These notes describe how to (nearly) silence the fan noise from the WiebeTech RTX220-QJ dual tray-free SATA hard drive enclosure, by replacing the rear 60mm fan with a top 120mm fan. Alternatively, one could follow these instructions to provide additional drive cooling for an unusually hot environment. In short, one blocks the rear fan vent, and removes the carrying handle to expose a larger opening on top.
This quiets the fan, but does nothing about the sound of the hard drives themselves. The RTX220 enclosure acts a bit like a musical instrument, amplifying the drive noises within. One could attempt to dampen this noise using the same adhesive foam sheets used to quiet computer cases. My solution is instead to use a solid state drive as my primary drive, and to unmount these external hard drives whenever possible.
I have owned various WiebeTech products for many years. They make desktop storage products of exceptional build quality and reliability, with over-the-top customer service. Their products are expensive, but I always return to their product line after issues with alternatives.
My primary computer is a MacBook Pro, with a 160 GB Intel X25-M internal solid state drive, following buying advice at AnandTech. For secondary storage, I have a 2 TB external drive, cloned to various other drives using SuperDuper!. My internal drive is silent, and all external drives are usually unmounted and asleep. I have scripts in /etc/periodic/daily and /etc/periodic/bihourly (set up by cloning and modifying com.apple.periodic-daily.plist) which mount and unmount external volumes as needed, calling SuperDuper!'s SDCopy and Time Machine's backupd-helper to perform backups. So usually, the only noise in my study comes from fans in external devices. For this reason, there didn't used to be any.
The RTX220-QJ is a spectacularly well-made and convenient piece of equipment. It doesn't divide time as definitively into BC and AC epochs as the move from floppies or to solid state drives, but now that I have one I can't imagine ever going back. In many environments, the SATA drives themselves will be louder than the RTX220-QJ internal 60mm fan. However, in my environment, the fan is unacceptably loud.
The fan included with the RTX220-QJ is a Sunon KDE1206PHV3, a 3000 rpm, 60mm fan rated at 15 CFM and 25 dBA. A fan of comparable CFM is necessary to prevent the drives from overheating; opening the RTX220-QJ top is not enough, although adding a sufficiently tall passive cooling chimney might work. (Think this through; Trombe walls tend to be two stories tall.)
One reasonable replacement fan, shown above, is the Scythe D1225C12B1AP-11 Gentle Typhoon. It is a 500 rpm, 120mm fan rated at 18 CFM and 5 dBA. It also has good static pressure; I swapped the highest rpm model in this series onto a cpu cooler, and noticed a significant overclocking performance improvement. What do they say for cars? People buy horsepower, but they drive torque. For fans, people buy CFM, but they drive static pressure. Much like a solar panel, there's a load curve describing the actual performance under varying conditions. CFM and static pressure are just different peeks at that curve.
DIY computer builders prefer large, slow fans, both because they are quieter, and because the remaining fan noise is at a lower, less obtrusive frequency. Here, the remaining fan noise is a faint clicking sound, inaudible if there are any other noise sources or if one is more than a foot or two away. This is common for very slow 120mm fans. One could use a higher CFM fan, but then the primary sound can become the flow of air through the drive bays. Within reason, this sound is actually pleasant. What constitutes noise is highly subjective; one could experiment with different fans here to find the most acceptable sound profile.
Another fan candidate is the Scythe SY1225SL12SL Slip Stream. It is a 500 rpm, 120mm fan rated at 24.5 CFM and 7.50 dBA. Some prefer this series over the Gentle Typhoon series. To my ear, this fan is a bit louder, although it settles down a bit as it breaks in. The air flow through the enclosure is still silent. Its plastic housing is a more closed design, so one might need to cut its housing to route the cable; if you do so, be careful not to sever any fan wires. For some reason this fan triggers my RTX220 fan warning light. Perhaps the warning threshold is set right at 500 rpm, in which case any fan rated at 500 rpm is right on the edge. The warning light is easily masked with black vinyl electrical tape, but masking it feels like a kludge. There is a good discussion of low rpm Scythe Slip Stream fans at Fan Roundup #5: Attack of the 120 Scythes. The 800 rpm Slip Stream does not trigger the warning light, but it is louder than either of these other fans. After these experiments, I settled on the Gentle Typhoon, which I cannot hear under most circumstances.
As an alternative to mounting a 120mm fan over the top opening, one could mount a 92mm or 100mm fan inside the top opening, or an outboard 80mm or 92mm fan attached to the rear fan opening using a fan adapter such as a Funnel 60 to 80mm Fan Adapter. However, 15 CFM is a very low CFM, and fan selection is best in 80mm and 120mm sizes.
One can slow fans down in various ways, such as using a Zener diode to drop the fan voltage. Doing so opens up a much wider selection of fans. Choose a one watt diode, and solder it into the red wire of a fan extension cable, with the diode band facing toward the power source, away from the fan. This will drop the voltage that the fan sees by the rated voltage of the Zener diode. For example, a 5.6V Zener diode will drop the 12V power source to 6.4 volts, which is a nice choice here for the Scythe S-FLEX SFF21E 120mm fan. Be aware that different fans have different minimum startup voltages.
The RTX220 comes with a recessed carrying handle, set into a rectangular opening on the enclosure top. (Earlier models differ.) The carrying handle unscrews easily, exposing the top opening we will use. Remove this handle, and put it out to pasture.
To slide the RTX220 case open, unscrew four screws from the bottom, and two screws from the back. Sliding the outside shell forward, the front display will remain attached by a cable to the rest of the unit, but we will have enough room to work.
Be extremely gentle in disassembly; the black surface of the RTX220 is easily scuffed, and these scuffs are not easily concealed.
Stop to admire the workmanship inside the RTX220. Even if one strives to channel Richard Feynman and take apart everything in sight, one rarely sees this build quality. Between first reboxing the RTX220 in horror at its fan whine, and unboxing it again in an attempt to mod it, I spend hours researching how I might make a unit like this for myself. I realized that I could never do this nice a job; I felt like a peasant from the Middle Ages, staring in disbelief at Roman architecture.
The included rear fan attaches to a fan header on one of the two rear bridge circuit boards. Observe the color coding while the fan is still plugged in, write it down or take a picture, and compare it to the above picture. Unplug the fan. Remove the fan and tape its outside-facing side with vinyl electrical tape to block the rear fan opening. Reattach the fan but don't plug it in. This fan will also serve as documentation for the fan header wiring pattern.
These fan headers are not standard case fan headers; they accept the slightly smaller JST XHP-3 connector housing and SXH-001T-P0.6 pins. It is easiest to convert to a standard case fan header using breadboarding jumper cables such as SchmartBoard 12" Jumpers. (One can also make jumper cables from scratch using e.g. female RS232 crimp pins, but these prepared jumpers grip very nicely.) Either attach one end of each jumper to a standard fan header, or cut the jumpers in half and solder jumper ends onto the three wires of the appropriate half of a fan extension cable or Y-adapter. Do include the yellow signal wire, to avoid triggering the RTX220 fan warning light.
Alternatively, WiebeTech is probably attaching the JST connectors in-house to the Sunon fans. If you ask nice when you place your order, they might be able to make a fan header conversion cable for you. There's also the option of cannibalizing the connector on the Sunon fan. I like reversible mods; cannibalizing is poor form.
Note that the fan wiring pattern is also not standard; the yellow signal wire is in the middle, rather than on one side like a standard fan header. Mark the jumpers unambiguously or work very carefully; if you have a heat gun and heat shrink tubing, you can correctly color code both ends of each jumper cable with 3/32" heat shrink tubing. This is particularly important if you use the headers that come with the SchmartBoard jumpers in place of a case fan header. A case fan header is idiot-proofed to connect in only one way, but the SchmartBoard headers are not.
Attach your fan header conversion cable to the top bridge circuit board, following the wiring pattern as shown. To be safe, you should confirm the correct wiring pattern for yourself, by studying the color coding on the supplied fan and your replacement fan. After all, you're taking sole responsibility for what happens when you apply power.
This retrofit is really just an excuse to introduce some nice hardwood. Hickory looks particularly nice against the black of the RTX220 case. One needs a 1/2" thick piece of wood, 5 1/2" to 6" wide and 7" to 7 1/2" long. One source of exotic hardwoods is a Rockler Woodworking and Hardware store. Lowe's or Home Depot is likely to at least stock 1/2" by 6" oak boards, as a specialty item.
If you need my advice cutting the fan hole, it would probably be safest to use a good jigsaw, or cut the hole by hand. After sanding, a freehand hole will look just fine. However, if one has other uses for 120mm fan holes (I vent my Linux box out a window in the heat of summer, for example), then a 4.5" hole saw drill attachment may be worth the investment. These are however very dangerous if not used in a drill press; they tend to kick wildly on first contact with the wood.
It is safest to combine a weak cordless drill with patience, to minimize this risk. One can also improvise a drill press effect, by swapping in a longer drill bit (find one with a flat spot matching that of the provided bit), and anchoring one's project onto a thick piece of wood. Two screws between the pilot hole and the hole saw itself will never contact spinning metal. Wear protective gear nevertheless, and brace the drill to the best of your ability; the hole saw can still kick on first contact, it just won't careen into your flesh. Practice on some scrap wood. Set the pilot hole very carefully. Off-center front-to-back won't show, but off-center side-to-side will show.
For ease of maintenance, the fan can be attached using 2" 8-32 machine bolts; there is neither room nor need for nuts on the underside. Drill holes for these bolts; I found it convenient to use the fan itself as a drill guide. Now sand and finish the wood fan plate. Oil finishes can weep, and anything that requires a brush and has to dry is a hassle. I like hand-rubbed paste wax finishes, which are pleasing to the touch within minutes.
Optionally, attach a fan grill over the fan. To isolate the fan from the RTX220 enclosure, one can use a fan gasket such as the Rubber Fan Silencer between the fan and the wood fan plate, and apply 3/16" by 3/8" weatherstrip foam tape (any hardware store) to the underside of the wood fan plate. Now the fan can be attached to your fan header. Dress the fan wires neatly inside the enclosure so that they don't rise up and get caught in the fan blades, and rest the fan assembly on top of the RTX220 enclosure. The machine bolts will protrude down just far enough to keep the fan assembly centered over the opening, and the weatherstripping keeps the fan assembly from sliding around.
Test first without drives inserted, so if your incorrect wiring job curls blue smoke, at least there is no loss of data. A 15 CFM fan will barely lift a sheet of facial tissue. The real test is copying a terabyte or two of data between the drives without triggering any warning lights.
I buy WiebeTech products directly from WiebeTech, for their stellar customer service. They back their products bought elsewhere, but offer a 14 day "no questions asked" return policy on direct sales.
In California I'm fortunate to be ten minutes away from a Fry's retail store, where one can find the materials for a first draft of any project like this. However, the ideal components generally have to be on hand or ordered online. Two big online electronics sources are Amazon and Newegg. Exotic fans and fan accessories are hard to find. A few specialized online sources for the DIY computer builder are: