Overheating Kills: Computer Hardware Susceptible to High Temperatures

Whether it's the dog days of summer or a cold day in winter, your PC can overheat. A cool room doesn't always make for a cool PC because the parts which get hot are contained within a metal casing and individual components can get very hot.

Add to this the fact that many of us pack our PCs with more hardware than ever before (scanner cards, modems, extra drives, special adapters), reducing room in the case for air to move. We also tend to buy more of the super-fast, hotter running hard drives can trap heat if not thoughtfully installed.

The rule of thumb to remember is that the more computing power your PC has, the more heat it will generate.

What you need to know is that hot components can fail and ultimately wear out much faster than components cooled to reasonable temperatures. To keep your system running well, you have to watch the temperature.

Since our PC cases usually feel warm to the touch anyway, not everyone will know when their PC's innards are running too hot. Add to this - background noise may keep you from noticing a fan not running or components starting to groan with heat distress.

Too often, the first indication you are having a problem occurs when hardware begins to fail under the stress, and you develop intermittent keyboard or drive access/ write errors, for example, which resolve after you shut down the PC for a bit (effectively letting the unit cool down).

However, you can begin to encounter real and permanent failures the longer you run an overheating unit. Plus, a PC should never be allowed to operate for more than a very short period without a working fan or you may end up with a virtual meltdown.

Special and even mundane circumstances may conspire to make a PC overheat. For instance, overheating is a frequent result of serious over- clocking of a system.

Adding a hot new drive to a borderline, packed PC can also drive the temperature into the red without extra precautions taken. But even a lot of office cleaning - where a good deal of dust may be raised and then sucked into the PC through its front vents to be carried out by the fan in the back - may lead to a heat-insulating layer of dust on internal components or clog the fan itself, reducing or eliminating its efficiency.

To understand PC cooling, let's take a quick review of basic principles of thermodynamics, which tells us there are three major ways to cool anything: convection, conduction, and radiation.
- Convection is the transmission of heat into surrounding or moving matter, such as air or water. An example of this is a muffin fan blowing air across a hot CPU chip to reduce surface heat.
- Conduction is the transmission of heat by direct contact between a heat source and something which will draw the heat away, also known as a heat exchanger, commonly called the heat sink. One prime example of this is how your CPU and heat sink work together.
- Radiation simply takes the heat and pushes it out into the "empty space" of whatever medium is ready to receive it, like the air in your PC.

Put simplistically, your CPU or other chips generate heat in the process of working. This heat is transferred by means of conduction to the heat sink which then radiates the heat out into the air within your PC case which the fan then draws out through the back of the unit (the hot air you feel).

A working fan is quite central to keeping your PC cool, as you can imagine. Check to be sure your PC fans - and yes, you can have several, both vented to the outside as well as inside the case - are not blocked or have stopped functioning.
Did you know that PC case design can play a big role in PC cooling? A desktop case, for example, can be more prone to overheating because while air usually moves easily past the cards installed, heat can concentrate around packed drive units. The tower design offers a more ideal convection situation, since heat rises and less heat-fussy hardware tends to be located at the top of a desktop unit (CD and floppy). A larger tower should provide more air flow through the case than a mini or mid-range tower.

One thing you want to check whenever your PC cover is off is the positioning of the cables. Bunched-up cables "stuck" in the wrong place can impede air flow, and drive up the internal temperature of your PC. Errant cables and connectors can also get caught in a fan blade, which is never good. So keep them organized, neat, and out of the way. Just taking this step could add life to some of your more delicate electronic components.

Getting back to cases, some opt to leave their PC case covers off, particularly in hot summer months, to help increase heat dissipation into the room air. How good a practice this is depends on whom you talk to about this. Many seasoned PC veterans advocate this, especially when working in a relatively very clean office environment, while others insist the PC was designed to run with the cover on for maximum efficiency.

Leaving the cover off will definitely move cooler air past hot components, but you may find that your cards and other equipment build up an accumulation of dust and debris much faster than if you leave the case intact. Don't run your system with the cover off for a prolonged period of time.