Getting rid of excessive heat using cooling - Fans and Heat sinks.
Electronic devices create heat. Computers create more than most. Why? Well a
processor is pushing electrons through extremely small (and getting smaller all
the time) 'wires'. These very small 'wires' are really only trace amounts of
copper/aluminum alloy that is embedded in silicon. Some are gold alloy, couple
this with the resistors, capacitors, and millions of transistors all on a chip
that is a little larger than a quarter of an inch square and about one sixteenth
of an inch thick. Now you apply voltage with amperage to move the electrons
around inside the processor and presto you have a heat creating device. A processor will
run at around 71 to 165 degrees Fahrenheit. A little less than a 40 watt light
bulb. The problem is getting that heat away from the processor before it has a
chance to build up and do damage to the processor.
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.
Another consideration is the space around the computer. If the computer is in
a confined space the overall temperature of the computer will rise and that make
the incoming air work all that much harder to take away the heat. Having
sufficient clearance around the computer will lower the temperature. This is
especially important in the back of the computer where the power supply exhaust
fan removes the hot air from the computer. You should have enough space behind
the computer that the air circulating in the room will take away some if not all
the heat.
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.
If you find you need to add a new fan to your computer case before you
purchase a fan check inside your case for a place to mount it. Most fans do not
come with a mounting cage, that is a case that holds the fan. Some cases have
additional mount points for extra fans, some don't. You may have to make a cage
for the new fan.
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
The space behind the computer 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.
This site contains a lot of information. As
with any publication not all information is available due to space, time, or
subject constraints.
If you have a question that you did not find the answer
on this web site you a can
ask your question here and we will endeavor to get you the most up to date
answer possible!
