How to make a computer quiet
Below are recommendations to help make your computer quieter and a listing of the main causes of computer noise.
Computer fans (case fans and CPU fans)
Most computer noise comes from the computer fans. As computers continue to get faster they continue to get hotter, which requires more fans and faster fans to help keep everything cool. A fan generates noise by spinning and moving air.
One way to reduce the noise produced by your computer is to replace the pre-installed case and CPU (Central Processing Unit) fans with higher-quality, quieter versions. The amount of noise a fan emits is measured in dBA, which are logarithmic in nature. For example, a fan with 21.8 dBA is going to be much louder than a 19.0 or 12.0 dBA.
If the computer has the available space, installing a bigger fan moves more air with slower speeds making the noise level lower. Some fans change the speed based on heat, which means if the computer is not hot, the fan speed is lower and quieter.
Power supply
A computer's power supply includes a fan and is usually another major cause of noise in your computer. If your power supply has a power switch, disconnect it from the motherboard and turn it on by itself to determine its noise level.
Otherwise, consider purchasing a new power supply with a low dBA. There are even fanless desktop power supplies available with a dBA of 0.
Hard drive
Some computer hard drives can be real loud, you can identify a noisy hard drive by listening to the noise level as information is accessed off the hard drive. For example, if the computer is noisy as it boots up this is a good indication of a noisy hard drive.
Some hard drives can also be consistently noisy, causing a steady noise while the computer has power. You can identify the hard drive's noise volume by temporarily disconnecting the hard drive and turning on the computer.
To lower the noise volume of a hard drive without replacing it, enclose the hard drive in a case can make it quieter. However, realize that many hard drive enclosures also have fans that increase the noise of the computer. Alternatively, you could replace the old hard drive with a new one.
An SSD (Solid-State Drive) generates no noise and is faster than a traditional hard drive.
Video cards
With the increased power of video cards, many of the new video cards have fans that also increase the overall noise of a computer. Unfortunately, there is no easy solution in making your video card quieter. However, for users who want to get their computer as quiet as possible, there's several online documents that have steps that replacing a video cards fan.
Other recommendations
You can also make the computer quieter by following any or all the below recommendations.
Move the computer - The location of a computer can make a difference. For example, if you have the computer on the top of your desk, try moving it below the desk.
Loose screws - Loose screws especially on fans can cause increased noise while the computer is running. Make sure all screws inside the computer are tight by going inside the computer and checking each of the screws.
Padded feet - If the computer is on a hard surface, such as a desk or hard floor, the vibration of the computer can cause additional noise. Adding padded feet to the bottom of a computer may slightly reduce the noise volume. Another tip would be to place a piece of carpet under the computer.
Gaskets - Silicone case fan gaskets are another relatively cheap solution for making your computer quieter. The gaskets install in-between your case and the fan and help reduce the vibration, making the computer quieter. Antec and other companies sell these.
If this is a home computer or a computer you need access to, placing the computer into an enclosed case can also reduce the noise volume. However, when doing this you must consider heat-related issues. The computer should have at least two inches in the front, back, and both sides to bring air from the outside.
Insulation - For users who want to make their computer even quieter install acoustic insulation, which makes it quieter but at the same time could increase the heat of the computer.
Water cooled - If you plan on overclocking and need your computer as cool as possible, and low noise levels are a priority, consider a liquid cooling solution.