Overview of notebook fan noise reduction efforts.

Notebook computers face particular challenges with regard to cooling the interior components and the surface of the chassis that is in contact with users, in addition to being operated in a wide range of thermal and acoustic ambient conditions. Fan airflow is responsible for about 85% of the cooling capability in typical designs, and is in turn limited by acoustic considerations. This paper will review fan‐level and system‐level efforts by Intel Corporation to promote low noise fan and system designs. Test fixturing to emulate the restricted space inside a notebook computer, combined with an ISO 10302 plenum, can be used to generate constant sound power fan curves, which capture multiple aspects of fan performance. It can be shown that the optimum design is different for the installed condition than for the free space condition where noise is typically reported today. At the system level, the chassis impedance is intimately connected to the airflow at a chosen noise limit. The location of the fan exhaust ...