Results: Airflow through a hexagonal grille
Due to the atypical spacing of the mounting holes for its format, the new Noctua NF-A14x25r G2 PWM fans cannot be installed in 140mm positions as standard. You need a conversion frame for that, and one such frame was designed, made and sent to us by an HWCooling reader. So, we were able to simulate and test one of the most anticipated fans of recent years (NF-A14x25 G2 PWM) already now.
Results: Airflow through a hexagonal grille
Why is there a missing value sometimes? There may be more reasons. Usually it is because the fan could not be adjusted to the target noise level. Some have a higher minimum speed (or the speed is low, but the motor is too noisy) or it is a slower fan that will not reach the higher decibels. But the results in the graphs are also missing if the impeller is brushing against the nylon filter mesh. In that case, we evaluate this combination as incompatible. And zero in the graphs is naturally also in situations where we measure 0.00. This is a common occurrence at extremely low speeds with obstructions or within vibration measurements.
- Contents
- Fan through a frame?
- Results: Airflow through a plastic filter
- Results: Airflow through a hexagonal grille
- Results: Airflow through a thinner radiator
- What we have arrived at
Hmm, a supposedly top fan performing so poorly on plastic filter with a spacer… A possible explanation is that the adaptor seems a bit leaky on both sides, and the fact that the gap (between the fan and the adapter) is spaced away from the obstacle might have introduced a significant path of least resistance. This issue is less apparent on obstacles with less impedance (radiator and hex grill).
To validate whether the adaptor is working as intended, I would suggest testing the adapter on one or two other fans with anti-vibration pads (perhaps Noctua A14), at one or two noise levels, to see how much impact the adaptor will makes. Of course, if time allows.
There are more of those little leaks. They are also on the rounded sides (between the fan and the frame) and then also between the frame and the obstacle. Fiberflex 40D is a very elastic material and the shape of the frame is also shaped by the force with which it is attached to the fan or to the obstacle. A more rigid material with higher hardness would not be as pliable, would not flex as much, and the results might be better. It is hard to say by how much. We will be able to speculate on that after we know the results of the NF-A14x25.
Among 140mm fans, the airflow of the Noctua NF-A14x25r G2 PWM with the DIY frame through the filter is below average, but still always higher than the NF-A12x25. Note that the Toughfan 14 Pro is not much better and on the grille the Thermaltake fan is already lagging behind. Well, we’ll see, we’ll get to a proper conclusion in September. 🙂
The model already supports fan sizes ranging from 200 mm to 92 mm. Just keep in mind that it may perform slightly better without anti-vibration pads. Please take the code with a grain of salt, as I’m not a professional programmer. I would gladly accept your suggestions. Of course, you are welcome to modify and improve the code as you see fit.
Thanks for the follow-up.
A combination of a stronger material that would be less subject to deformation due to the screws (to keep the flexing of the frame as small as possible) and a hair larger hole (to accommodate the Noctua SID) would probably lead to better results. The question is by how much, it would probably only be to a negligible degree. I suppose the biggest improvement would be better sealing of the frame from both sides, as each gap reduces static pressure, but I wouldn’t see even that as dramatic in this case. The key to functioning on a radiator in my opinion is that there is a good amount of sealing at the corners. With these we already have an idea of what effect they can have on the airflow from the tests of different corners on the BeQuiet! Silent Wings Pro 4.
I was concerned about the strength of the narrowest point by the central opening. The cross-sectional thickness in this area is 3.5 mm, which I believe is a reasonable minimum (though the model allows shrinking this dimension to 3 mm). I didn’t want to exceed the standard fan size format, but increasing the main dimensions could provide greater strength. As for the material, it might be better to use something with a 60D hardness, which could also be a better option from a printing perspective.
Here’s a direct link to the archive containing the model for English-speaking readers.