FrostyTech has reviewed Zalman's CNPS5700D-Cu Ducted P4 Heatsink :
When the Zalman CNPS5700D-Cu arrived I have to admit there was a bit of a "whoa" factor to contend with. The heatsink and air duct are not like anything we have seen on the cooling market before, so it was a treat to see first hand. The clear blue air duct also posed some interesting questions about case cooling efficiency.
The basic idea behind the Zalman CNPS5700D-cu is a simple one. The fan is oriented upside down so air is drawn up though the base of the heatsink, up through the copper fins and then into the fan which exhausts the now warm air out via a custom plastic air duct.