1. A method for controlling a flow of a non-solid substance in a Variable Temperature Control (VTC) box in a temperature control system, wherein the VTC box comprises a heat exchange device under control of a regulation device, comprising: receiving an indication of a temperature setpoint; measuring a discharge air temperature of the VTC box and calculating an error between the temperature setpoint and the measured discharge air temperature; and until a new temperature setpoint indication is received, repeating the steps comprising: based on the error, predicting a regulation device position adjustment to actuate the regulation device to achieve the temperature setpoint, if the predicted regulation device position adjustment is less than a minimum position adjustment, not actuating the regulation device and measuring the discharge air temperature to calculate an average discharge air temperature over a period of time, if the predicted regulation device position adjustment is not less than the minimum position adjustment, measuring the discharge air temperature in the VTC box while actuating the regulation device the predicted position adjustment or until the discharge air temperature is measured to have crossed the temperature setpoint, in response to actuating the regulation device, measuring the discharge air temperature to calculate the average discharge air temperature, and based on the average discharge air temperature, recalculating the error.