Computer Fans, Heat Sinks & Cooling

Computer Fans, Heat Sinks and Cooling Systems

Heat management is essential for keeping your computer running. There are many different types of computer cooling systems available, and different users will benefit most from different types.


Like all electronics, computers generate heat when they are used. Excessive heat can cause unstable performance or even permanent damage. This problem is of particular concern for overclockers, who increase the maximum speed of a CPU or GPU for extra performance at the expense of extra heat.

Heat Sinks

GPU and CPU heat sinks are essential for proper computer operation. They provide passive cooling for the working components of the computer, absorbing heat from them and then dispersing it into the air. They are typically made from aluminium alloys, but can also be made from copper or contain both copper and aluminium components. Heat sinks work best when they have a firm connection to the CPU or GPU, and so springs and clips are used to hold them in place. Thermal paste is smeared on the contact surfaces between the heat sink and the CPU or GPU to fill in any microscopic imperfections in the surface.


Typically, computers feature both active and passive cooling systems. The most common active cooling system is the fan. A typical desktop setup will have at least two computer case fans, as well as dedicated fans used to cool the CPU and power supply unit. Case fans are used to draw cool air into the system and across the hot components and then eject it. Usually, intake fans are placed close to the ground at the front of the case and exhaust fans are mounted high on the body at the rear or on the top. Depending on the purpose of the computer, builders may aim for positive pressure (more inward than outward air flow) or negative pressure (more outward than inward). Negative pressure will cool hot components more effectively, while positive pressure helps to keep dust out of the system.

Water Cooling

For some applications, CPU heat sinks and fans are not sufficient to keep the system cool. Some heavily-overclocked desktops rely on water cooling instead. Water cooled systems use pumps to force cold water through pipes inside the case. The water absorbs heat from the components and then dissipates it as it passes through a radiator positioned outside the case. Water absorbs heat more effectively than air, and getting rid of the high-RPM fans also makes your computer run a lot more quietly.