A thermal design approach for natural air cooled electronic equipment casings

In recent years, the increasing demand of compactness and high-speed performance of electronic equipment had led to an increasing trend of power dissipation density. Therefore, suitable cooling techniques to the thermal designing of electronic equipment need to be developed. Several research reports on electronic equipment cooling are available in the literature sources [1-5]. In these studies it can be observed that air-cooling is getting one of the important cooling techniques, since most of the electronic equipment are cooled by air convection. Although fan cooling is most widely used in the air cooling techniques, the noise generated by the fan is publicly criticized. As a result, cooling on the basis of natural convection is one of the attractive approaches. However, only limited data on natural convection, which can be used in the practical design of electronic equipment, are available. Noronha [6] studied the effect of the component locations in cabinets to achieve maximum natural cooling efficiency. Guglielmini et al [7] have reported on the natural air cooling of electronic cards in ventilated enclosures. Ishizuka et al. [8] proposed an approach using a simplified set of equations which represent the cooling capability through a natural air-cooled electronic equipment casings. However, detailed discussions on derivation of the set of equations were not made in that paper. Therefore, in the present work, an attempt has been made to study the effects of the outlet vent area and power dissipation unit location on the natural air-cooled electronic equipment casings.