Hello Hannes22,
A few notes on the topic of a fanless computer and acoustic noise.
I never built a fanless computer, but this idea remains with me very attractive. The advantage of a fanless computer is that the operation of the machine becomes very quiet, and that in turn is good for my wellbeing.
+ I hope one day that all PCs are fanless. Today that is not happening. That is because people prioritise computational power over acoustic noise, and to fit their budget, then go for quietness as an after thought. Yet, with todays technology a fanless computer build is still possible.
- The drawback of a fanless PC is that there is compromise in either the cost of the build, or the computational power of the CPU and GPU, or even the size of the components would be compromised.
How many fans normally are present in a modern PC?
In a modern PC, there can be fans on the front, rear and top of the case, over the CPU, over he GPU, over the Memory sticks, behind the HDD cage, and inside the Power Supply. Fans in the PSU, and on the CPU are the two most normal fans to have included on any computer build.
Are all these fans necessarily a bad thing, acoustically speaking?
No, fans can dampen or disguise other sounds such as hide the sounds produced by the CD/HDD, or hide the sounds of you typing at the keyboard.
Is getting rid of fans the only way to reduce the acoustic noise produced by my computer?
No, you can reduce acoustic noise by gettting a bigger case. A bigger case has the advantage that it is easier to get more air to circulate around the hot components, therefore the fans can run slower. Also, a better quality case is generally designed to be noise dampened. ALSO if you use BIGGER fans on the case then they can push more air and therefore operate at a slower speed. BIGGER fans are therefore quieter than smaller fans. Also QUALITY fans are quieter than "stock coolers". A stock cooler generally produces approximately 30 dB of noise, at full speed. Whereas a quality fan can produce less than << 18 dB (ie virtually inaudiable). So in part, the problem is that manufacturers are pushed to provide cheap coolers to keep the costs down, whereas, in actual fact, we want better quality coolers, therefore quieter fans. And, while better quality means more cost, using quality coolers could turn out cheaper than a totally fanless computer.
The second option, is to build a water cooled computer. Whereas a fan cooled PC pushes air around tpo keep things cooled, a water cooled PC uses water to absorb and displace the heat. Some fans are necessary to keep the water tank cool, but these can be slower and therefore quieter than fans fitted directly on the heat sinks of hot components.
What is the easiest option to reduce acoustic noise?
Buy a headphone / headset that you can plug into the computers audio out connector. You then listen to music constantly at 50 dB, to drown out distraction noises. Disadvantage is that while headphones block unwanted noise they can also block useful sounds such as doorbell, or phone ringing.
What is next on the list of noise reduction?
A HDD (hard disk drive) uses moving parts. These parts are somewhat noisy. The alternative is to use a disk drive with no moving parts, such as a solid state disk (SSD). Therefore replacing a HDD with a SSD is a step towards making the PC quieter.
How do I actually make the computer fanless?
(1) Use a fanless power supply. Such power supplies can be bought separately, or as part of a Multi-media or SFF (Small form-factor) case. It is also worth noting that some high-end PSUs have fans on, but they are not used until the PSU reaches a certain temperature. Worth reading the small print of anything that you are considering purchasing. (2) Use a fanless heat sink CPU cooler. Problem is that they do not actually disapate much heat, therefore opt for water cooled PC, or a HSF (Heat Sink Fan) that has larger, better quality moving parts. Some HSF also allow two fans to be attached. This can be quieter in that each fan need do only less work to move same heat. (3) Attend to the choice of GPU. Some GPUs are fitted on the CPU die, therefore the need for additional fan cooling for the GPU has been eliminated. Otherwise fanless GPU/VGA coolers have been available in the recent past. Again the problem is that they do not disapate much heat, therefore compromises the size of GPU compute power available in the build. Otherwise opt for water cooling. Some more modern GPUs, while they have fans fitted, do not actually turn on until the temperature onboard reach 60C, or so. This is another point worth bearing in mind, when considering your options.
Summary
- Different options result in different levels of noise reduction. Not all noise is produced by the computer fans.
- A totally fanless computer would have a fanless PSU and a fanless CPU HSF. The GPU may also be fanlessly cooled, or it might be integrated with the CPU.
