Cooling by water or air?
There are two main categories of processor coolers, air coolers and water coolers. Air coolers consist of a heat sink that can be directly connected to the processors via heat pipes. Air coolers are usually equipped with one or two fans, which blow cool air through the heat sink to dissipate the heat generated by the processor. Air coolers have the advantage that they are relatively simple to set up, can cool well and usually offer good value for money. A disadvantage of air cooling is that the warm air from the processor (partially) gets stuck in the housing. Although many air coolers direct the warm air towards the back of the case blades where an outtake fan is usually present, the temperature inside the case almost always rises when the processor is loaded more heavily.
Water cooling solves the latter problem. Water coolers consist of a water block that is mounted on the processor and connected to a radiator by means of two hoses, with one or more fans on top. This radiator is mounted on the front top or back of the case, where air from the case is blown directly out through the warm radiator. Water cooling also has disadvantages. Although modern ready-made kits are of high quality, there is always a risk of leakage, in theory, with all possible consequences. However, the main disadvantage of water coolers is their price, which is in most cases significantly higher than that of normal air coolers.
Air cooling: Tower or top-flow?
In addition to the distinction between air and water cooling, we can also divide air coolers into two categories. Top-flow coolers consist of a heat sink with a fan at the top that blows air from top to bottom through the fans at the top of the heat sink. The advantage of top-flow coolers is that they are usually quite thin and can therefore also be installed in narrow chassis. Because top-flow coolers blow air down, there is also air flow over the motherboard, which - depending on the layout of the motherboard and the fins of the cooler - also cools the power supply to the motherboard.
The disadvantage of top-flow coolers is that the air is blown towards the motherboard and therefore ends up in the system. The heated air increases the temperature inside the case, so that a good air flow from the case itself is necessary to prevent it from getting too hot.
The second category are tower coolers. This type of coolers is relatively new and uses a metal base plate that is connected to one heatsink, which usually consists of dozens of wafer-thin metal fins, by several heat pipes. The base plate is mounted on the processor and transfers the heat from the CPU via the heat pipes to the slats. On the side(s) of the cooler there are usually one or two fans mounted, which blow cool air through the slats and thus ensure that the heat is dissipated. The advantage of tower coolers is twofold. First, they usually offer a much larger surface area where heat is transferred from metal to air, which makes cooling much more efficient. Tower coolers with heat pipes and metal fins usually cool much better than top-flow coolers that consist of a solid aluminium cooling block that is built with cut or cast fins.
In addition, the air flow of top-flow coolers is much more efficient. PC enclosures are designed so that air flows from front to back through them, and virtually all modern PC enclosures have one fan at the back that sucks warm air out of the case and discharges it outside. Tower coolers blow the air to one side, where it can therefore be absorbed into this front to back airflow of the chassis. Indeed, in practice, the processor position is usually just next to the outtake fan at the back of the enclosure. Tower coolers blow the heated air directly towards this fan, so that most of the processor heat is directly blown out of the cabinet.
Unfortunately, tower coolers also have a disadvantage. Because the fan is upright and usually 12 cm fans are used, tower coolers are usually quite tall, think 15 to 17 cm. This is usually not a problem in normal ATX housings, but if you have a micro-ATX, ITX or a low HTPC housing, a large tower cooler will not fit.