An actively externally cooled housing with at least one electronic component having heat-dissipating capacity, has a ventilation inlet located outside the housing, the ventilation inlet generating an airflow that is guided through a lateral flow channel, the flow channel being located on any side wall of the cooled housing on which at least one electronic component with heat-dissipating capacity is located, wherein the ventilation inlet is located in a ventilation housing that is located on the top side of the active-cooled housing and has a lateral air outlet that leads into the lateral flow channel, whereby an air intake occurs through only one air inlet opening that is located on the underside of the ventilation housing and which is essentially open vertically downward, so that the ventilation unit is located in the ventilation housing in such a manner that it is protected against impurities in the ambient air