Cooling - Fans and Heat sinks

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Getting rid of excessive heat using cooling - Fans and Heat sinks.

Add to this heat other devices in your computer case such as hard drives, CD or DVD drives, video card, sound card, all the support chips for the motherboard, memory, a network card, and maybe a modem. All these devices create heat. So you need a way to dissipate or move the heat away from the devices and outside the case.

For the Processor you will have a piece of metal that has fins or groves cut into it, these fins allow the air to pass between them absorbing the heat generated by the processor, this is called a heat sink. It absorbs the heat created by the processor and spreads it out across the fins. Add to the heat sink a fan to move the air across the fins and you have reduced the heat build up in the processor to a level that the processor can with stand for long periods of time. Be aware that the processor has an operating temperature spectrum. It's peak efficiency will be around 100 degrees Fahrenheit.

Your main consideration for heat dissipation is the air flow into and out of the computer case, also the flow inside the case. A contributing factor in a processor, memory, hard drive, or video card over heating is air flow. If the device is not getting sufficient air moving across it then heat will build up around the device, air stagnation is a device killer. Another problem with air flow is the ambient air that is coming into the computer. If it is not cool enough to absorb the heat inside the computer then it does nothing to cool the devices inside the computer case.

If your computer is shutting down after a short period of time it maybe that the processor or the motherboard is over heating. Newer motherboards have a heat protection circuit that will keep the motherboard from getting to hot. The processor how ever does not but if the processor is creating enough heat to shut down the computer then increasing the airflow over the processor and the surrounding area may stop the heat circuit form shutting down the computer.

How would you test the computer to see if it is overheating?

One way would be to go into the BIOS settings and see if there is a 'Hardware Monitor' that will give you the processor and motherboard temperatures and the maximum that the processor and motherboard can endure before the over temperature circuit shuts the system down.

Start your computer and go into the BIOS settings and note the temperature when the system has been off for over an hour, this should be sufficient time for every thing to cool off. Let it run an see how high the temperature gets to, if it shuts down while in the BIOS settings you need to increase your cooling as soon as possible.

The system may not be over heating while in BIOS due to the extremely light load on the processor and the devices. It may only over heat when under heavy load. If this is the case start in the BIOS settings note the temperature then let the system start up as normal and then put it under heavy load. When it shuts down try to restart the system and go into the BIOS settings the temperature will still be very high and you can note the temperature.

Now you know the temperature range, you need to bring the temperature down to ten or fifteen degrees Fahrenheit above the minimum setting. Five to ten would be better but if the current cooling can not keep the system cool enough you may not be able to add enough cooling to get the operating temperature that low.

So how do you get the operating temperature inside the case lower? First you need to consider the ambient (still air) temperature in the area the computer is in. If you are in a room where you know the temperature is say 75* Fahrenheit all the time then that is sufficient to absorb the heat created by the devices inside the computer. But if you are unsure you need to test the ambient temperature. To do this a house hold thermometer will work, find a spot in the room where the air is stagnant, that is if you wet your finger you will feel the evaporation all around your finger and not on one side. Place the thermometer there and leave it for about fifteen minutes. What is the temperature? Next take the thermometer and place it behind the computer, close to the power supply fan. What is the exhaust temperature?

Now you have a range of the air temperature, the intake ambient (room air) and the computer exhaust air. If the difference is less than twenty degrees the only thing you can do is lower the temperature in the room, adding more fans to the computer will only increase the noise and do nothing to cool the devices.

Increasing the cooling does not always mean adding more fans to the computer case. You can get a sufficient increase in cooling by separating the add on cards, having an empty slot between the cards helps. Having two slots open around the video card would increase the amount of air the video heat sink would get to move the heat away. Bundling the cables or using cables that are round will increase the air flow in the areas where cables are routed. If you have to use flat cables making them lay flat in relation to the motherboard vs perpendicular will increase the air flow inside the case.

If you find that tiding up the cables and increasing the space between the add on cards doesn't reduce the temperature substantially then increasing the size of the heat sink on the processor and adding a intake fan may bring the temperature down.

To recap:

• The air temperature in the area where the computer is located is a large factor.
• The air flow through the computer is a factor
• The heat sink on the processor is a factor
• The intake air is a factor

So before buying that super-duper water cooled heat sink check the above factors it may save you some money.

Note: For laptops the cooling and air flow is designed to the maximum inside the case, if the system is over heating you may want to consider a cooling pad, they are available at most electronic stores.

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