Need some help with fan config in my Enthoo lux

enigma27 · 1 Jul 2016 at 10:16

Morning All.

So built my new system yesterday but wanted some advise on my fan set-up and whats the best way to handle it.

So currently i have the following custom loop.

360 Rad, GPU, CPU, Pump/res all in the loop. Attached to the Radiator I have 3 Vadar fans pulling air up through the rad. I also have one 3 pin AF120 on the back pulling out and 2 AF 120 on the front pulling in.

So my question is around how to control these fans... So i have a Luxe case with a PWM hub and have the fans set-up as follows.

PWM hub --> CPU fan header
AF 120 in socket 1 of the hub (this is the fan the hub uses to sync voltages withe the other fans)
Socket 2 & 3 AF 120 at the front
The 3 vadar fans are connected to a PWM 3 way splitter that then plugs into the PWM hub. This is all controlled via the motherboard software.

The fan hub is powered by a Sata connection

Now here is where the problem lies.. Last night i popped the top filter off and realized that only two of the three rad fans were spinning at idle... the AF 120 are all spinning... this got me thinking may the PWM fans don't like being controlled by voltage..

So trying to work out whats best..

The mobo has 5 sys fan headers but according to the manual only the CPU header is PWM the rest are voltage controlled.

Would the cpu header be enough to run three pwm fans?

I am thinking ditch the PWM hub altogether and simply plug the 3 way pwm splitter into the CPU header and run the PWM fans from that and then use the system fan headers to run the 3 AF 120 non pwm fans (each on its own header)

Anyone got any advise would be helpful.

enigma27 · 1 Jul 2016 at 10:18

just to add the reason I am trying to sort this is that my GPU with full cover block idles at 37 which i thought was quite high for a water cooled GPU but then when i released that only one rad fan was spinning it made me thing that maybe heat was not being ejected out quick enough to cool the GPU right down..

A quick test of heaven and GPU never exceeds 60 degrees.

enigma27 · 1 Jul 2016 at 12:40

Ok had a long hard think and I may have solved it..

So i am going to bypass the PWM controller on the case completely..

I have picked up a PWM controller that has 5 connections plus Sata power which i will run from the CPU header and then plug the three AF fans into the Sys fan connections... i should then be able to control the Rad fans and case fans seperate

doyll · 1 Jul 2016 at 18:54

so you plan to run 4x 120mm exhaust fans and only 2x 120 intakes? This means a half of the air leaving the case is all the front intakes can supply, so any other air the exaust fans flow has to flow into case through vents wiht no fans or filters.

This problem is compounded by the fact the Vardar fans are much better at moving air than SP120 corsail fans by a facter of 2x SPs to 1x Vardar.

What is the purpose of the rear exhaust fan?
Why are you using 2x 120mm front fans in a case that can use 2x 140mm fans?
I would use the 2x PH-F140SP fans that came with the case as front intakes and pick up one more to use as a bottom intake .. no exhaust fans except the radiator up top.

If you look at the bottom case filters you will see the fit in almost touching each other. Tape them together and you should be able to pull the PSU filter out the front with the bottom front filter. This way you can clear the PSU filter without having to move the case.

I've done this on a couple Enthoo Luxe and Pro cases, but can't remember for sure if there was any stop on PSU filter, but I don't think there is. I only remember that taping the two bottom filters together with about a 5mm gap between them because if they were tight together there the very back of PSU filter was in a little too far and unfiltered air leaking through a small gap at the back.

BluD · 1 Jul 2016 at 21:22

If theyre all connected to the same hub and some are running but not others then its probably just because the fan your using for the hub control has a much lower startup speed, so your fans that require the same voltage to start up will spin but your fans that require more, in this case im guessing the vardars wont spin. Just stick a vardar as your control fan.

Also like doyl says positive pressure helps keep dust out as it always hits a filter on its way in, negative pressure pulls air into all the non filtered gaps and youll need to clear out the dust from your rads/sinks a lot more often.

enigma27 · 1 Jul 2016 at 21:23

All sorted.

Changed the rad fans to push and put them on their own pwm and the other three fans on the mobo sys connectors.. GPU is idling at 31 and cpu at 29

Heaven benchmark showing GPU now not going over 50

I can change the rear from an out to an intake but temps are fine now so not sure if it will help anymore

doyll · 2 Jul 2016 at 08:30

BluD said:
If theyre all connected to the same hub and some are running but not others then its probably just because the fan your using for the hub control has a much lower startup speed, so your fans that require the same voltage to start up will spin but your fans that require more, in this case im guessing the vardars wont spin. Just stick a vardar as your control fan.

Also like doyl says positive pressure helps keep dust out as it always hits a filter on its way in, negative pressure pulls air into all the non filtered gaps and youll need to clear out the dust from your rads/sinks a lot more often.

As a general rule the RPM signal from fan to motherboard is not 'monitored' or used by the motherboard for anything but fan warning if fan is not running. . It is only so we can see what the rpm of the fan is. The motherboard uses heat to determine voltage or PWM signal speed to fans, not RPM. As heat rises, the motherboard increases voltage / PWM signal. The end result is fan speed increases and temps are controlled.

The neg / pos pressure thing is kinda misleading. It's is really "Pressure Differential" between outside and inside of case, of between intake and exhaust side of fan. This pressure difference is very very little.

For example, we all know that the air pressure is less the higher above sea level we climb. At sea level the pressure is 14.7 pound per square inch while at 5.84 meters above sea level it is 14.69 psi. 0.01 psi difference from toes in the ocean and standing 6 meters above the ocean. That is is a difference of 70.3 mm H2O

The pressure difference our fans are capable of is from something like 1.0-3.0mm H2O.

The total pressure a fan makes is less than walking away from the ocean a few meters. Not even enough to make our ears pop like when driving over a mountain pass or flying in an plane.

enigma27 said:
All sorted.

Changed the rad fans to push and put them on their own pwm and the other three fans on the mobo sys connectors.. GPU is idling at 31 and cpu at 23-70 times more than

Heaven benchmark showing GPU now not going over 50

I can change the rear from an out to an intake but temps are fine now so not sure if it will help anymore

While your temperatures are fine, you will get a lot more dust and lint in your case if you do not increase the filtered intake airflow so air is leaking out unused vents rather than in.

But it's your choice.