of the medium temperature heat sink a third embodiment of the rotary valve 7 according to the invention illustrated in fig4 to 9 differs from the example embodiment of the rotary valve 7 illustrated in fig1 and 2 in that the rotary valve 7 is provided for three connected sorption modules 1 2 and 3 in that the rotor has six axial ducts and in that the two sorption modules to be cooled respectively in the adsorption mode are switched serially from the feed msv of the medium temperature heat sink to the return msr of the medium temperature heat sink the rotor of the rotary valve 7 has several for example two ducts 12 which lead forward two switching steps respectively in relation to the rotor rotation direction 9 the ducts 12 therefore in the axial traversing of the rotor have an offset forward so that in the first and the second rotor position the return of the first sorption module 1 to be cooled in the adsorption mode is switched via the rotor to the feed of the next sorption module 2 accordingly in the third and fourth rotor position the sorption modules 2 and 3 and in the fifth and sixth rotor position the sorption modules 3 and 1 are switched the rotary valve has two switch positions the first switch position corresponds to a cross switching and the second switch position corresponds to a regular switching the first third and fifth rotor position i e the odd numbered rotor positions form respectively a cross switching therefore correspond to the first switch position the second fourth and sixth rotor position i e the even numbered rotor positions form respectively.