Demand side management techniques havedrawn significant attentions along with the development of smart grid. This paper proposes a new direct load control(DLC) model for scheduling interruptible air conditioner loads. The model is coordinated with the unit commitment and economic dispatch to minimize the total operation costover the whole dispatch horizon. The network constraints are also considered in the model. To ensure the thermal comfort of the occupants, we are among the first toincorporate the advanced two-parameter thermal inertiadynamical model of customer houses into the DLC modelto calculate the indoor temperature variation. This paperalso proposes a distributed imperialist competitive algo-rithm to effectively solve the model. The simulation studiesprove the efficiency of the proposed methodology.