Every computer, from a home theater PC to the most gargantuan gaming rig generates heat during operation. This heat must be removed from the hardware within, or your rig could experience serious damage.
Air cooling uses fans and a big metal heat sink to cool the CPU and other hardware. Liquid cooling is more efficient and quieter, but may pose a higher risk of electrical damage.
Heat Pipes
Unlike fans, heat pipes have no moving parts and are quiet, maintenance-free, and highly dependable. They operate on a closed two-phase cycle and are ideal for applications where space is limited.
As the liquid in a heat pipe cools it vaporizes, increasing the vapor pressure at one end of the pipe. This vapor then moves to the lower pressure condenser side of the heat pipe, where it is cooled by fins. The wick structure is porous to allow the vapor to be drawn back into the liquid by capillary action, much like the way water soaks into paper towels.
Heat pipes can be designed to operate over a wide temperature range depending on the working fluid, the wall material, and the wick materials used. They are often used in electronics cooling because they can be operated at temperatures below freezing. The working fluid must be compatible with the wall and wick materials, or a chemical reaction may occur.
Heatsinks
Heatsinks are metal devices designed to absorb and disperse heat from hot components such as CPUs, graphics processing chips and RAM. They typically have a base-plate of copper, aluminum or another metal with fins that spread out across it to increase surface area for better heat transfer and cooling.
They are usually attached to a processor with thermal interface material, which is often a lubricant like grease or a liquid metal such as aluminum or copper. These materials are better at transferring heat than solids and have high thermal conductivity, allowing them to absorb and disperse more energy.
Ideally, heatsinks are used in conjunction with fans that move air over them to aid cooling. Dust buildup on the fins of a heat sink may reduce efficiency, but can be countered with a gas duster. Also, the type of thermal compound used in a heat sink may also be important, since it should be only as thick as needed to effectively cover the component and heatsink.
Fans
Fans are used to cool many parts of a computer, including the case, CPU and GPU. The most common application of a fan is on a video card, which helps to keep more powerful graphics cards from overheating when running 3D games and video editing applications. Computer fans are also found on hard disks and power supplies to help them cool.
The ideal configuration of a PC’s fans is to have positive pressure in the case, which means that more air is pulled into the case than is exhausted, so that dust doesn’t build up inside. This can be achieved by orienting all of the case fans so that they blow air outward, or by using a front and rear fan combination to allow cooler air to enter through passive openings and blow hot air out through exhaust fans.
Fans come in a range of sizes and thicknesses. Thick fans are designed for low-clearance cases, while thinner fans are more compatible with standard desktop case designs. Lighting is a popular option for computer fans, with both single-color and RGB LED options available.
Liquid Cooling
Liquid cooling distributes heat more evenly than air. It’s a good choice for high-end PC builds and high-performance overclocking.
A waterblock connects to the CPU and is filled with liquid coolant, which transfers the heat from the metal contacts to the fluid. The coolant moves upward through tubes to a radiator. Then fans attached to the radiator move the fluid through the case, cooling the rest of the components as it goes.
Most liquid cooling systems use distilled water with the addition of a corrosion inhibitor and biocide. These additives remove the minerals that can harm your CPU’s cooling system over time and help prevent bacterial growth.
Some liquid coolers may also contain a glycol variant, which improves the coolant’s heat capacity and protects against freezing. Other PC cooling solutions use dialectic fluid, a non-conductive liquid that is slightly less corrosive than deionized water. Typically, these liquid cooling systems are sealed and pre-filled for easier installation.