The cooling system is new too, being used in the XPC SB81P for the first time. The Barebones' case lid is not totally enclosed, but rather has a number of small, square ventilation slits in the side panels towards the front through which air is sucked into the case. The air is then blown through a plastic duct through the heatpipe and cooling ribs of the CPU fan. Finally, another fan rapidly ejects the heated air on the opposite side.
The principle is simple, but ingenious. Our measurements showed that the air outflow reaches a temperature of 51°C. Two plastic air ducts and two fans make sure that as little heat as possible makes it into the interior of the Barebones.
If you think that these fans make a great deal of noise, you are mistaken. Even after several hours under full load our gauge indicated only 41 dB(A).
It's got to come through this hollow passage, the air does