Physical Makeup of PC Cooling Fans

PC cooling fans are normally square shaped and are available in a number of sizes. The most common sizes in demand include 120mm, 92mm, 80mm and 60mm. Round PC cooling fans are available as well. The airflow that is created by these cooling fans is measured in CFM or Cubic Feet per Minute. RPM or Revolutions per Minute is the magnitude which measures the speed of the fan’s rotation. Most users tend to choose fans with a CFM rating which is on the higher side.

A majority of PC cooling fans allow users to adjust the RPM so that they are able to modify the amount of noise that is produced.

Different fans use different bearings. This selection largely affects the amount of noise that is produced as well as the performance of the fan.

The different types of bearings used include:

1. Sleeve Bearing: Those fans with sleeve bearings consist of two surfaces which are covered in grease or oil. This lubricates the machine and makes friction possible. Fans with sleeve bearings are not considered to be ideal because the lubricant tends to get dry rather quickly which causes the system to fail. If these bearings are kept at a high temperature, it is more likely that the system will break down. They must always be mounted in a manner which keeps them vertical at all times. Even though such PC cooling fans are silent when they are new, they tend to get extremely noisy over the years.

2. Rifle Bearing: Those fans with rifle bearings are quieter and have a long life span when compared to those fans with sleeve bearings. These bearings consist of grooves that are spiral in shape. A reservoir pushes fluid into the groove. Rifle bearing fans can be kept horizontally or vertically.

Other bearings include ball bearings, fluid bearings and magnetic bearings.

Another important component of a PC cooling fan is a fan connector.

These come in different varieties:
The first kind connects the motherboard and the fan. It is rectangular in shape and is quite wide. This small in-line connector has two tabs which are located towards the edge of the component. The pin sockets are spaced far apart and are adequately sized. An example the 3-pin Molex connector.

The second kind is one which connects the PC cooling fan and the power supply. The connector offers a red and black wire which connects to the power supply and makes sure that the electric current is continuous and constant. An example is the 4-pin Molex connector.

The third kind uses the characteristics of the above mentioned connectors and consists of two tabs at the centre and another tab which is located towards the side. The spacing and the size is similar to the 3-pin and the 4-pin. A white wire may also be present which adds to the current and makes the fan move faster.

An example is the Dell Inc. proprietary.