A refrigeration system comprising: a closed-loop refrigeration circuit including a compressor, a condenser, an expansion device, and an evaporator arranged in fluid communication such that a refrigerant is configured to cycle there through; and a free cooling system including: a free cooling heat exchanger; a closed-loop fluid cooling circuit thermally and hydraulically coupled to the evaporator of the refrigeration circuit such that a cooling fluid of the fluid cooling circuit is configured to transfer heat to the refrigerant; a closed-loop free cooling circuit thermally and hydraulically coupled to the condenser of the refrigeration circuit such that a free cooling fluid of the free cooling circuit is configured to absorb heat from the refrigerant, the free cooling circuit and the fluid cooling circuit being thermally and hydraulically coupled through the free cooling heat exchanger configured to transfer heat from the fluid cooling circuit to the free cooling circuit; and at least one valve (VI, V2) configured to control a flow through the free cooling heat exchanger within the free cooling circuit, wherein the refrigeration system is configured to operate in free cooling mode, a mechanical cooling mode, and a combined free cooling and mechanical cooling mode. a closed-loop refrigeration circuit including a compressor, a condenser, an expansion device, and an evaporator arranged in fluid communication such that a refrigerant is configured to cycle there through; and a free cooling system including: a free cooling heat exchanger; a closed-loop fluid cooling circuit thermally and hydraulically coupled to the evaporator of the refrigeration circuit such that a cooling fluid of the fluid cooling circuit is configured to transfer heat to the refrigerant; a closed-loop free cooling circuit thermally and hydraulically coupled to the condenser of the refrigeration circuit such that a free cooling fluid of the free cooling circuit is configured to absorb heat from the refrigerant, the free cooling circuit and the fluid cooling circuit being thermally and hydraulically coupled through the free cooling heat exchanger configured to transfer heat from the fluid cooling circuit to the free cooling circuit; and at least one valve (VI, V2) configured to control a flow through the free cooling heat exchanger within the free cooling circuit, wherein the refrigeration system is configured to operate in free cooling mode, a mechanical cooling mode, and a combined free cooling and mechanical cooling mode. a free cooling heat exchanger; a closed-loop fluid cooling circuit thermally and hydraulically coupled to the evaporator of the refrigeration circuit such that a cooling fluid of the fluid cooling circuit is configured to transfer heat to the refrigerant; a closed-loop free cooling circuit thermally and hydraulically coupled to the condenser of the refrigeration circuit such that a free cooling fluid of the free cooling circuit is configured to absorb heat from the refrigerant, the free cooling circuit and the fluid cooling circuit being thermally and hydraulically coupled through the free cooling heat exchanger configured to transfer heat from the fluid cooling circuit to the free cooling circuit; and at least one valve (VI, V2) configured to control a flow through the free cooling heat exchanger within the free cooling circuit, wherein the refrigeration system is configured to operate in free cooling mode, a mechanical cooling mode, and a combined free cooling and mechanical cooling mode.