Quiet Fans, your views and Recommendations

[SmoulderingCircuits]

The fans that came with my NZXT case were near on silent and I'm pretty sure they were at 12v, they aren't the best fans, but they certainly provided a light breeze, albeit not a hurricane as I prefer

 

[Scoob]

The fans that came with my NZXT case were near on silent and I'm pretty sure they were at 12v, they aren't the best fans, but they certainly provided a light breeze, albeit not a hurricane as I prefer

It's a balancing act as always I reckon.

You get some fans that work great at 100% and are fairly quiet...that's great.

You get another set that perform the same but at 50% - you've got a little headroom to play there.

My fans are a little too noisy at 100% certainly, but they're not often at 100% unless I'm stress testing when I welcome the extra cooling & accept the additional noise.

SLIZER is after quiet fans period, so I guess the former option would suit him well.

The more information we can gather the better, hopefully SLIZER will post back soon, maybe he'll be keen to start collating some of the information...

Cheers,

Scoob.

 

[Lollipop]

I think the reason many people(including myself) buy Noctua fans is that we know they work...

 

[Scoob]

I think the reason many people(including myself) buy Noctua fans is that we know they work...

Yep, no better reason than that!

Not used them myself but I'm aware they are highly regarded.

I'd never heard of Alpenfohn, actually can't remember where I heard of them, but have been pleased so far.

Scoob.

 

[Stryker64]

Some good recommendations on this thread for fans. I think the consensus is that ALL fans are pretty damn loud at full whack - assuming they're actually moving a useful amount of air of course!

Modern fans don't really suffer from actual fan noise as such (unless something is failing/worn) just the noise of the air-flow. Obviously the smoother this air-flow the better for both noise levels and cooling, however the nature of a "choppy" fan will always be exactly that, choppy air flow.

I'm not sure how much the various fin designs really help, nor the new "wing boost" stuff some are using now. I've gone from fairly basic fans (cheap as you can get) which were reasonably quiet at 50% and noisy at 100% but didn't shift much air, to a decent fan that shift more at 50% silently than the cheap ones did at max with a lot of noise. This suggests that these new fin designs really do make the air smoother as they are in the SAME application (rad/grill/whatever) and are pushing air through the SAME restriction, yet still manage to be quieter.

I've not done any real scientific testing, just jumped from cheap to good fans. Oh, the good fans ultimate ability to shift air tends to be quite high, useful if you don't mind the noise and also good as they still shift a useful amount at lower rpms.

Cheers,

Scoob.

The fan shape affects how much air the fan can shift per revolution, which is why some fans are at 1800RPM can have twice as much CFM as some other brands, so the fan shape affects volume of air the fan can shift. Another important thing to consider is how smoothly the air moves over the blade, which is why you can get these really weird shapes and notches in the fans because they are designed to reduce vibrations and drag caused by the fan blade. By reducing vibrations and drag, the noise will also go down. If you had a perfect, constant stream of air, not matter how fast the wind is travelling it would be perfectly quiet, assuming the wind going over your ears doesn't induce vibrations, drag causing noise.

Due to vibrations that are caused by the drag it can also create resonance, which is why fans can seem quiet, yet once you get to a specific voltage the noise suddenly picks up and it dies down once you go past that limit. A good example of resonance amplifying the affects of air flow is the Tacoma Narrows Bridge.

http://www.youtube.com/watch?v=j-zczJXSxnw

 

[yassarikhan786]

The fan shape affects how much air the fan can shift per revolution, which is why some fans are at 1800RPM can have twice as much CFM as some other brands, so the fan shape affects volume of air the fan can shift. Another important thing to consider is how smoothly the air moves over the blade, which is why you can get these really weird shapes and notches in the fans because they are designed to reduce vibrations and drag caused by the fan blade. By reducing vibrations and drag, the noise will also go down. If you had a perfect, constant stream of air, not matter how fast the wind is travelling it would be perfectly quiet, assuming the wind going over your hears doesn't induce vibrations, drag and causing noise.

Due to vibrations that are caused by the drag it can also create resonance, which is why fans can seem quiet, yet once you get to a specific voltage the noise suddenly picks up and it dies down once you go past that limit. A good example of resonance amplifying the affects of air flow is the Tacoma Narrows Bridge.

http://www.youtube.com/watch?v=j-zczJXSxnw

Some very good information there. The fans on my obsidian 650d had a slight buzzing at medium and low settings and when I set the fans on high via the fan controller the buzzing would disappear. When I got a fan controller, the buzzing noise I heard totally disappeared.

 

[Scoob]

[snip]

Yep, nicely put...also explains why my PC ended up in the lounge when I'm sure I left it in the 3rd bedroom...

Fan design is definately moving on...I was very impressed by my Alpenfohns, though I generally only bought cheaper fans previously so have little experience.

Scoob.