Conventional power system structure needs innovations to increase efficiency, reliability and participation of renewables. Smart Grid provides worthy solutions for achieving these goals. Between these solutions, the interest on Demand Side Management (DSM) options has increased in recent years. Improvements can be made in the intelligence of Demand Response (DR) to increase the benefits of DSM. The controller and the strategy going to be used for Intelligent Demand Response (IDR) need particular attention. In this study, different strategies for control of thermostatic loads are evaluated. Models of refrigerators with different energy efficiency classes are used in simulations to analyze the DSM potential. Various strategies were compared from the perspectives of demand changes in peak periods, savings in annual energy bills, changes of yearly energy consumptions and times of controller intervention.