[en] The author reports on the sectional aspect 'ventilation installations' and discusses the problem of the creation and maintenance of the climatic and radiological conditions in that part of the light-water reactor (LWR) where there is radiation danger as well as with their effects on the environment, and the emission of radioactive exhaust gases during correct operation and in case of breakdown. He describes the ventilation installations and describes their function in relation to a pressure-water reactor (PWR). The regulations and recommendations are valid for the Federal Republic. (orig.)