the liquid state in the outlet section 6 the length of the liquid column can be determined by means of the choice of the length of the outlet section 6 and the installation height of the suction device 3 the suction effect in the suction section 5 is based on the suction pressure which is at least as large as the vapor pressure of the solvent 8 the vapor pressure of the solvent 8 is however smaller than the pressure in the absorber 11 or in the condenser 12 in any case the reason for this is the cooling occurring upon condensation or absorption of the heat pump medium 2 the method can be carried out without applying a pre pressure and only with the pressure formed by the difference in height between the inlet for the solvent 8 and the liquid state in the outlet section 6 fig4 shows a portion of the heat pump 1 in an embodiment in this embodiment gas present in the absorber 11 is removed this embodiment is advantageous because the absolute pressure level in the absorber 11 is lower than in the condenser 12 and the gas therefore preferably accumulates in the absorber the shown portion comprises the absorber 11 the suction device 3 the pump 15 the precipitator 40 a collection container 41 and a connecting pipe 42 for the connection with the dissolving heat exchanger 18 the solvent.