Oil and gas are fuels which need little manual operation and have therefore been preferred for heating systems. As a consequence, coal-fuelled heating systems have not been developed any further. This, however has now begun to change, as high-tech is being applied to the use of coal. This development has not gone unnoticed by the German GPO. The authors give an interesting description of an almost forgotten way of space heating by describing the anthracite-fuelled heating system implemented in the post office building in Hagen (plant, feeding system, pipe conveyor, ash-removal, stored-program control). (orig.).