Abstract: A ventilation system for cooling the accessory board area of a personal computer is disclosed. The system incorporates two thin fans capable of producing an airflow of 25 cubic feet per minute. The entire system is small enough to mount between the chassis of the computer and the outer cover, thereby avoiding disfigurement of the external appearance of the machine. A lower plenum attached to the housing of the system helps direct air toward the lower portion of the accessory boards. The fans are powered by a direct current voltage, and a grounding clip on the unit automatically attaches to the chassis, requiring only one connection to the disk drive connector. An electroluminescent lamp is employed to indicate operation of the system.