An old, yet still-selling aerodynamic design. Despite being attributed with excellent properties, we dare to disagree. It’s not quite the ideal system cooling fan that the NF-S12B-redux impellers were historically famed for either. Yes, it is quiet—but without the “airflow”. By that logic—where low noise carries the utmost weight—one could quickly conclude that the best fan is no fan at all. “Zero” noise, but substantial airflow isn’t happening here either.
We’ve examined in detail the fans with which Noctua once made its mark for case cooling—the NF-S12B impellers are supposed to be optimal for system cooling. It’s true that these fans were released a long time ago, but they are still current, specifically in their “redux” form. The original (brown-beige) S12 variants (-1200, 800, or B-FLX) have been out of sale for a long time, but models derived from them are available, cheaper primarily due to the absence of the premium accessories Noctua includes with its more expensive fans. The NF-S12B redux-700 fans come only with self-tapping screws, which for many users is all they need.
A completely different impeller from those we’ve tested so far. Short blades at a steep angle, large gaps. These are the parameters meant to indicate high airflow with simultaneously low static pressure. Noctua doesn’t hide this fact—that static pressure is low—even in the specifications, and instead positions these fans for non-restrictive environments. That’s where they should be suitable. “Non-restrictive environments” here mean PC cases where the fans are meant to provide air circulation that doesn’t require high airflow, and low noise is the priority. They come close to that, since their maximum is only 700 RPM, which is exceptionally low. For system cooling, it’s just enough—provided there aren’t more attractive fans available with equally low noise levels.
What’s notable about the Noctua NF-S12B-redux-700 fans—as with all fans from the S12 series referenced above—is that their frames are still smooth, lacking the typical micro-optimizations Noctua gives its newer fans. However, the serrated blade tips are also unconventional, a feature Noctua has since moved away from. We don’t know the reason, but one thing is certain—different aerodynamic designs call for different aerodynamic elements—i.e., those leading to the highest possible airflow at the lowest possible noise. In this case, those elements are the serrated blade tips.
For completeness, we should highlight details about the bearings. They are SSO—the first generation of “self-lubricating” bearings that Noctua started using in its fans. The Mean Time Between Failures (MTBF) is advertised as over 150,000 hours. Another mention regarding the material used—both the impeller and frame are made from PBT.
The trailing edges of the blades are smooth, without additional modifications. The low noise is achieved primarily through low speeds, meaning a maximum of 700 RPM. This speed is evident even from the fan’s name (NF-S12B redux-700), which includes it.
You are already familiar with the fan variant we will focus on in our tests. Besides this one, there are two faster models with higher airflow—the NF-S12B redux-1200 and the NF-S12B redux-1200 PWM. Notably, only one of them features PWM control with a 4-pin connector. Our tested model can only be controlled via linear (DC) voltage. This starts from x V, corresponding to a speed of xxx RPM. The maximum specified, corresponding to 700 RPM, is 12.0 V—with some tolerance, of course. The cable? Long—approx. 40 cm. This is longer than on fans where cable extension via a supplied splitter is anticipated. Such an extension is not included with the Noctua NF-S12B redux-700, so a long cable is used directly, forming a fixed part of the design.
Please note: The article continues in the following chapters.
