An apparatus for recovering refrigerant from an air conditioning system , said apparatus comprising: - an evaporator arranged to receive said refrigerant from said air conditioning system and separating said refrigerant from impurities in it present, obtaining purified refrigerant; - a compressor for circulating said purified refrigerant exiting from said evaporator ; - a condenser in hydraulic connection with said compressor , said condenser arranged to condense the refrigerant exiting from said compressor ; - a storage container in hydraulic connection with said condenser , said storage container arranged to contain the refrigerant condensed by said condenser , said storage container defining a storage chamber arranged to contain a liquid phase of said refrigerant and a gaseous phase comprising a vapour component of said refrigerant and an air component , and having a purge opening ; characterized in that said apparatus provides a purging device comprising: - a measuring means configured to measure operating parameters of said refrigerant present in said storage chamber ; - a purge means arranged at said purge opening configured to purge said gaseous phase present in said storage chamber from said air component ; - at least a first separation chamber connected to said storage container ; - a selective passage means arranged at said opening between said storage chamber and said first separation chamber arranged to separate said gaseous phase into said vapour component of fluid and into said air component in such a way that through said selective passage means only said air component and a reduced amount of said vapour component enter said first separation chamber . - an evaporator arranged to receive said refrigerant from said air conditioning system and separating said refrigerant from impurities in it present, obtaining purified refrigerant; - a compressor for circulating said purified refrigerant exiting from said evaporator ; - a condenser in hydraulic connection with said compressor , said condenser arranged to condense the refrigerant exiting from said compressor ; - a storage container in hydraulic connection with said condenser , said storage container arranged to contain the refrigerant condensed by said condenser , said storage container defining a storage chamber arranged to contain a liquid phase of said refrigerant and a gaseous phase comprising a vapour component of said refrigerant and an air component , and having a purge opening ; - a measuring means configured to measure operating parameters of said refrigerant present in said storage chamber ; - a purge means arranged at said purge opening configured to purge said gaseous phase present in said storage chamber from said air component ; - at least a first separation chamber connected to said storage container ; - a selective passage means arranged at said opening between said storage chamber and said first separation chamber arranged to separate said gaseous phase into said vapour component of fluid and into said air component in such a way that through said selective passage means only said air component and a reduced amount of said vapour component enter said first separation chamber . <EOS>