Fractal Fan Mod

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update 8/26/11
After a few weeks the Fractal is still very quiet. If I did it again I would mount all 4 standoffs with JB Weld. I estimate I could position the fan better and keep the mount more square this way.

In this post I’m going to detail a fan mod on my Fractal FX Standard. The mod makes the Fractal A LOT quieter! I’ll post before/after noise measurements, before/after cooling temperatures, detail the mod, list parts you’ll need, and give my rational for wasting your life and money.

The nuts and bolts of things are at the end of the post. Go there if you could care less about why.

Rational: As I’m going to say in another post I love my Fractal Standard. But one thing I don’t love is it’s loud fan. For a $1,100 unit (bought used) I wouldn’t expect fan noise to be an issue. And for many people it isn’t an issue. For example, you would never hear this fan over any realistic practice level. And since no mics are needed to get a great sound out of the unit fan noise is moot. But my space is a very quiet mixing room. I can hear my hard drives, my computer case fans, the faint buzz/hum of my Bryston B2 power amp into my Mixcubes. Guess what? the Fractal fan is louder then all those combined (no science was used to assess the truthfulness of this statement). But seriously, the Fractal fan is loud. It’s a ball bearing 60mm fan that rotates at 3600 rpm and pushes  15.5 cfm of air. Tiny jet engine.

At first I was a little confused why the Fractal would have a fan at all. Just like my computer it has a processor with a heatsink. But unlike my computer the unit is sealed so no exchange with outside air can occur. The Fractal fan just blows air down on the heatsink and averages out the internal air temp. How much difference could this make?

I took some temperatures with an infrared thermometer. First I programmed a preset that got the Fractal running at full (96%) cpu usage. Then I let the unit warm up for about 20 minutes and started taking readings. The difference between the stock fan and no fan at all was about 26° F. Highest temp with the fan was 96° F. Highest temp with no fan was 122° F. If you decide to nerd out and take some temperatures make sure you give the unit at least 20 minutes to warm up. I think an hour is even better since it takes a while for all the components to warm up and reach a stable internal air temp.

So the stock fan does cool things quite a bit. But to me 122° F isn’t all that hot. Mind you the heatsink on my graphics card with no fan was 137° F and my hard drive was 103. My guess is the Fractal would do fine with no fan except in extreme conditions. But isn’t that what engineering is about? A factor of 10 safety margin. I’m not advocating removing your fan. For one it would void your warranty. And consequences of a melted Fractal don’t seem to outweigh the benefits.

A larger fan: My very first thought was to replace the 60mm fan with a larger 80mm fan. 60mm fans have to work very hard to push air. A larger fan could spin less to push the same amount of air. There are far more quiet 80mm fans then 60mm fans. A 80mm fan would likely be deeper putting it closer to the heatsink (you have to know the layout of the Fractal to appreciate this). I assume this would cool better.

All this sounds good but as usual things aren’t that simple. The stock fan directs a pretty strong stream of air down on an equally small heatsink. A larger fan might move the same amount of air (cfm) but not direct it as well on the heatsink.

There are lots of other things you can consider. Static pressure and the larger dead zone in the middle of a larger fan. But who cares? My infrared thermometer will tell me the reality of things.

Before/After Noise: Ever notice how fan noise stats are pretty much meaningless? There seems to be no standardized way to measure this across the industry. Manufacturers are “generous” with their ratings. And 30db of whine sure is more annoying then 30db of pink noise.

So I decided to just set up this mic and record all fans inside the unit. Everything here was held constant except the fans. Take a listen. Here is the stock fan, the Coolink SWiF2 800 80mm with and without rubber washers, and the Nexus SP802512L-03 80mm. As you can hear the rubber washers don’t make much difference. For a fan that has a rep for being quiet this Nexus sure wasn’t!

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Fractal fan mod01 stock fan by cporro

Fractal fan mod02 coolink by cporro

Fractal fan mod03 coolink rubber washers by cporro

Fractal fan mod04 nexus by cporro

The big take away for me is that fan speed has a direct relationship to noise. Here the slowest fan (Coolink) is by far the quietest. It also pushed the least amount of air but I’m ok with that so long as my infrared thermometer readings are decent.

The other thing that occurred to me: This particular setup is more prone to noise then normal. You have a fan mounted to a large metal panel. Turning the panel into essentially a speaker. This type of set up would not occur in a computer. The fan would either mount to something that does not vibrate well (CPU) or mount over an opening.

Before/After cooling: After shooting the heatsink in various places I determined where it was hottest. The total variation was only about 4° F anyway. I took a lot of readings always logging the ambient temp (usually about 70° F). Here is how it boiled down.

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The stock fan cooled to about 98° F. The Nexus (Nexus SP802512L-03 80mm Case Fan) to 98° F. The Coolink to 102° F. As I said earlier with no fan the unit got to 122° F.

Given my belief that the fan is just a precaution to begin with I am comfortable using the very quiet Coolink.

You will need:

  • Quiet 80mm fan, 3 pin. (I used a Coolink SWiF2 800 80mm case fan) This fan is 25mm deep which is not an issue unless you use a lot of washers.
  • JB Weld (they make a few different types. The original seemed best suited)
  • Sand paper to prep metal for JB Weld.
  • 4 standoffs (Hex Standoff, Female-Female, Aluminum, Screw Size 6-32, Hex Width 1/4 In, Length 1/2 In, Thread Length 1/2 In) grainger.com You could use your stock standoffs but the new mounts are permanent. If you go back to a 60mm fan you will need to buy some more.
  • machine screws (6-32, 1 1/4″) from a hardware store. Better to get the ones where the head mounts flat not beveled. Remember the bottom of the new standoffs will have a bit of JB Weld on them so the screws should not go all the way to the bottom of the standoffs.
  • Washers. You may be able to get away with not using these. I like them because they keep the screws from jacking up the fan chassis and distribute pressure evenly.
  • Rubber washers. Optional. I thought these might decouple the fan better from the Fractal chassis making it quiet. In practice is seemed to shift the noise form one area of the spectrum to another. Kinda like noise cancelling headphones.
  • Infrared thermometer. Only needed it you like to check your work. Also good for rating the temperature of hot chicks. Wha? Only 94°? Must be wrong.

Mod:

  1. Remove the top of the Fractal. Caution: the fan is mounted to the top panel of the Fractal but it plugs into the board on the bottom of the Fractal. Don’t just pull the top panel off or you will rip the fans power wires right out of the board! After you remove the 10 tiny screws slowly lift the top panel. Then peak inside and see how things are connected.
  2. Remove the stock fan.
  3. Prep the top panel for JB Weld. I roughed up the areas where the new mounts will be. I also rubbed the bottom of the new standoffs. This will allow JB Weld to get a good bond.6G5V6959_tuI decided to use one of the exiting mounts (The rear right one when the top panel is on the unit and you are in front of it). This places the new fan offset over the heatsink. That way the dead spot in the fans center is not centered over the heatsink.
  4. Assemble the fan with new mounts. I ended up using a washer under the screw head and another between the fan and standoff.6G5V6955_tuNo need to crank things down here. In fact that may bend things out of square.
  5. Apply JB Weld. If you are using one original standoff you only need to apply JB Weld to the other 3. I carefully dabbed it on with a chopstick. I didn’t want to use too much since it will “weld” up the bottom threads.6G5V6965_tu
  6. Once it’s in place make sure it’s level and doesn’t rock. Now allow to cure overnight.6G5V6968_tu
  7. When you put the top panel back on you may want to insure the fan power wire is out of the way and not resting on any potentially hot things.

Here are a few notes on things to watch out for.

If you use a lot of washers you might not clear the heatsink. Try to insure the new mounts are square as possible. To make up for any variance you can try rubber washers.

Congratulations. You just spent 80% of you time on .02% of the problem.

 

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