Just ordered the following:
Alpenfohn Wing Boost PWM 140mm, 1100rpm
Akasa AK-195BL Ultra Quiet Emperor Blue - 140mm
Noiseblocker BlackSilent XK1, 140mm
Noiseblocker BlackSilentPRO PK-2, 140mm
Scythe Slip Stream 140mm, 800rpm
Noctua NF-P14 FLX 140mm Fan, 750-1200rpm

Will let you know how they work as a side panel intake (vertical mount) for my fractal 3000. Will be a micro review just to keep the knowledge flowing

Already tried (as a side intake):
- BeQuiet Silent Wing USC 140mm
- Thermalright X Silent 140mm
Both gave an annoying whine/whizz/buzz even at low voltage. Fail.

Ok here it goes:
Apparently a side intake fan is quite hard to find, if you want a quiet one. I think it has to do with vibration of the panel (not at hinges or "teeth" but the whole plate) and the backdraft banging into the intake mesh. Here is my impressuin and how it went (all tested at 7V)

Alpenfohn Wing Boost PWM 140mm, 1100rpm
Lovely build quality, I really liked the rubbery construction and the solidness. It did have the low pwm click at low voltage. Outside of the intake panel it was near silent and gave just a suble whoosh, in the frame it rumbled. Still, a lovely fan, great looks. I tried it as an extra front intake but it didnt add anything, but it was quiet, only a tiny bubbly sound. Take note: this is a 4 pin PWM fan and I'd think this is a great addition to that segment.

Akasa AK-195BL Ultra Quiet Emperor Blue - 140mm
Yucky cheap construction, Not quiet and not my cup of tea.

Noiseblocker BlackSilent XK1, 140mm
Dissapointing. Not so quiet in or outside the sidepanel. Started with a horrible noise that gradually dissapeared but never totally went away.

Noiseblocker BlackSilentPRO PK-2, 140mm
Wow, dead quiet outside the case, but noisy inside... Even as a front intake it was noisier than the Alpenfohn. I have no clue why. Looked lovely but as an intake it give a vibration sort of whine. As an extra front intake it wooshed too loud. Maybe it moved too much air? Also, the rubber square frame to fit on is a great idea but ended up as a big frustration. One of the most annoying assemblies in my computer life ever.

Scythe Slip Stream 140mm, 800rpm
Didnt start up at 7v :/ Next.

Noctua NF-P14 FLX 140mm Fan, 750-1200rpm
Once again, opening Noctua packaging, you instantly feel the crafstmanship. Installed it and it was... the quietest. I am not a fanboy but I ended up with 3 Noctua's in my case now. They just sound and cool the best, in my case (pun intended). I still hate the colour and the price, but they come up as a clear winner every time, no matter what other reviewers say.

Just to make the round up complete, the BeQuiet 140mm Silent Wint USC is doing a splending job as a top blowhole and all in all I am impressed with this fan. But alas, this one also didnt pass the side panel test.

Take note: every case is different, every compontent is different and every rig's layout is different. Just order a great bunch of fans, install them, listen with your own ears, experiment with voltage and placement and take your pick. RMA the rest for a refund. Also: too much fan will destroy your airflow. Don't go overboard, in my case the tipping point was 2 intake/2exhaust. More fans didnt add anything or gave higher temps.

So there you have it. Thanks for reading and cool luck on your personal silent cooling quest!

EDIT
Slight turn up for the books... Even the Noctua, the quietest of the bunch annoyed me in the end with the slight buzz. Therefor I went back to the Noiseblocker. That thing moves so much air but it caused even more resonance in the case, and I think the backpressure (because of the better airflow) moving thhrough the mesh gave too much noise. I even added extra sillicons moving it further from the side panel etc.. but alas it was too noisy in that position. Such a shame.

So I still had a Silent Wing in my desk. When I looked at the packaging I saw that it had an operating Voltage of min. 3,5V. So I downvolted it and gone was the noise. Of course I was worried about GPU temps now. But they are only 2 or 3 C higher. Therefor I downclocked my GPU a bit, but all in all the extra heat is no problem. I guess you dont a high cfm to get an airflow started. 3,5V on a 140mm will get it going also.

Hurray for low voltage operation!

I don’t know why no one’s replied, after 216 views Really useful info for anyone after a 140 fan The only other 140’s I’ve seen do well were the Thermalright TY-140 and the Prolimatech Red Vortex 14, which SPCR rated as 'noticeably better' than their reference Noctua NF-P14: http://www.silentpcreview.com/article1191-page5.html

Thanks for the feedback.

I have TY-140 running on my cpu cooler and it's a great fan indeed. Actually, switch it around as a side intake. Argh, why hadnt I thought of that before?

The side intake is a hard position to fill in my rig. For some reason it is resonating too much, eventhough I have fastened it with extra sillicons etc.

The Silent Wing is an excellent fan with a great construction. Let's see if it is better or worse than the TY140

Als, the TY 140 doesnt startup at 7v and at 12V it is way too noisy.

That's why I like the Silent Wings. Their low operating voltage is equeal to its startup voltage (3,5V). That is quite unique and very handy if you need it to run at a low static voltage.

Juat wanted to add my thanks for the reviews, always good to hear people's experiences.

martin

Just wondering if you could give your impressions on it at 12V, i mean all the others are 1000rpm+, im guessing most go down to 600-800rpm at 7V, so give or take would be similar?

TY! I've read up here so many times and I always though user experiences were so usefull. I'd decided to add my own.

It moves too much air at 12V. I briefly attached it to the side panel at that voltage but the airflow is to high. The suction generates too much noise. That was my general impression with most fans, including the Scythe (and others I used way before this round up): they're quiet when just holding vertically in your hand, but when mounted on a side panel either the airflow or the back pressure generates too much resonance. Low voltage/low flow was the only option for me.

Oddly enough, as an exhaust the fans were all quieter. Odd... and I wonder how everybody else does this?

Thanks for your impression on 12V, i have one running, and i agree in terms of airflow, it moves a lot of air for 800RPM, and i also agree into pulling air in is more noisy, still is good enough for me, i kinda want to try the Noiseblocker PK1 (the same as the one you tested just 700RPM, but to running it at 12V).

I have also a TY140, but im running it PWM, and the intel mobo starts it at 12V for couple of seconds while the bios loads and then pulls it down to 700RPM, where to me its very quiet. Sad that it didnt start at 7V, but i do find the new way to run with PWM very convinient to avoid starting voltages.

Thanks again for your run down and for your post impressions,

Here's my experience of 140mm fans just bit overall:

Sharkoon Silent 140mm system fan: Quite nice, no tonality. Slight growl heard from the hub very near. Tested Antec Three Hundred top fan vertical. Fan blades caused minimal vibrations but not enough to affect case.

NoiseBlocker BlackSilent XK-1: In Prolimatech Armageddon: No extra noises heard. Smooth and low, pleasant sound.

Sharkoon 140mm Silent Eagle 800 rpm: Slight grounding heard at the beginning of the fan. It went away. I wasn't able to hear extra noise over my System. Was tested vertical and horizontally on Prolimatech Armageddon.

Thermalright TY-140: Quite nice fan. Hefty, PWM, good amount air. Had some bearing growl when listened from few inch away. Nothing audiable over case. Was tested vertically on Prolimatech Amageddon with PWM control. My Motherboard (Msi P64A-C45) reported lowest RPM for it around 600 on cpu header.

Thermalright X-silent 140: My sample is nearly inaudiable even upclose. No growling. no tonality. Smooth and pleasant sound quality. Doesn't change when put on Prolimatech Amageddon. Tested on vertically and horizontally. Currently mounted horizontally on my Prolimatech Armageddon as it gives more clearing than TY-140. Edit: 8/27/2011: S-Silent developed ticking sound after couple of days. Ticking went away vertical but continues horizontal mount.

Antec TriCool 140mm: Blades were off blaance. Cause fan vibrate like insane on top exhaust when mounted horizontally. Vertically no issues with vibration. Had low growling and ticking.

Scythe Kaze-maru 1200 rpm : very smooth pleasant sounding fan. No extra tonalities. Has low starting voltage.

Scythe 140 Kama-Flex: Sony Fluid Dynamic Bearing. Smooth sounding. Very minor ticking heard from 1-2 inch range. My 800 rpm variant hasn't low starting voltage. Excellent fan horizontally on top exhaust. I haven't tried it yet on my Prolimatech Amrageddon. Edit: Placed on my Armageddon 8/27/2011. Currently horzintally mounted exhibits no audiable side sounds from 20 cm away. At 850-900 rpm's only sound you hear is air woosh.

However I haven't used these fans in primary system which is truly, quiet. I intend later when I have time to test these in quieter environtment and see if I have to change my so far experience.

I have been looking at the Shadow Wing PWM 140mm.

Can you please try that ? Please make sure to connect it to a PWM connector (4 pins) on the motherboard. PWM removes all the weird sounds coming from them. DC or normal DC Regulators won't work. Also please mount it with the included rubber gommets to remove vibration. It will hang in levitation on the side of the panel.

Please try it and let me know if it's not just the most silent thing you'll ever "hear"

I have it here and it suits me well.

I'm using a PK-3 (the high-speed version) as a top exhaust, so I would like to add my own two cents.

First, while installing the included gasket is a little annoying, I found it to be well worth it. Not only is it a highly effective decoupler, it significantly increases effective airflow.

Second, at its lowest speed, my PK-3 is quieter than a Nexus 120mm but moves a whole lot more air, and even at full speed that moving air is pretty much the sole source of the noise. I haven't noticed anything remotely resembling whine or vibration. However, all that air can make a racket if it's forced to go through too small a space, so restriction can be a problem.

Frankly, I'm surprised that you felt so negatively about the PK-2, which should be even quieter. IMO, the PK-3 is a good choice for mid- to high-power systems. You have to keep it on its lowest speed, but that shouldn't be a problem, as the only reason to turn it up is if you want to see your case take flight.

Was wondering if you've tried the Silent Wings 2 already - a newer version of the SW USC. They've received excellent (but very few) reviews...

edit: after quite a bit of reading it seems very likely the Silent Wings 2 are the same as the USC, except for new anti-vibration mounts.