Airflow
Airflow is possibly
the most important job of a good case. Components
can
get very hot, and good airflow is
needed
to get that heat away from the
components.
Without sufficient cooling, they can become
less
reliable over
time
and degrade faster.
Many cases that you buy yourself may come with only one
or two fans but have mounting holes
for more, allowing you to add extra ones. The most common fan size
is
140mm, followed closely by
120mm. 80mm fans are
also relatively common, but usually on smaller computers. Finally, you can also get 92mm, 60mm and 40mm fans, but these
aren‟t used as often.
There are three main airflow models, each having its
advantages and disadvantages:
1. Negative Pressure – when exhaust exceeds intake. The idea behind this
is that a negative
pressure gradient is
formed, sucking all the
hot
air out of the case.
2. Equalised Airflow – when you have equal air
intake
and exhaust. This
is the
most common, and works by creating a
wind tunnel.
3. Positive Pressure – when, you guessed it, intake
exceeds exhaust. The idea behind this
is that new air is constantly fed in, pushing hot air out of the
case
and replacing it with cool air.
The biggest problem
with getting a
good airflow is the
amount of noise
generated by the
fans, particularly by many small fans. There are
usually two solutions
to reducing noise:
1.
Isolate the
fans from the case to prevent noise-creating vibrations to be
passed
to the
main chassis. This does
not
make the fan itself quieter, but can significantly reduce overall noise. Many higher end
cases provide
rubber grommets
for the fans in their cases
for this purpose.
2. Buy
better fans – These tend to use ball bearings or
fluid bearings rather
than the cheaper
sleeve bearings. They have
the extra bonus of lasting a lot longer, too.
The other alternative is
to buy a case with one or
more larger fans. These are
great
because they can generate the
same CFM (cubic feet
per minute of air, the
standard measurement for
air
throughput for fans) while spinning with fewer
RPM
(revolutions
per minute) and thus
creating less
noise.
When you go to buy fans, it‟s much better to get the fans from a well-known brand.
You‟ll pay a bit of a premium, but it‟s worth it for the lower
noise and longer fan life. Some good brands to
look out for are
Akasa, Antec, Noctua, Scythe, and
Zalman. There are
some other good brands
out there, but these are the ones to get.
If you want to keep your computer as cool as possible, there
are a few companies who
will be
happy to sell you cases
designed for
airflow. Examples
include Cooler
Master’s HAF line (HAF stands for high air
flow, funnily enough) or Antec’s
Gaming Series (including
the 300, 902
and 1200 cases).
