fig7 shows a device 10 which is structured essentially like the device as shown in fig5 however as shown in fig7 the bypass line 120 is made in a direct continuation of the line 124 furthermore in the bypass line 120 there is no valve so that the flow of heat transfer medium is conveyed essentially by the heat exchanger 86 heating and cooling on the heat exchanger 86 are controlled solely by the corresponding operation of its fan the heating cooling surfaces 92 and 100 are connected in parallel to the bypass line 120 analogously to fig5 finally fig8 shows the device 10 in which in the line 52 of heat transfer medium circuit 14 a branch 126 is formed from which a line 128 leads continuously to a branch 130 which is located in the line 80 at the outlet 82 in the device 10 as shown in fig8 furthermore in the flow direction downstream of the branch 126 proceeding from the triple junction 136 a parallel connection is formed from the line 134 the line 136 and the line 138 in the line 138 there are a valve 140 and the heating cooling surface 92 the line 136 extends continuously from the branch 132 to a branch 142 at which the three lines 134 136 and 138 come together the parallel connection of the three lines 134 136 138 selectively enables flow through the heat exchanger 86 direct diversion to the reservoir 34 and or flow.