SPCR's Fan Roundup #4: 120mm Fans II

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FANDER FX-120

Ambient noise at the time of testing was 18 dBA.

Brand Fander Power Rating 0.18A
Manufacturer Xinruilian Airflow Rating 31~67 CFM
Model Number FX-120W RPM Rating 700~1,400 RPM
Retail Availability Limited (Europe) Noise Rating 14.9~23.7 dBA
Bearing Type Sleeve Header Type 3-pin & Molex Adapter
Hub Size 1.87" Starting Voltage 5.0V
Frame Size 120 x 120 x 25 mm Number of Samples 2
Voltage
Noise
RPM
CFM
Power
12V
26 dBA@1m
1400 RPM
46 CFM
1.21W
9V
22 dBA@1m
1040 RPM
32 CFM
0.90W
7V
20 dBA@1m
770 RPM
22 CFM
0.71W
5V
<18 dBA@1m
480 RPM
14 CFM
0.52W
@25 CFM (7.7V)
21 dBA@1m
840 RPM
25 CFM
0.86W
May 5, 2008
The updated airflow results here are the result of improvements in our testing procedures. They are more accurate than the original results above, but they are not directly comparable. Please compare these only with fan reviews published after May 5, 2008 — or ones that have updated results published in a box like this one.
12V
26 dBA@1m
1400 RPM
39 CFM
1.21W
9V
22 dBA@1m
1040 RPM
27 CFM
0.90W
7V
20 dBA@1m
770 RPM
20 CFM
0.71W
5V
<18 dBA@1m
480 RPM
11 CFM
0.52W
@20 CFM (7.0V)
20 dBA@1m
760 RPM
20 CFM
0.71W

The last Fander model we saw made quite an impression. Though we'd never heard of Fander before, this small Polish company produced a fan worthy of recommendation over any of the other 92mm models we saw. It did this by being both quiet and flexible, with an excellent noise signature and a built-in, variable speed fan controller. On top of that, it was rated for long-term use with an MTBF of 80,000 hours.

Naturally, we expect great things of the 120mm version, which is more or less the same as its smaller cousin. And, sure enough, when we powered it up for a casual test, it sounded just as good. It came with the same fan controller, giving it an operational range of 590~1400 RPM without requiring any modding at all. And, just like the 92mm version, it is rated for a high MTBF of 80,000 hours.


External fan controller not required.

Fast forward a few weeks, and we were finally ready to run it through some more rigorous testing. However, when we powered up the fan this time, it had developed a distinct chuffing that ruined its formerly smooth noise signature. The rhythm and volume of the chuffing varied considerably depending on the orientation of the fan, but the problem was too prevalent to get rid of just by adjusting the fan's position. Both of our test samples were affected, yet we could find no reason why the fans should suddenly develop this problem. We can only conclude that our rough handling somehow damaged the bearings.

Without the chuffing the noise was smooth and quiet enough to become inaudible below ~6V (roughly the same as setting the controller to minimum). Like the 92mm version, the noise character was very similar to the equivalent Nexus fan, which is to say, among the best we've heard.

The FX-120W certainly has the potential to be one of the top 120mm fans. With an undamaged sample, the wide speed range and control offered by the fan controller give it more flexibility than almost any other fan we can think of. On the other hand, if our two damaged samples are anything to judge by, the FX-120W may not be durable or consistent enough to beat out the other contestants in the field.

Noise Recording

ENERMAX MARATHON UC12EB

Ambient noise at the time of testing was 18 dBA.

Brand Enermax Power Rating 0.20A
Manufacturer Enermax? Airflow Rating 44 CFM
Model Number UC12EB RPM Rating 1,000±10% RPM
Retail Availability Yes Noise Rating 17 dBA
Bearing Type Enlobal Header Type 3-pin & Molex Adapter
Hub Size 1.77" Starting Voltage 6.6V*
Frame Size 120 x 120 x 25 mm Number of Samples 1
Voltage
Noise
RPM
CFM
Power
12V
28 dBA@1m
950 RPM
25 CFM
0.53W
9V
20 dBA@1m
710 RPM
18 CFM
0.45W
7V
20 dBA@1m
540 RPM
14 CFM
0.39W
5V
~19 dBA@1m
340 RPM
9 CFM
0.35W
@25 CFM (12.0V)
28 dBA@1m
950 RPM
25 CFM
0.53W
May 5, 2008
The updated airflow results here are the result of improvements in our testing procedures. They are more accurate than the original results above, but they are not directly comparable. Please compare these only with fan reviews published after May 5, 2008 — or ones that have updated results published in a box like this one.
12V
28 dBA@1m
950 RPM
22 CFM
0.53W
9V
20 dBA@1m
710 RPM
16 CFM
0.45W
7V
20 dBA@1m
540 RPM
11 CFM
0.39W
5V
~19 dBA@1m
340 RPM
6 CFM
0.35W
@20 CFM (11.3V)
28 dBA@1m
860 RPM
20 CFM
0.50W

One of the methods fan makers like to use to set their fans apart is to invent a new bearing type that is better than the traditional ball or sleeve bearings in some way. Most of the time, what's new is not the whole bearing but an improvement to some aspect of one of these two traditional designs (see Global Win's Nanometer Ceramic Bearings above). Enermax' Enlobal bearing is different. While it does share some traits with other bearing types, it stands apart from ball or sleeve bearings in a very fundamental way.

A bearing is designed to reduce friction between moving parts. Ball bearings do this by letting the parts roll on balls between the two parts, like wheels on a car letting the car roll forward without dragging on the ground. Sleeve bearings achieve the same thing by using a liquid between the two parts instead of solid balls — usually some kind of oil. This is like putting soap and water on a plastic sheet in the summer so you and your kids can slide down a hill.

Neither of these two examples apply to the Enlobal bearing, which uses a magnetic field in place of balls or oil. The Enlobal bearing is like a maglev train, in which the train is suspended on a magnetic cushion above the track, with only air between the two. Thus, friction between the moving parts is greatly reduced, since most of the time they are only in contact with the air, not each other. (That said, it is worth pointing out that at least one SPCR user has found that oiling the Enlobal bearing improved both vibration and noise dramatically).

The advantages of reduced friction are not hard to recognize: Less wear, reduced power requirements, less heat produced — and less noise. And, indeed, these are exactly the benefits that Enermax uses to sell the fans that use Enlobal bearings, including the Marathon that we looked at. The question is, how much do these theoretical benefits actually come out in practice? Have Enermax' engineers done a good job implementing the technology? Is it cost effective?

All of these are open questions, and not all are easy to address in a short review. For example, we cannot evaluate longevity or reliability, and Enermax' documentation conspicuously omits any hard numbers in this respect. Even a ballpark MTBF number would be welcome here. What we can examine are things like power, airflow and noise, and our hands-on review showed the Marathon to be unusual in a number of ways.

One things that surprised us initially was how little power it required — and how little the power consumption changed when we adjusted the input voltage. In fact, it required less power per rotation than any other 120mm fan we've tested — and not by a small amount! This stands to reason; with less friction to deal with, the fan's electric motor would not need to work as hard.

The quality of noise behaved similarly: It was low and changed very little with speed. This is markedly different from how fans usually behave; as a general rule speed and noise are strongly correlated, but the Marathon varied more based on listening angle than rotation speed. Unfortunately for the Marathon, it happened to be loudest at the angle that we typically measure from — 45° off the exhaust side — so our noise measurements and recordings are worst case, not typical. At this angle, the noise was a constant droning hum. Instead of becoming louder when the fan speed increased, the noise became rougher and more intrusive. In addition to the drone, a pure tone — most likely the sound of the blade assembly resonating — could be heard. At full speed, this resonance dominated the noise signature, but turning the fan down by even one volt dropped the tone drastically.

The best position to listen to the fan was directly beside it. From here, the Marathon was more or less inaudible below 9V (!), and even at 12V the pure tone did not distract too much. If we could guarantee that the fan was only heard from this position, we would offer it our wholehearted endorsement. But, thanks to the hugely directional noise pattern, the best we can say is that it might be worth experimenting with.

The fan exhibited a couple of other oddities as well. For reasons that never became apparent, the Marathon did not move as much air per rotation as many of the other fans we tested. Like the Arctic Fan 12L, the Marathon seemed to lag about 5~10% behind the airflow produced by other fans. But, while the Arctic Fan could probably attribute this to its frameless design, the Marathon doesn't have this excuse. While this isn't a large difference, it does bear thinking about and perhaps also some further testing at a later date.

Another oddity was the way the Marathon started up. Given a sudden burst of voltage (our usual method for testing starting voltage), the fan started reliably at 6.6V. However, if the voltage was increased gradually, the fan wouldn't start until a full 12V was reached. This could pose a problem if the Marathon ever stalls when undervolted. When the fan was stopped forcibly, it had trouble restarting unless the input voltage was close to 12V.

All in all, the Marathon (and presumably Enermax' other Enlobal fans) is a very interesting fan, but until some of its quirks are worked out, it won't stand out in the crowd as much as Enermax might like. For us, the biggest issue was the highly directional, resonant pure tone that made judging the noise character so difficult. Perhaps Enermax would do better to choose a less resonant (read: non-transparent) material for the blade assembly? However, it's worth pointing out that other users have had issued with vibration and quality control. It may be that fixing these issues is as simple as lubricating the bearing a bit, but we can't recommend a product that requires maintenance out of the box. Like the SilenX Ixtrema Pro, it is worth experimenting with, but hard to recommend unconditionally.

Noise Recording

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