Liquid cooling

[EdH]

I might be quite mistaken, but I believe the preferred setup is to blow the surrounding air into the heat sink.

[sdbardwick]

I arrange them to blow towards the case exhaust fan.

[Mark Rose]

Originally Posted by ThomRuley

The other question I had was how do you tell which side of the fan should face the block? Both sides seem to mount equally well to the block.

The side with the wires should face the heat block in a push configuration. If you add a second fan to increase cooling performance, orient it in the same direction so it pulls air out of the block (wires opposite to the block). Cooling blocks generate relatively high static pressure, and fans for high static pressure are generally designed to push air and not pull it.

[Xyzzy]

Your fan will have an arrow on the side indicating which way it blows air.