQz4S

I think I may have misunderstood the direction of the air flowing through my fans when I did my build. At the moment warmer air from inside the case (presumably warmer?) over the radiators, it makes more sense to me to have cooler air flowing from outside the case over the radiators??
I took the side of my case recently and the average temps seemed to go down a few degrees which seems to back this idea up.

Or perhaps I should have one radiator going in and the other out, or any other configuration?

I have just bought some new fans (upgraded from Corsair SP120's Quiet edition to performance edition) - I wanted to check something about the fan type - I understand the SP fans are better against the resistance caused by the radiators. With my larger radiator having fans on both sides would it be better to have one side with SP fans pushing against it and AF fans drawing away from it on the other side?? Perhaps a stupid idea.

A final question - I bought my rampage iv extreme motherboard from a friend with water blocks installed on everything. I now understand that cooling ram (Corsair Dominator GT 4x4gb)) is pretty pointless - Does anyone know if I will get a decent temperature drop if I omit them from the loop? Worth bearing in mind that a) I don't have the passive cooling strips that sit on top of the ram to put back on and b) all my pipes are hand-bent acrylic and the thought of having to bend some new pipes to miss out the ram out gives me a headache.

Any help much appreciated and thanks

 

[Armageus]

Airflow generally should be intake at the front/bottom and exhaust from the top/rear.

Based on that, then yes you need to change your front radiator fans all to intake, and change the rear fan to exhaust.

With there being 6 fans at the front, this should also provide positive air pressure which will help to reduce dust build up (although I'm not sure if the 540 has front fan filters?)

 

[LuckyBenski]

Airflow generally should be intake at the front/bottom and exhaust from the top/rear.

Based on that, then yes you need to change your front radiator fans all to intake, and change the rear fan to exhaust.

With there being 6 fans at the front, this should also provide positive air pressure which will help to reduce dust build up (although I'm not sure if the 540 has front fan filters?)

One good arrangement is front intake, rest exhaust. But that is from way back before liquid cooling and when components were smaller. The 'heat rises' concept doesn't apply much outside of still air. The airflow in a PC case negates it mostly, though warm air can gather in especially still areas the the top of a case.

That said, tuning the case and fans as an entire system is most definitely important - you currently have far more exhaust than intake. Plus side - air in the case won't have heat added from radiators. Negative side - radiators will receive small amounts of warmish air. A good balance might be to have one radiator as intake and the other as exhaust. This way, the internal components will see more airflow, and pressure in should be more equal to pressure out.

Your call which ones should be in and which out, but it might make sense to keep whatever the rear fan is doing, matching the radiator next to it. I also think one exhaust fan in free air is healthy to prevent pockets of warm air.

Consider also, the arrangement of fans on rads. A fan pushing air onto a radiator traps any dust against the radiator. But a fan pulling air through a rad, leaves dust in the opposite side of the radiator. This can be easier to clean without disassembly. Obviously not that relevant with push/pull arrangements.

Also, two fans in-line like in your push-pull front rad, don't equal double the air flow. They work less hard, and can apply more static pressure, but only maybe 10-20% more air passes. More efficient, rather than double the numbers.

So my suggestion, one possible solution: push/pull intake on your front triple. Top radiator as exhaust, with fans on top and radiator underneath so air is being pulled not pushed through them. Then rear fan as exhaust. This equates to roughly three fans in and three out, creates good crossflow of motherboard, and ejects any hot air that does rise out of the case. Plus, I I love the look of radiator fins more than fans

 

[Habakkuk]

The usual 'in at front, out at rear top' also helps cool the passively-cooled southbridge - the northbridge should be cooled from the cpu fan.

 

[doyll]

Make sure you have at least as much exhaust vent area as you have intake vent area. If intake vents all have fans than exhaust vent area needs to be about 1.5 times as much without fans. Here is a link to case airflow tutorial. I wrote it mostly for air cooling but the airflow principle is the same water cooling.
https://forums.overclockers.co.uk/t...-i-put-my-temp-sensor.18564223/#post-26159770

 

[littleben]

Thanks for all the info guys. Gonna do Front intake (this will also help with cleaning in future, at the moment cant get behind fans inside case, now will simply be able to take front fans off and dust). The top radiator fans and back AF fan as exhaust.

I should also be able to flip the top radiator fans if I want to experiment with the airflow and see if there is better temps/less dust accumulation.

 

[doyll]

Maybe put filters on all vents with only intake fans. With decent fans all you need is intake fans. Bottom line here is whatever air enters case has to leave it too / any air leaving case has to first enter it. I build a couple systems a month and in last 2+ years I can't remember any with exhaust fans. OcUK sell D
DEMCIflex and Silverstone vent filters. Full set of DEMCIflex for A540 are £70, but if you shop around you can probably find some for just intake vents for much less money .. or you could even make your own out of GF's pantyhose.

 

[Rroff]

The 540 has fan filters on the front - if you are drawing air in the back and out the front with the stock filters in place you will actually cause a build up of dust inside the case.