How to build a completely silent fan for your cabinet

Update:
I needed to change the mounting I have described in this article. More on that here:
The Silence of the fans

Original article:
I understood early that I needed some active ventilation if I wanted to have my HTPC inside a cabinet. Of course this ventilation needs to be silent.

You can read about the cabinet here:
Building a cabinet for the living room to house a HTPC

This is the solution:
A 120 mm fan running at 220 V, speed adjusted with a special device for… well… adjusting fan speed…

I tried mounting the fan directly on the cabinet. No matter how slow I ran the fan it would make a very clear noise. So, I had some kind of idea of how I could mount the fan using rubberbands. I have silenced all my hard drives using floating systems like this.

Last weekend I had my parents visiting, and my father was helping me finishing the cabinets. I told him about my idea for the fan. Half an hour later he had made the following arrangement:

The fan is completely silent, it pushes huge amounts of air, and I have never had a lower CPU temperature than what I am experiencing with my computer inside this cabinet.

Here is a video clip showing the functionallity:
Link to video with silent fan – Windows Media

Edit: Here are some more pictures of the attachment of the fan (click them to enlarge):

How to build a completely silent fan for your cabinet

14 thoughts on “How to build a completely silent fan for your cabinet

  1. Mark says:

    Hi,

    Great idea, but could you show more details of the attachment?
    Is the elastic doing all the holding or what?

    Mark

  2. I have now posted some more photos. The hole in the cabinet is slightly larger than the fan. As you can see from the video clip it “floats” on the rubber bands.

    So: yes, it is the four rubber bands that does all the holding. I was actually a bit sceptical, but it has been working fine for half a year.

    I have now added an air filter at the bottom of the cabinet. If one of the rubber bands is cut off the fan will be stopped by the filter and not fall all the way to the floor.

    I also have a plan for some kind of extra arrangement to accomodate the fan if the rubber bands give in.

    I have just put together another cabinet for the same type. It holds two computers, a scanner, a 1 GigaBit hub and some other stuff.

    Works very well that one too.

  3. Charles says:

    Thanks for posting this. You’ve helped me solve a big problem with my setup if I can implement something similar. Could you elaborate on the specs of the fan, the wiring and the “special device” that lets you control the fan speed? Could you tell me where you found the fan and controller?

  4. The fan is a 120mm fan that I bought in a Norwegian shop called Clas Ohlson. The data for the fan is as follows:

    220V, 30W/0,125A
    Amount of air: 2,40 m³/min (at full speed)
    Rate: 2800 o/min (at full speed)
    Noise: 43 dB(A) (at full speed)
    Size 120x120x38 mm
    Weight: 0,55 kg.

    The device for adjusting speed is simply called a speed ragulator. Not much technical data in the Clas Ohlson shop, it is 220V, can adjust from 0,05 to 0,5 A. Here is a picture of the device: Speed regulator

    I guess it would be no problem to mount a standard 120mm and 12V computer fan and get the power to run it from the computer inside the cabinet. By doing that you could just buy a fan regulator for your computer to adjust the speed to a resonable level.

    What I also have experienced is that the fact that the original computer cabinet that I am using inside the home built cabinet is open in the bottom. That way the fan mounted in my home made cabinet blows the air directly over the motherboard, giving very good cooling even at a low speed.

    In the new cabinet that I have built I have a computer that is a bit more tricky when it comes to airflow. I actually had to mount an extra fan in the computer to drag the fresh air from the bottom of the cabinet and on to the motherboard.

    Hope this helps… Please feel free to ask if I need to explain things better.

  5. […] I have described the cabinet here and the mounting of the fan here. To put it short the fan is mounted in rubber bands to eliminate vibrations and noise. However, I should have said “was mounted”. The problem is that rubber bands need maintenance. Of course I could try to find better quality rubber bands, but I have choosen another soultion. It works fine so far, so I decided to post a little “How-to” for the people that might want to build something similar.To fix this mess I used a perforated strip and some parts from a kit for silencing fans and hard drives: Mounting the fan using these parts you get rid of nearly all vibrations and can have a fan that push a lot of air through your cabinet. I’ll let the pictures talk for themselves and keep the comment option open for the people that have questions. […]

  6. Jericho says:

    Great article! I was curious though, do you manually turn the fan on or does the fan turn itself on automagically? I would think an auto-temp sensing fan would be cool (no pun intended..:). It would be a pain to walk my lazy butt over to the rack, after programming my universal remote to turn everything on in one go…

  7. The system is running 24/7, so I never turn it off…

    I guess it would be no problem using a fan that was powered by and connected to the computer instead of using a separate 220V fan.

    If you use a standard 12V fan powered by the computer it is easier to temperature control it and it will turn on and off with the computer.

  8. Hi,

    Nice design. I have a client which has a cabinet holdin 2 pc’s and a router. How do I work out how much air i need to move (i.e. fan size)? And..is the bottom the best place to put an extractor? I assume the above pictures is of a fan pushing the air out of the cabinet? Is there any reason why the fan is not in the top of the cabinet?

    Regards,
    Grant

  9. Sorry for the not so detailed post. The fan push air into the cabinet. You are completely right. If it was pushing air out of the cabinet I would have placed it at the top.

    There is a natural flow of air up through the cabinet because the hot air goes to the top. So I push cold air into the bottom to help that flow.

    I want it this way because this gives me control of where the air enters the cabinet. I want excess pressure in the cabinet and not any kind of underpressure.

    With overpressure in the cabinet I can add a filter to the main fan and know that most of the air entering the cabinet will be filtered. With underpressure all kinds of small gaps in the cabinet will take in air and collect dust.

    As for the amount of air. I have adjusted that manually. Put both computers on 100% CPU load with temeprture readings on both of them. Let them run for a while and adjust the fan until the temperature stabilize just below the maximum you want in there in this extreme 2 x 100% load situation.

    Yes I know. Not very scientific…

    An alternative would be to have a temperature controlled fan in the bottom of the cabinet.

  10. Barry says:

    tbh, i use something like this to keep my xbox 360 cool, works a charm, i;m not to fussed about the noise that comes out because the xbox fans are loud anyway, so now the cabinit is child locked to stop little kid from playing with it and the xbox is kepted cool, pc fans do wonders:D

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s