Temperature control system and method of operating the same

A system for conditioning air in a load space of a vehicle, the system comprising:

• a refrigeration circuit including an evaporator and housing refrigerant, the refrigeration circuit further including a throttle valve upstream of the evaporator;
• a first sensor positioned along the refrigeration circuit to sense a first condition, the first condition being a function of one of a temperature and a pressure of the refrigerant in the refrigeration circuit away from the evaporator;
• a second sensor positioned along the evaporator to sense one of a temperature and a pressure of the refrigerant in the evaporator;
• a controller determining a second condition based on the one of the temperature and the pressure of the refrigerant in the evaporator and to convert the one of the temperature and the pressure of the refrigerant in the refrigeration circuit away from the evaporator to determine the first condition, the controller further configured determine a position of the throttle valve, determining a difference between the first condition and the second condition, and initiating a defrost process of the evaporator in response to the throttle valve in a fully open position and the difference being greater than a threshold and wherein the controller determines a saturation suction temperature and to compares the saturation suction temperature with an evaporator coil temperature, and wherein the controller initiates the defrost process in response to the saturation suction temperature being less than the evaporator coil temperature.

A system for conditioning air in a load space of a vehicle, the system comprising:

• a refrigeration circuit including an evaporator and housing refrigerant, the refrigeration circuit further including a throttle valve located upstream of the evaporator;
• a first sensor positioned along the refrigeration circuit adjacent the throttle valve to sense a first condition of the refrigerant in the refrigeration circuit;
• a second sensor positioned adjacent the evaporator to sense a second condition of the refrigerant in the evaporator;
• and
• a controller determining a position of the throttle valve, a saturation suction temperature, and a difference between the first condition and the second condition, the controller further determining an evaporator coil temperature based on the second condition and initiaing a defrost process of the evaporator in response to the throttle valve in a fully open position, the saturation suction temperature being less than the evaporator coil temperature, and the difference being greater than a threshold.