Energy efficient cooling of notebook computers

The majority of today's leading-edge notebook computers relies on heat pipes for internal spreading and use forced convection, with micro-fans, to reject heat to the ambient. Such techniques have worked efficiently in the relatively flat form factor of these computers, but may not be capable of providing high heat flux cooling in ever shrinking volumes. Moreover, the power limitations of portable computers, as well as growing concern for the environment, make it desirable that the requisite thermal management be accomplished with a minimum expenditure of energy. It is, thus, essential that the developers of such notebook computers follow a rigorous design methodology and achieve an optimal design for energy and space savings. This paper illustrates a "top down" thermal design methodology aimed at achieving energy efficient thermal management in a compact notebook computer, while satisfying the requirements for highly integrated design. The paper begins with a review of the passive cooling limits, and uses analytic models to determine the thermal performance that can be attained in a standard notebook form factor. Numerical modeling, along with additional analysis, is used to design the optimum compact active cooling system for both for space and energy efficiency.