Originally Posted by shadow001
Depends on the pump, and it being a pretty weak unit to begin with with very low pressure and flow characteristics.....Don't confuse this with heavier duty pumps that can output 2~3 gallons a minute like heavier duty pumps can and 20+ feet of head pressure, and using 20 watts of power for the motor itself when running at it's max speed.
Setups like the above picture can match the best aftermarket aircoolers but be more silent and that's it.
Head pressure only matters in an open loop. It will not matter at all in a closed loop.
Even in the manual for his cooler it states orientation of the radiator will have no effect on temperatures.