Abstract: The invention relates to a refrigeration installation (1), to a method for same, and to a refrigeration installation system, for controlling the temperature of air, comprising at least one compressor (3), at least one expansion element (39) , and at least one first (5) and a second (7) heat exchanger, each of which can be operated as a condenser or a gas cooler, wherein at least one of the heat exchangers can be operated as an evaporator or at least one additional heat exchanger is provided which can be operated as an evaporator. A refrigerant line is equipped with a first valve (11) downstream of at least one compressor (3) at or downstream of a branch (9) and upstream of or at the condenser or gas cooler inlet (15) of the first heat exchanger (5), and a second valve (19) is arranged at or downstream of the condenser or gas cooler outlet (17) of the first heat exchanger (5) and upstream of or as an expansion element.