Thermally controlled fans have been around for many, many years, but
are finally now finding homes in many PC's. The basics behind these
fans are quite simple.
The fan comes equipped with a small heat-detection unit, which can
control the RPM speed of the fan. Once the temperature rises beyond
a certain threshold, the fan will receive more power and spin faster,
thus, cooling down the area that was once too hot.
These fans are great for us noise conscious, because most will spin
down to inaudible levels when not being used. They may not be the
best performing fans on the market, but next to no fans, thermal sensing
fans are a great solution for silent PC's. Thermally controlled fans
are usually a few bucks more than non thermal sensing fans.
As an offshoot of thermally controlled fans, a very small amount of
companies have actually shipped products with user-controlled fans.
Most of these fans come with a small switch on the fan, which allow
you to tweak the fans voltage, allowing it to spin up or spin down
at different speeds, depending on how much cooling performance / noise
BayBus / FanBus
Another method of fan control is to utilize a centralized power hub,
which all fans connect through. The centralized hub can be controlled
by the user via toggle switches on the front of their case, and allows
the user to turn on / off fans whenever they feel like it. Cliff Anderson,
who came up with the original ideas for the FanBus, originally came
up with this idea.
Getting a Fanbus unit is great, as it allows you to switch off all
your non-essential fans when you're doing basic work like web browsing
When you fire up a game though, you can flip all your fans back into
action with a flick of the wrist, and keep your rig cool when playing
system intensive games. Many stores have kits you can buy to make
your own Fanbus / BayBus unit, but it does require some manual labor.
Also worth mentioning, MacPower's Digital Doc 5 can accomplish these
same functions, but requires no labor. The units are expensive though,
at around $60.