Fans would still be required to effectively exhaust heat from inside the chassis. Liquid cooling simply allows for a more efficient rate of heat exchange from the device(s) to the final heatsink/radiator. From there, the greater density of heat coupled with the same rate of airflow (from fans) will produce a higher dissipation rate to better cool the device on a whole. So the things to consider (in a majority of situations) for power efficiency of such as system would be the power usage of the liquid pump vs any potential decrease in fan voltage to weigh it against all air systems.
Slashdot Mirror
Fans would still be required to effectively exhaust heat from inside the chassis. Liquid cooling simply allows for a more efficient rate of heat exchange from the device(s) to the final heatsink/radiator. From there, the greater density of heat coupled with the same rate of airflow (from fans) will produce a higher dissipation rate to better cool the device on a whole. So the things to consider (in a majority of situations) for power efficiency of such as system would be the power usage of the liquid pump vs any potential decrease in fan voltage to weigh it against all air systems.