fans set up on new build

[danlightbulb]

Hi all,

I am going to be building my own pc and not sure how to set up the fans.

I will be buying this case:
Fractal Design Core 1000 Case & Super Flower 450W FX 80 Plus Bronze Power Supply Bundle= £48.95

Which has room for 1 front 120mm fan, 1 side 120mm fan and 1 rear 92mm fan, all not supplied.

So I was going to buy these fans:
2 x Arctic F12 PWM Case Fan - 120mm= £4.39

1 x Arctic F9 Pro PWM Case Fan - 92mm= £3.98


The motherboard I am getting only has one case fan header.

So my question is how to set up these fans? The description on the larger 120mm fan seems to imply that they can be daisy chained, is this correct?

"The ARCTIC F PWM forward the PWM signal from the CPU to the whole case ventilation system."

and the 92mm fan picture appears to have more connectors coming off it.

So can I join these fans together off the one fan header, or do I need to buy additional equipment? And what configuration of fans do I use for intake and exhaust?

Thanks

 

[Danny75]

Hi Dan,


My basket at Overclockers UK:

• 2 x Cougar Black HB CFD12 Fan, 120mm= £5.99
• 1 x Aerocool Dark Force Fan - Black - 90mm= £4.99

Total: £21.63
(includes shipping: £4.66)
​

​

The difference is that both also include molex adapters to connect straight to PSU (as well as the normal 3-pin connector). I've used the Aerocool Dark Force 90mm and was surprised it wasn't noisier at 1800 RPM, and at how much air it pushed. Ideal rear fan on 90/92mm mounts, imo. Also, your motherboard will have room to connect one chassis fan, so if not entirely happy with noise you can connect that one to motherboard and control it.

The Cougar Blacks include molex adapter too for PSU and seem to have decent CFM/noise ratio, on paper. Hopefully in reality it won't be too far off. Cougar fans do have a decent reputation.

Try front intake, side intake, rear exhaust (and your PSU fan should also exhaust).

 

[danlightbulb]

Try front intake, side intake, rear exhaust (and your PSU fan should also exhaust).

Ah thanks for the alternative option. I'll take a look.

Do PSU fans exhaust then, generally? I had assumed it was sucking through that grille. I'm looking at two case/PSU combinations at the moment. The first one I posted above has a PSU with it but its not modular, so I'm looking at a second case/PSU which is a bit more expensive but already comes with one fan, and a semi-modular PSU.

My basket at Overclockers UK:

• 1 x Aerocool VS-1 Midi Tower Gaming Case - Black Window= £20.99
• 1 x Xigmatek Maverick 500W '80 Plus Bronze' Semi Modular Power Supply= £39.95

​

I'd just need a front intake fan I guess to go with this one then if the PSU fan is exhausting too.

So sorry another noob question. Which way up does the PSU get mounted? Fan on top or bottom:

Thanks

 

[Danny75]

Do PSU fans exhaust then, generally? I had assumed it was sucking through that grille.

They intake through their fan and exhaust through their grille.

In the Fractal Core 1000 the PSU goes above the motherboard at the rear instead of the now more common/modern PSU-at-bottom location.

I'm looking at two case/PSU combinations at the moment. The first one I posted above has a PSU with it but its not modular, so I'm looking at a second case/PSU which is a bit more expensive but already comes with one fan, and a semi-modular PSU.

Try to avoid sacrificing PSU quality for the modular/semi-modular feature. The quality should come first. For Xigmatek to provide semi-modularity at that price they'll likely have skimped a lot on quality.

I'd just need a front intake fan I guess to go with this one then if the PSU fan is exhausting too.

Incorrect. On this other case, the PSU is located at the bottom, intakes through the bottom and exhausts through the rear. So a rear exhaust fan at the top is advisable to exhaust air from inside the case.

So sorry another noob question. Which way up does the PSU get mounted? Fan on top or bottom:

For bottom-mounting, as in this case, preferably with its fan facing downwards. If it doesn't have a dust filter on the bottom you could have the fan facing up instead. But you will still want a rear exhaust fan higher up because the PSU will just deal with a little of the hot air from GPU and not the hot air above the GPU. And it won't be very efficient at extracting hot GPU air anyway.

Thanks

Very welcome.

 

[danlightbulb]

Try to avoid sacrificing PSU quality for the modular/semi-modular feature. The quality should come first. For Xigmatek to provide semi-modularity at that price they'll likely have skimped a lot on quality.

Ah I see. This is the one that comes with the Fractal case:

https://www.overclockers.co.uk/super-flower-fx-450w-80-plus-bronze-power-supply-black-ca-035-sf.html

But this kind of put me off it compared to modular PSUs:

Especially if the PSU is top mounted - where would all those cables go? Also not really sure how many of these I'll use?

But if you think the Xigmatec one will be skimping then I'm not sure what to do for the best. They are both relatively cheap ones I guess.

Sorry I'm venturing into the wrong topic for this section of the forum now.

Incorrect. On this other case, the PSU is located at the bottom, intakes through the bottom and exhausts through the rear. So a rear exhaust fan at the top is advisable to exhaust air from inside the case.

Ah ok, I can see the bottom intake holes on the photo now. Ive looked at that second case again and it comes with the rear fan. So I guess thats ok, and I'd just buy a front intake fan to go with it.


Ok so that seems like I have a solution then whichever case I go for and I understand how it works much better now I think.

Although still not sure how I control 2 case fans off the one motherboard header if you can explain that, would be great.

 

[Danny75]

Ah I see. This is the one that comes with the Fractal case:

https://www.overclockers.co.uk/super-flower-fx-450w-80-plus-bronze-power-supply-black-ca-035-sf.html

But this kind of put me off it compared to modular PSUs:

The SuperFlower Bronze are decent quality (for Bronze). Other decent ones are EVGA Bronze and XFX. The others in that price-range (below £50) are either lower quality or unknown for me.

Especially if the PSU is top mounted - where would all those cables go? Also not really sure how many of these I'll use?

On a 500W-ish PSU you will be using most of the cables anyway. Maybe just 1 or 2 you won't need. Modular is more helpful when you have a higher-wattage PSU with a lot more cable options. For example, the SuperFlower Bronze 450W has the following:

Connectors
- 1 x 20+4-Pin ATX12V/EPS12V
- 1 x 4+4-Pin ATX12V/EPS12V
- 2 x 6+2-Pin-PCIe
- 4 x SATA
- 3 x 4-Pin-Molex

And you would need all of them except perhaps one of the two PCI-E cables, or neither PCI-E cable (depending on your GPU and power connector requirement for it). Zip-ties are your friend. Some cases allow for better/easier cable management than others, but once it's done it's done.

Although still not sure how I control 2 case fans off the one motherboard header if you can explain that, would be great.

While possible it's not advisable to control two fans off one chassis header (it's ok if you need to use two from one CPU or CPU_OPT header but the Chassis headers aren't usually as good). So to bypass having to use the motherboard header, and connect straight to PSU, I would recommend purchasing fans that include a 4-pin molex connector. Or if your preferred fans don't bring one, then purchase this sort of adapter allowing three fans to run off a single PSU molex connector:

My basket at Overclockers UK:

• 1 x BitFenix Alchemy Molex to 3pin x3 Fan adaptor 12V 20cm - Black= £4.99

Total: £7.73
(includes shipping: £2.74)
​

​

This allows connecting up to three fans with regular 3-pin connectors to a molex connector from the PSU.

 

[danlightbulb]

I understand that molex can provide the power to the fans, but how do they control for speed if they are only connected that way?

 

[Danny75]

I understand that molex can provide the power to the fans, but how do they control for speed if they are only connected that way?

There is no speed control when you don't connect to motherboard or fan controller. It'll run at 12v (or 7v or 5v there are molex adapters for those too).

Bear in mind that most case fans are designed to run quietly at 12v anyway, if they're any good. It's the CPU cooler fan variety (typically PWM) that have higher max RPM, more noise, and do need some motherboard control.

 

[danlightbulb]

Oh ok so I just leave the speed control then. Seems a shame not to use it though, if the motherboard has the PWM chassis fan connector.

Bottom left 4 pin connector:

Asus website:

"Fan Xpert
Dedicated CPU and case fan controls

Exclusive Fan Xpert ensures every fan achieves the best balance of cooling performance and low noise — and with our 100 series boards and their hardware-level 4-pin/3-pin PWM/DC mode for case fans, a simple BIOS adjustment lets you run your case fan in PWM/DC."

 

[Danny75]

Exclusive Fan Xpert ensures every fan achieves the best balance of cooling performance and low noise — and with our 100 series boards and their hardware-level 4-pin/3-pin PWM/DC mode for case fans, a simple BIOS adjustment lets you run your case fan in PWM/DC."

Asus have made inaccurate claims in the past about their chassis fan headers being PWM, when they weren't true PWM. So I'm not sure whether they finally fixed that or not, or which motherboard it is.

Also, the DC option on the chassis header allows for some limited speed control on regular 3-pin fans too. In my opinion enough control for case fans.

You could try connecting a PWM fan there if you like. Or a plain 3-pin fan (it will connect to the 4-pin header too). And use molex for any extra fans required. Just make sure the PWM fan isn't static-pressure optimized (for CPU cooler heatsink/rads) instead of CFM-optimized (better case airflow) because PWM fans tend to be the former. But in my experience, all the speed control in the world won't make a poor fan good, because you can lower RPM for less noise and then get hardly any air being pushed, or max RPM for airflow but it's noisy. The other thing is the constant spinning up and down of a PWM case fan/s with every little CPU spike, when there's no need to, will tend to increase noise levels not decrease them. Unless you set them to a fixed speed.

 

[danlightbulb]

ok thanks. so it seems then that some larger, slow moving, quiet case fans permanently running at 12v would be the best solution and not bother with the PWM complexity. Makes sense. Molex it is, and looking for a case with 120mm front and rear now.

 

[danlightbulb]

Hi again. Silly question of the day probably but...

If i connect case fans via molex directly to the psu, then will they turn off when the pc itself is off (but the psu switch at the rear is still on)? Where is the feedback from the computer to the psu to enable this to occur?

 

[henson0115]

yes the fans will turn off when the pc is switched of in windows, but the psu switch is still set to on