Computer Dust

Dealing with computer dust
One problem with computer fans is they get stuck in dust. Whether it be a little fan on a graphic card or the computer's huge power supply block fan, after a year or so they are smeared in fine dust filaments. If a heatsink is placed beneath a fan it can accumulate quite a bunch of dust. This lowers the cooling performance of the fan and even can make it become noisy. Some people do open their computer once a year and vacuum clean all that dust inside and around the fans. Other ways round can be these:

Self-cleaning fans
The obvious way to make a self-cleaning fan is to make it able to turn in both directions. By blowing the opposite way the fan will blow away at least most of the dust that accumulated. There are variants to this basic principle:

The fan can blow half the time in one direction and half the time in the other direction. I'm not sure this is the best solution because in some cases the dust will not be blown away. For example there where the air speed is quite low. I fear it may tend to make even more dust accumulate. Because the dust filaments stretched towards one direction will make other dust filaments blown the other direction adhere easily. Like a comb retains hair.

The fan can once in a while blow much stronger. This will blow a part of the dust away.A friend told me on industrial systems he installs very strong fans in order to permanently prevent the dust to adhere. This may cause problems because there will always be places the air slows down and dust does deposit. Besides a very strong air stream can cause problems on itself. A solution can be quite a little system, composed of a little yet powerful compressor that blows air at a very high speed through a little and enclosed heatsink. The air output would blow towards open space where the air would slow down without particular possibility to deposit dust. This has the advantages to be little and avoid most dust deposit. On the other hand it is more power consuming and more difficult to keep noiseless. An interesting possibility is a mixture of the above: a fan that once in a while starts blowing the opposite direction and with more force. This will detach and expell most of the dust.Blowing the other direction requires the fan blades to be flat and not curved. In order to be able to blow efficiently in both directions. This in turn requires the fan blades to be not too much inclined. Which requires the fan to run faster to get a same air flow. Or to have two propeller stages and maybe two static stages like a compressor. The fact the fan has to be able to blow a least a short time at high speed requests for a stronger motor and a little more sophisticated electronics. This ensures for a more reliable functioning at standard speed which is a good thing.

Next puzzling is what should trigger the fan to blow the opposite way. Many criteria can be proposed:

The fan can do that on a regular basis. Say every month or every one million turns. The problem is the noise generated during that process and possibly the dust cloud can be surprising and annoying.

The fans electronics' can compare the turning speed to the voltage and infer when the fan seems to be stuck in dust. This is a quite unreliable criteria to me because many things can make the fan turn slower. Anyway this could be used if linked with other factors and a rudimentary neurons network.The fan can be triggered to blow the dust away by the computer's user. Tuning addicts would be glad to have buttons in a window or on or their computer's case for this purpose. The way the fans are linked to the command buttons are a matter of questioning too. That can be a dedicated USB device, an on-board motherboard function, wires and buttons, a sound-tone code listening microphone inside each fan...

What will happen with the dust blown away? Part of it will fall to the bottom of the computer which is not a problem. Another part will be propagated to the room the computer is situated which is more problematic. It may also trigger health accidents like asthma. Opening the windows can help. A partial solution could be to synchronize the fan cleanings. First the computer's main fan situated in the power supply block should do a short and powerful cleaning. This will generate a dust cloud inside the computer case. The fan should immediately stop. Then the other fans, situated on the motherboard and cards should clean, adding their dust to the the dust cloud inside the case. Then the computer should go into low power consumption or shut down, till most of the dust did deposit on the bottom of the computer case.

Aspirate the air from the heatsink instead of blowing towards the heatsink If the ventilator blows towards the heatsink the dust will accumulate between the ventilator and the heatsink. This makes the dust quite hard to clean. A solution is to turn the ventilator 180� and make it aspirate the air from the heatsink. That way the dust will accumulate on the open sides of the heatsink and it will be much easier to clean. I wrote a Web page about this.





We servcie all Major Brands