Water chiller

A water chiller comprising:

• at least one refrigeration apparatus,
• a water circuit in which circulates a water flow to be cooled down,
• at least one fan generating an air flow that is aspired from the outside;
• the refrigeration apparatus comprising a refrigerant circuit functioning in closed loop,
• the refrigerant circuit comprising a compressor, at least one condenser, an expansion valve and an evaporator,
• said condenser being configured to release heat from the refrigerant to the air flow under action of said at least one fan,
• said evaporator being configured to draw heat from the water flow to cool down said water flow,
• wherein the water chiller further comprises at least one free cooling heat exchanger, configured to be exposed to the air flow, and connectable to the water circuit,
• and wherein the water chiller comprises controllable air flow direction means adapted to selectively:
• direct the air flow away from said at least one free cooling heat exchanger, in a mechanical cooling configuration in which the refrigeration apparatus is running and said at least one free cooling heat exchanger is disconnected from the water circuit;
• or
• direct the air flow through said at least one free cooling heat exchanger, in a free cooling configuration in which the refrigeration apparatus is stopped and said at least one free cooling heat exchanger is connected to the water circuit.