be quiet! Shadow Wings 2 doesn't seem to exhaust much air

[King Mustard]

I have:

• a Silverstone PF240-ARGB AIO CPU cooler (top of case)
• 2x Bitfenix Spectre Pro PWM (140mm, 122 CFM, 500-1800 RPM, PWM, HSP) (front of case)
• a be quiet! Shadow Wings 2 (120mm, 39 CFM, 450-1100 RPM, PWM) (rear of case)

Full system details here (includes photos)

Whilst the Bitfenix fans seem to push quite a bit of air, even at 20% speed, the be quiet! fan doesn't seem to push much air out of the back of my case, even at 100%.

Granted, it's very quiet, but perhaps it's the wrong choice for my setup?

[[GSV]Trig]

You say it doesn't push much air vs the Bitfenix fan, given one is 122CFM and the other 39CFM, that would explain it...

What temps are you hitting in the case, how much air it moves, and how loud it is arent the point surely?

[cptwhite_uk]

Just get Noctua NF-A12x25, they push air and the noise profile is excellent. Pricey, but worth it. If you want to be cheap then Arctic Cooling P12 PWM PST are also excellent fans for the price (around £7-8 typically).

[Corky34]

Is the radiator using the two Bitfenix intake fans on the radiator up front? Or is the radiator for the AIO mounted in the top with the fans that come with it? If it's the latter are the radiator fans blowing out the top or drawing air in from the top?

[King Mustard]

You say it doesn't push much air vs the Bitfenix fan, given one is 122CFM and the other 39CFM, that would explain it...

What temps are you hitting in the case, how much air it moves, and how loud it is arent the point surely?

Temperatures are rather poor. I think you're right in comparing the CFM of the two. I may need to buy a new fan that can extract more warm air out of the case.

Just get Noctua NF-A12x25, they push air and the noise profile is excellent. Pricey, but worth it. If you want to be cheap then Arctic Cooling P12 PWM PST are also excellent fans for the price (around £7-8 typically).

I shall look into them, thank you!

Is the radiator using the two Bitfenix intake fans on the radiator up front? Or is the radiator for the AIO mounted in the top with the fans that come with it? If it's the latter are the radiator fans blowing out the top or drawing air in from the top?

The radiator (up top) uses the fans that the AIO itself came with.

[Corky34]

TThe radiator (up top) uses the fans that the AIO itself came with.

If they're exhausting air from the case i wouldn't worry to much about what the rear fan is doing, not that CFM numbers can be compared between manufactures (they often test CFM differently), but with the two fans on the rad being roughly 94 CFM and the fronts being roughly 122 CFM the rears 39 CFM is probably only doing some localised exhausting of air.

IMO, depending of how you set the fan curves, most air will be coming in the front and going upwards towards the AIO fans and out the case.

[Iota]

If they're exhausting air from the case i wouldn't worry to much about what the rear fan is doing, not that CFM numbers can be compared between manufactures (they often test CFM differently), but with the two fans on the rad being roughly 94 CFM and the fronts being roughly 122 CFM the rears 39 CFM is probably only doing some localised exhausting of air.

IMO, depending of how you set the fan curves, most air will be coming in the front and going upwards towards the AIO fans and out the case.

Indeed. Assuming all CFM figures are tested in the same way for the 3 completely different sets of fans, which is why I tend to stick to just one manufacturer of fans instead of mixing. From the sounds of it if the temperatures are not ideal, then the setup is producing negative air pressure. I've always aimed to produce positive air pressure in my cases, which has always helped keep temperatures in check.

Assuming 188CFM (94CFM x2) + 39CFM = 227CFM exhaust (depending on push or pull configuration on the AIO some of the 188CFM will be lost), and a max of 244CFM on the intake the potential is there for negative air pressure. Perhaps instead of just going out and buying new fans right away try adjusting the fan profiles to produce positive air pressure and see where it leaves the temperatures? You would ideally have the front fans pulling in more air than is being exhausted (creating positive air pressure to push air out quicker), the fan profiles on the AIO and rear exhaust shouldn't be so fast to ramp up, but the intake fans should ramp up quicker to draw in more air.

Try adjusting it first.

[King Mustard]

Indeed. Assuming all CFM figures are tested in the same way for the 3 completely different sets of fans, which is why I tend to stick to just one manufacturer of fans instead of mixing. From the sounds of it if the temperatures are not ideal, then the setup is producing negative air pressure. I've always aimed to produce positive air pressure in my cases, which has always helped keep temperatures in check.

Assuming 188CFM (94CFM x2) + 39CFM = 227CFM exhaust (depending on push or pull configuration on the AIO some of the 188CFM will be lost), and a max of 244CFM on the intake the potential is there for negative air pressure. Perhaps instead of just going out and buying new fans right away try adjusting the fan profiles to produce positive air pressure and see where it leaves the temperatures? You would ideally have the front fans pulling in more air than is being exhausted (creating positive air pressure to push air out quicker), the fan profiles on the AIO and rear exhaust shouldn't be so fast to ramp up, but the intake fans should ramp up quicker to draw in more air.

Try adjusting it first.

The problem is, the 2x Bitfenix Spectre Pro intake fans are really noisy, and I like a quiet system. When they hit 25%, they're quite audible, which doubles as an issue as there are two of them. So I try to keep them limited to 20%.

As the exhaust fan is so quiet, I tend to run that at 100% all the time, as I can hardly hear a difference between 100% and, say, 30%.

How about this as an idea?

• Keep the two intake fans as they are (at 20% each at all times)
• Change the puny be quiet! exhaust to a Noctua NF-S12A (and run it up to the level it's audible, which I'm sure will still perform better than the be quiet! fan)
• Make the radiator fans pull air in through the radiator, instead of push.

That way, all air will be exhausted through the rear.

Like me after a curry.

Thoughts?

[Corky34]

It's difficult to advise on fan setup IMO as people have different things they want to prioritise, temperatures they're comfortable with for the GPU, CPU, inside the case, noise, dust, and if they want RGB fans on display, so you'll probably never get a this is the best setup type answer.

Having said that some things to think about: Maybe try the radiator mounted in the front with the fans either pushing through the radiator or pulling air through, pushing through means the fans are closets to the front/outside so you can see the RGB but it also means the noise is closer to your ears with little in the way to block that noise. With the radiator closest to the front/outside you get the opposite effect, the radiator blocks the RGB but also reduces the noise a little.

Then you have to choose things like if you want cool fresh air going to the radiator first and dumping warm air into the case or the warm air from inside the case being used for the radiator before existing. Add to that the whole positive negative pressure argument and things only get more complex.

To give you an idea i personally don't care for noise so idling my CPU hovers around 55°C, the chipset is around 48°C, and various system read point range between 35°C to 40°C. IIRC under sustained load the CPU ranges between 65-70°C and the insides reach 50°C odd.

[Iota]

The problem is, the 2x Bitfenix Spectre Pro intake fans are really noisy, and I like a quiet system. When they hit 25%, they're quite audible, which doubles as an issue as there are two of them. So I try to keep them limited to 20%.

As the exhaust fan is so quiet, I tend to run that at 100% all the time, as I can hardly hear a difference between 100% and, say, 30%.

How about this as an idea?

• Keep the two intake fans as they are (at 20% each at all times)
• Change the puny be quiet! exhaust to a Noctua NF-S12A (and run it up to the level it's audible, which I'm sure will still perform better than the be quiet! fan)
• Make the radiator fans pull air in through the radiator, instead of push.

That way, all air will be exhausted through the rear.

Like me after a curry.

Thoughts?

Maybe try the radiator mounted in the front with the fans either pushing through the radiator or pulling air through

If you intend to have the radiator fans pulling air in, you'll essentially be bringing warm air straight into the case. As Corky suggested it would probably be best mounted on the front in that scenario (if the PSU shroud in the case allows), with the Bitfenix fans mounted to pull air out at the top of the case. Your GPU temps may suffer though with warmer air being directed onto the graphics cards (which will also add to the noise profile).

The problem with keeping the Bitfenix fans at 20% is you're essentially only providing ~24CFM intake per fan, so you are not drawing in much cool air. Not sure why they're so noisy though if they're rated for 29.2 dB(A), even at 50% they should be pretty quiet? You could always swap those two out for something like the 140mm be quiet! silent wings 3 (15.5 dB(A)), they move less air at max speed, but if noise is the primary concern then you'll probably have to live with higher temperatures overall. Swapping the rear exhaust to intake will also help towards creating positive air pressure (not ideal!), leaving just the top fans doing the exhaust for the case.