Abstract: The invention provides a regenerative heat exchanger rotor with an outer casing which comprises a plurality of layers of a helically wound strip orientated so that its width direction is radial with respect to the rotor, a core on which the strip is wound and which is permeable for the medium with which the rotor is to be used, said strip having channels therein to allow the radial passage of the current of the medium. A further strip on the rotor is free of channels and is also wound on the permeable core helically so as to be associated with the channeled strip so that the layers or turns of the unchanneled strip (20) alternate with those of the channeled one with each layer or turn of the channeled strip being followed by one layer or turn of the unchanneled one. This arrangement makes possible an extraordinarily satisfactory efficiency as regards flow and heat transfer. This advantage is combined with the advantage of the possibility of very simple and cost-effective production.