Otherwise, if the inequality is not satisfied, one can presume that small decrement of heat rejection pressure will yield much more power consumption saving than decrement of cooling capacity so that COP will be raised with decrement of the heat rejection pressure. This represents how the suggested real time controller operates. In this study, the introduced concept of control method was implemented and its results were analyzed. Moreover, the errors which are caused by the introduced assumptions which do not reflect the real system behavior were discussed.