nominal thermal dissipation of the network in operation are preserved by separating the air flows corresponding to each network inside the tower for this purpose a tower with two concentric shells is produced in which the partitions delimit the independent networks at the base by way of example fig2 to 6 illustrate three variants of the present invention in which the two shells 4 5 are formed by rotating hyperboloid bodies the base surfaces of which are occupied by the networks 1 2 of the exchanger batteries on a straight cross section of the tower at a certain height from the ground 6 vertical props 7 support the metal grating 8 supporting the networks in fig2 the two shells 4 5 both the same height are of concrete and each rests on a crown of oblique props 9 10 by means of a circular lintel 11 12 the cold air arrives as indicated by the arrows at the base of the tower between the different support props and is heated as it passes through the two concentric networks 1 2 to be subsequently eliminated out the top of the shells each flow of hot air is channeled by the partitions formed by the two shells 4 5 so that there can be no interaction between one flow and the other maintenance of the upward force of the hot air is thus ensured fig3 and 4 correspond to the preferred embodiment of the tower for the implementation of the method of the present invention in which the outer shell 4 is of concrete and rests.