An air conditioning system having a cooling mode and a free-cooling mode, comprising: a refrigeration circuit having an expansion device, a compressor and a pump; a suction pressure sensor for measuring a suction pressure of said compressor; a controller for selectively operating in the cooling mode by circulating and compressing a refrigerant through said refrigeration circuit via said compressor or operating in the free-cooling mode by circulating said refrigerant through said refrigeration circuit via said pump; and a recover-refrigerant sequence resident on said controller, said recover-refrigerant sequence being configured to recover the refrigerant in a portion of said refrigeration circuit not used in the free-cooling mode to remaining portions of said refrigeration circuit used in the free-cooling mode when said controller switches from the cooling mode to the free-cooling mode, characterised by: a discharge pressure sensor for measuring a discharge pressure of said compressor; and a three-way valve; wherein said recover-refrigerant sequence is configured to: close the expansion device; adjust an alignment of the three-way valve so that said refrigerant is recovered from the portion of the refrigeration circuit not used during the free-cooling mode; activate the compressor until a suction pressure of said compressor equals a suction pressure threshold; and maintain said expansion device in a predetermined position until a pressure differential across said compressor reaches a threshold pressure differential. a refrigeration circuit having an expansion device, a compressor and a pump; a suction pressure sensor for measuring a suction pressure of said compressor; a controller for selectively operating in the cooling mode by circulating and compressing a refrigerant through said refrigeration circuit via said compressor or operating in the free-cooling mode by circulating said refrigerant through said refrigeration circuit via said pump; and a recover-refrigerant sequence resident on said controller, said recover-refrigerant sequence being configured to recover the refrigerant in a portion of said refrigeration circuit not used in the free-cooling mode to remaining portions of said refrigeration circuit used in the free-cooling mode when said controller switches from the cooling mode to the free-cooling mode, characterised by: a discharge pressure sensor for measuring a discharge pressure of said compressor; and a three-way valve; wherein said recover-refrigerant sequence is configured to: close the expansion device; adjust an alignment of the three-way valve so that said refrigerant is recovered from the portion of the refrigeration circuit not used during the free-cooling mode; activate the compressor until a suction pressure of said compressor equals a suction pressure threshold; and maintain said expansion device in a predetermined position until a pressure differential across said compressor reaches a threshold pressure differential. a discharge pressure sensor for measuring a discharge pressure of said compressor; and a three-way valve; wherein said recover-refrigerant sequence is configured to: close the expansion device; adjust an alignment of the three-way valve so that said refrigerant is recovered from the portion of the refrigeration circuit not used during the free-cooling mode; activate the compressor until a suction pressure of said compressor equals a suction pressure threshold; and maintain said expansion device in a predetermined position until a pressure differential across said compressor reaches a threshold pressure differential. close the expansion device; adjust an alignment of the three-way valve so that said refrigerant is recovered from the portion of the refrigeration circuit not used during the free-cooling mode; activate the compressor until a suction pressure of said compressor equals a suction pressure threshold; and maintain said expansion device in a predetermined position until a pressure differential across said compressor reaches a threshold pressure differential.