Abstract: A heat dissipation apparatus has an enclosure, in which a lateral fan seat is integrally formed with the enclosure. The lateral fan seat divides the interior space of the enclosure into an upper chamber and a lower chamber. An axis is installed across the upper and the lower chambers through a center of the fan seat. A coil set, a magnetic element and a plurality of blades are mounted about the axis in each of the upper and lower chambers. Thereby, two sets of fans are formed in a single enclosure to increase the heat dissipation effect while the assembly convenience is improved.