Air conditioner

A heat-pump type air conditioner operative in both a heating mode and a cooling mode, comprising:

• a compressor;
• a four-way change-over valve for reversing a refrigerant flow direction through a switching operation thereof;
• an outdoor heat exchanger;
• expansion valve means having a controllable opening degree for regulating refrigerant flow during both the heating mode and the cooling mode,
• means for controlling said expansion valve means so as to have an excess of opening degree during heating mode, thereby reducing noise produced by circulating refrigerant;
• indoor heat exchanger;
• and
• an auxiliary pressure reducing member which is provided between said expansion valve means and said outdoor heat exchanger and compensates for the resistance value produced by the excess opening degree of said expansion valve means.

A heat-pump type air conditioner operative in both a heating mode and a cooling mode, comprising;

• a compressor;
• a four-way change-over valve for reversing a refrigerant flow direction through a switching operation thereof;
• an outdoor heat exchanger:
• expansion valve means having a controllable opening degree for regulating refrigerant flow during both the heating mode and the cooling mode;
• indoor heat exchanger;
• and
• an auxiliary pressure reducing member which is provided between said electric expansion valve and said outdoor heat exchanger and compensates for the resistance value of said expansion valve means;
• a pressure reducing member which is disposed in parallel to said expansion valve means and serves to provide resistance to refrigerant passing therethrough, wherein the resistance value of said pressure reducing member is set to be smaller than the resistance value to be provided to the refrigerant in accordance with the opening degree of expansion valve means when the room heating operation is stopped.