Questions about water cooling.

[Futures Truth]

Can you only water cool you Graphics Card, and hard drive?

Also, I've seen cases, where they have it water cooled, but also have a fan on a certain part, [not too sure as to what it is]. If the case is sealed, what purpose does the fan serve, or are there actually holes in the cases to let the air out?

[j.woody]

You can basically watercool any component, Ram, cpu, chipsets, even a power supply!!!

the case is never sealed, the thing that the fan is cooling is a radiator that dissipates the heat. and there is always a radiator in a watercooled system.

[PeterStoba]

As said, you can cool just about everything. Wether or not it benefits you is a different thing all together.

CPU and GPU, sometimes the motherboard (depending on the chipset) are the only things worth cooling really.

The case isn't sealed, the radiator has fans attached that draw air through it and out of the case (if it's internal) or just draw air through it (if it's external).

There are still fans to provide airflow for things like the motherboard, hard drives, RAM etc...