Economizer cooling temperature protection

A method of operating a cooling loop having a compressed refrigerant mode and a pumped refrigerant mode, the method comprising:

• operating the loop in the pumped refrigerant mode when a cooling demand is less than a threshold, wherein operating the loop in the pumped refrigerant mode comprises allowing a temperature to vary within a first range;
• operating the loop in the compressed refrigerant mode when the cooling demand is greater than the threshold, wherein operating the loop in the compressed refrigerant mode comprises allowing the temperature to vary within a second range, wherein the second range is wider than the first range;
• and
• switching from the pumped refrigerant mode to the compressed refrigerant mode when the temperature meets or exceeds a limit.

A method of operating a cooling loop having a compressed refrigerant mode and a pumped refrigerant mode, the method comprising:

• monitoring a setpoint temperature, a measured temperature, a first time period, a first offset temperature and a second offset temperature, wherein the first offset temperature and the second offset temperature are greater than the setpoint temperature, and wherein the second offset temperature is greater than the first offset temperature;
• operating the loop in the pumped refrigerant mode when the measured temperature is less than the first offset temperature;
• when the measured temperature reaches the first offset temperature, continuing to operate the loop in the pumped refrigerant mode for the first time period;
• and
• switching from the pumped refrigerant mode to the compressed refrigerant mode before the measured temperature exceeds the second offset temperature.