In this essay a dynamic model of a shelter was elaborated by means of a deductive model, first on an analog computer, then on a digital computer. It was computed on the basis of the given air data, the geometry, the thickness of the lining as well as the quantity of air to be exchanged, the time temperature graph, the relative humidity, the drift of heat out of the shelters through the walls as well as the time process for the difference between the quantity of heat and vapour introduced and the quantity expelled by the walls. As well the total quantity of vupour and heat accumulated in the walls during the test period was also considered. The time processes have been charted as well as illustrated. Besides it is possible to introduce into the model computation, the heat radiations debit on a flat roof of a shelter. The programme computes on the basis of quantity of heat per time-unit that the roof receives and respectively radiates, considering also the time of year and the time of day. At the same time it largely takes into account the actual ceiling's design and the materials employed.