As we all know, computers are an important part of everyday life in the modern world, and like every other part of our lives we should be taking care to keep them in top performance condition. The important parts of a computer reside in the tower, but as they are in constant use they increase in temperature as they are used for longer periods of time and for more difficult tasks. The safe temperature range for computers is generally between 30 and 55 degrees Celsius.

The hot components, being in constant contact with the air inside the case generates a build up of hot air inside the case. This heat destroys the computer and so many different methods are used to expel this hot air, or to reduce the heat of the computers components.

The most basic method to keep the air inside the case cool is to install air vents. These vents are just holes in the side of the case which allow for fresh air to flow through the case as hot air rises, creating suction with which to draw fresh air in through the air vents. In addition to air vents entire sections of the case may be removed.

The main reason extreme air vents are not commonly used is as by creating more entrances for the air more entrances for dust are also created. Dust is not only a thermal insulator, which limits the effectiveness of the cooling airflow, but also affects the performance levels of the actual hardware in the computer.

A heat sink attached below the CPU increases the surface area of the CPU and so decreases the total energy and therefore heat over the area, keeping it cool. Heat sinks are made of a material such as copper or titanium that has a high thermal conductivity. This means it is able to conduct heat away from another material with greater ease than air. Due to the relatively low thermal conductivity of air it is important to ensure that no air is trapped in the glue between the CPU and the heat sink.

Air vents as a way to cool computer towers is not enough for many computers. Without at least one fan modern day computers can easily overheat and initiate an emergency shut down within a few minutes of being used.

To increase the effectiveness of the air vents all computers are sold with at least two fans. One is placed above the CPU and another over the power supply. Graphics cards, another important component in many computers, are sold with fans. Careful placement of the fans inside the tower allows for fresh air to be drawn into the case from the front and the hot air to be dispelled from the back of it. Poor placement of fans, as well as friction within the fans can create issues with the effectiveness of the fans by reducing the amount of fresh air flowing through the case. Fans also create noise, and noise is bad.

Water cooling is another method of computer cooling that many people utilize. Water cooling is quieter and cools with much more effectiveness but it requires occasional maintenance. When water is used only distilled water should be used. Other sorts, such as normal tap water, de-ionized water and the like corrode either the blocks used to mount the cooling system of the computers' components themselves, and we wouldn't want that.

Water cooling is much more advantageous than air cooling due to the amount of energy water needs in order to gain one degree Celsius. This value is referred to as the specific heat capacity of a material, and is found through with the equation Q = mcΔT, in which Q is the energy required, m is the mass of the substance, c is the specific heat capacity and ΔT is the change in temperature. From this equation it can be seen at the specific heat capacity or water is 4184 Jkg-1C-1 compared to air, which is approximately 1003 Jkg-1C-1. Therefore it can be observed that water is much more able than air to keep a computer's components cool.

There are of, course, other ways to cool a computer. Other liquids can be used other than distilled water. Liquid nitrogen is an interesting example, but is and should really only ever be used in extreme situations, such as competitions. Oils can also be used, and I'm sure that with a little imagination you could think of much much more!

Reference:

1. Computer Bob, 2003, viewed 30.10.2008
2. Melchiore, D, 2005, Xoxide Resource Center, viewed 30.10.2008
3. Wikipedia, viewed 30.10.2008
4. Wikipedia, viewed 30.10.2008
5. Wikipedia, viewed 30.10.2008
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