This thesis develops a peers-to-peers intelligent air conditioner (A/C) controller which integrates the power line carrier technology and the infrared remote control. The intelligent air conditioner controller is used for the remote temperature setting and load control of air conditioner without requesting extra communication line and modification of the control circuit in the A/C unit. With the A/C controller developed the demand response in residential and commercial areas can be achieved effectively by reducing the peak power demand of A/C units. In order to investigate the PLC signal transmission over the low voltage distribution lines, the mathematical model of low voltage distribution system under high carrier signal frequency is derived. The computer simulation is executed to analyze the transmission characteristics of power line carrier signal. The proposed controller can receive the command issued by the demand response control center over the distribution lines with carrier frequency to execute the remote temperature setting of A/C units. Based on the field measurement of energy by air conditioner, it is found that significantly power demand reduction of air conditioner has been resulted by applying the proposed controller for remote temperature setting of air conditioner.