Closer Look: Noctua NH-U12S
Well, no surprises here – at least at first glance. If it wasn’t for the trademark tan and brown color scheme, you could easily mistake the NH-U12S for any of the other various 120mm tower coolers available.
The NH-U12S sports (an above average) five copper heatpipes in a “U” shaped configuration. The base and heatpipes are plated with nickel, and the heatpipes are soldered to the heatsink fins to greatly improve heat transfer. The included NF-F12 fan could be considered Noctua’s secret weapon – just try finding SS02 bearings, AAO frames and a Heptaperf™ Impeller on another CPU cooler.
Wait – Hepta-what?? It looks like a normal seven-bladed fan (okay, impeller) to me – why all the fancy words? In short, Noctua uses fancy words because there’s some serious aerodynamic engineering behind the NF-F12 PWM fan. It’s worth it to take a moment and explain some of the features, because you’ll quickly realize why Noctua has garnered such a reputation for their fans.
First, the SSO2 bearing. SSO stands for self-stabilizing oil-pressure bearing. This bearing type combines an oil-based bearing that is stabilized by an additional magnet placed closer to the axis of the rotor. Not relying solely on the CNC milled brass bearing shell for stabilizing something that revolves 1,200 times per minute probably helps Noctua achieve a 150,000 hour MTBF for the fan, and that gets backed by a six year warranty – one of the longest I’ve seen in a rapidly evolving market like enthusiast hardware.
AAO stands for Advanced Acoustic Optimization, and describes the features Noctua added to the frame to reduce vibration and increase efficiency with respect to noise. To do this, they’ve integrated (silicone, I’m assuming) anti-vibration pads on all corners (the NH-U12S comes with an additional, thicker set of pads that can be swapped out on a second fan in a pull configuration) and a series of “steps” or ridges along the intake rim to rough up the incoming airflow (the smooth intake flow of air will get mixed up anyway by the blades – doing so a bit beforehand will reduce noise when that occurs). This Stepped Inlet Design has the side effect of increasing performance respective to a smooth curve when placed against an intake filter or other restriction. Noctua doesn’t stop there with their acoustic optimization though, as the inner surface of the frame is filled with “microstructures” that – well, perform science (It helps reduce the noise of the blades as they pass by while improving airflow – I’m assuming the effect might be similar to the use of dimples on a golf ball).
The NF-F12 doesn’t stop there with the engineering. Once the incoming airflow makes it past the Stepped Inlet, by the microstructures and through the Heptaperf Impeller, it hits the stator vanes which are placed at varying degrees from each other to help spread out the spectrum of noise from the air being “squished” (<–engineering term) between the blades and the guide vanes. The trailing edge of the eleven stator vanes have notches cut into them, which helps the split airflow merge back together over a short distance instead of crashing back together upon reaching the end of the blade/vane. These vanes combined with the Heptaperf Impeller are part of the Focused Flow™ tech, which straightens and improves the airflow after it goes through the fan (achieving higher performance and static pressure with less RPMs, and therefore less noise). If you want to read even more about some of the technologies that go into Noctua’s products, they have some extensive information available on their website along with some helpful diagrams that help explain some of their trademarked features.
Noctua sent an additional NF-F12 PWM fan for testing a push/pull arrangement. This is a twin to the fan included with the NH-U12S and replaces the previous NF-P series of fans. The included accessories are pretty substantial for a 120mm fan and should make sure you’re up and running quickly (and quietly). If you need even more noise control, an included Low Noise Adapter will restrict the RPMs even more. Honestly, the stock performance/noise ratio of Noctua fans in general are pretty stellar, but the option is still there if you need it! There’s a 30cm extension cable and a Y-adapter included as well for adding multiple fans or reaching those far corners of a case.