SYSTEMS AND METHODS FOR CONTROLLING A REFRIGERATION SYSTEM

A refrigeration system (12) includes a free cooling system (52) having an air-cooled heat exchanger (56), where the air-cooled heat exchanger includes a fan (60) configured to move air (59) over coils of the air-cooled heat exchanger to remove heat from a coolant (58) flowing through the air-cooled heat exchanger, and a mechanical cooling system (68) with a refrigerant loop that includes an evaporator (66), a compressor (70), and a condenser (72) disposed along the refrigerant loop, where the compressor is configured to circulate a refrigerant through the refrigerant loop, and wherein the evaporator (66) is configured to receive the coolant and transfer heat from the coolant to the refrigerant. The refrigeration system (12) also includes a controller (78) configured to adjust a fan speed of the fan (60) up to a threshold fan speed, to initiate operation of the compressor (70) when the fan speed reaches the threshold fan speed, wherein the fan speed and a compressor speed of the compressor are based at least on an ambient air temperature (89) and a cooling load demand.