Abstract: The method and apparatus are for controlling an amount of power supplied to a conditioning device acting on an actual value of a predetermined physical parameter within an area in relation to a setting signal. The method comprising steps of monitoring the setting signal to detect a change thereof, and when a changed setting signal is detected (i) determining a time period and a uniform amount of power required by the conditioning device to cause the actual value of the predetermined physical parameter to theoretically reach a new range of desired values corresponding to the changed setting signal, and (ii) establishing time-related upper and lower limit profiles HLV(t) and LLV(t) of the predetermined physical parameter for the time period determined in step (i).