Desktop computer fans play a crucial role in maintaining the proper functioning of a desktop computer. They are designed to dissipate the heat generated by various components, such as the CPU, GPU, and power supply, to prevent overheating and ensure stable performance.

One of the primary functions of desktop computer fans is to cool the CPU. The CPU is the brain of the computer and generates a significant amount of heat during operation. A dedicated CPU fan, usually mounted on top of the CPU heatsink, blows air over the heatsink to transfer the heat away from the CPU. This helps to keep the CPU temperature within a safe range, preventing thermal throttling, which can reduce the CPU's performance.

In addition to the CPU fan, desktop computers also often have case fans. Case fans are installed on the front, rear, or sides of the computer case to create a flow of air through the case. This helps to remove hot air from the case and bring in cooler air from the outside. For example, a front mounted intake fan can draw in fresh air, while a rear mounted exhaust fan can expel the hot air that has accumulated inside the case. This overall airflow management helps to keep all the components in the case cool.

Desktop computer fans come in various sizes and designs. The most common sizes are 80mm, 120mm, and 140mm, with larger fans generally being able to move more air at lower noise levels. Some fans also feature advanced technologies, such as PWM (Pulse Width Modulation) control, which allows the fan speed to be adjusted based on the temperature of the component it is cooling.

However, desktop computer fans can also be a source of noise. As the fan speed increases to cool the components more effectively, the noise level can also rise. This can be a nuisance for users, especially in quiet environments. To address this issue, manufacturers are constantly developing quieter fan designs, such as fans with larger blades, better bearings, and more efficient motor designs.