As part of my radiator testing, I did purchase several sets of fans to experiment with. Since the Gentle Typhoon AP-15 did so well in a noise/cfm ratio in previous testing I had been curious how the higher speed GTs work in comparison. The AP-29 differs from the AP-15 in that it only has 7 blades as opposed to 9 and it also has a special and unique stiffening ring. I tried to make contact with Scythe about possibly sponsoring fans but my request was ignored and I could never make any sort of actual contact. The Titans are just something I found perusing SVC one day and had to have a set and also picked them for my radiator testing since they were cheap, in stock, and had a good RPM range.
Being without any sponsor, I’ll give myself a special thanks to MLL.org for sponsoring this test…:) I ordered the GT AP-29s from an ebay seller as it seemed to be the cheapest price shipped I could find. I also ordered the Titan’s from SVC myself since they were on sale for $10.99 and I was anxiously crossing my fingers I would find a good alternative to the GTs.
Gentle Typhoon AP-29
First thing to catch my attention is this fan comes only with 4 pin molex connectors, so you will need an adapter or to rewire it on your own if you need 3 pin. The fan doesn’t come with much more than standard self tapping case screws. It is built well though and heavy and more industrial in quality than your average 25mm fan.
Gentle Typhoon AP-15
For comparison purposes with the previous 1000-1800RPM winner, here is the AP15. The king of CFM/RPM from my previous rounds.
For comparison with a good but average noise level and more conventional 7 bladed fan, here is the Zalman ZM-F3. It what I consider a good average noise level fan at a great price. It also has a pretty good speed range so it’s a good one to compare with as well.
These are the fans I’m using for the radiator testing that were attempting to be low cost GTs. They look nice and actually do better than the Zalman at slower speeds, but things fall apart quickly at the higher speed range. The sample tested seemed to have some debris in the motor causing a bit of rubbing type noises from 1400-1800 and then a harmonic developed from 1800 up to 2300RPM. The debris would probably work itself over time and the harmonic may or may not be specific to the radiator test rig, but that’s what I got in this run.
The charts above include looking at a few variables independently.
Of primary value is the air flow vs noise level chart which is the most representative of radiator performance. It’s not perfect nor as good as actual thermal based testing, but I find it good “quick” simulation that allows looking at the full spectrum of possible undervolting conditions very quickly. It does however only represent noise “Level” and not “Quality”.
Chart 2 is just comparing RPM to noise and plots a similar response. The GTs are very good about keeping noise “Level” down to a minimum when mounted to a radiator and much the same using RPM between the 15 and 29.
Chart 3 is taking a closer look at how much air they push per RPM. This is where the GT 15s doing very well having a higher blade count without stiffening ring allows them to produce more air per RPM. General most fans produce the same amount withing about a 200-400RPM window though. Somewhat surprising though, the Titan despite it’s similar appearance doesn’t have the same flow/rpm advantage as the GT 15s. There is quite a bit more gap between fan blade and frame and slightly different blade pitch as well as how the back of the blade curves more than the GTs. The AP-29s do a bit better than average at slower speeds, but seem to loose all of that advantage from about 2000RPM on upwards which I suspect is mostly due to the stiffening ring causing turbulence.
The higher speed AP-29 does seem to follow in a similar trend (CFM per RPM) as the exceptionally low AP-15 did although I would say subjectively when listening to the videos side by side, the 15 is producing less motor noise and smoother in sound. The stiffening ring does seem to eliminate the resonance spikes that are present as specific RPM levels of the AP-15, so that’s a good thing although the CFM per RPM level is not quite as good as the 15 which is also probably due to this same ring. The range is a bit more limited on the lower end were 5V is basically starting at 1200RPM, but it makes up for that in it’s near 3000RPM maximum at 12V.
While it’s hard to find fault in the AP-29, I personally find noise levels beyond 2000RPM still to high for my taste despite the noise levels being significantly lower than your average fan and also find the noise quality of the GT15 better than the 29 at slower speeds so it is a bit of a compromise. I think more people would be better off with the slower speed 15, but the AP-29 does extend the fan power range for those needing similar GT quality in a higher speed flavor. As with pretty much all fans, you can’t have it all and extremely high speed fans generally struggle at slower speeds and the AP family is much the same there. The AP-29s are exceptionally good at 1800-3000RPM, but the AP-15s are still king of 1000-1800RPM levels.
The Titan Kukri’s do pretty well at slower speeds and they do have a more desirable white blade color, but they are not even in the same league regarding build quality as the gentle typhoons. On my particular test rig with radiator, I also had high speed harmonics and other not so smooth motor type noises as RPMs increase beyond about 1400RPM and particularly beyond 1800RPM. Not quite sure why but I suspect it’s the blades flexing since the plastic used is softer than that of the GTs and not as reinforced at the hub either. Overall a great fan for the price when operated at slower speeds, but the Titans are not at all outperforming or coming close in performance to the GT-15 in terms of noise level or noise quality in the 1400-1800 range. I would say they are better than average in the <1300-1400RPM level, but average to poor at higher speeds.