Patent ID: 7836711

Claim:
An air conditioner comprising a refrigerant circuit ( 20 ) wherein the refrigerant circuit ( 20 ) includes: a compressor ( 41 ); a utilization-side heat exchanger ( 53 ); and an expansion valve ( 52 ) for controlling the amount of refrigerant flowing into the utilization-side heat exchanger ( 53 ), to thereby perform a refrigeration cycle, and wherein the air conditioner performs a cooling operation for room cooling while during the cooling operation the air conditioner is able to execute an ice melting operation for melting of ice adhering to the utilization-side heat exchanger ( 53 ) by closing the expansion valve ( 52 ) to thereby feed air to the utilization-side heat exchanger ( 53 ), the air conditioner comprising: high-low pressure difference detection means ( 93 , 97 ) for detecting a difference between a high and a low pressure of the refrigeration cycle; temperature measurement means ( 54 ) for measuring either the temperature of a pipe line between the expansion valve ( 52 ) and the utilization-side heat exchanger ( 53 ) or the temperature of the utilization-side heat exchanger ( 53 ); and control means ( 81 ) for activating the ice melting operation to start if a predetermined start condition is met and for terminating the ice melting operation if the value of measurement taken by the temperature measurement means ( 54 ) continuously remains equal to or above a reference temperature (T 3 ) for a reference time (t 3 ); wherein, based on the value of measurement taken by the high-low pressure difference detection means ( 93 , 97 ), the control means ( 81 ) sets the reference temperature (T 3 ).