Air conditioner coolant circulation route changing apparatus

An air conditioner having dual functions of heating and cooling and including a compressor for compressing a coolant into a coolant of high temperature and high pressure, an outdoor heat-exchanger for condensing the coolant of the compressor, a cooling capillary tube for expanding the condensed coolant at the outdoor heat-exchanger, an indoor heat-exchanger having a coolant inlet and a coolant outlet for changing the coolant into a perfect gas coolant of low temperature and low pressure and for heat-exchanging the coolant with room air and a coolant conducting arrangement for changing the coolant circulation direction of the coolant flowing inside of the indoor heat-exchanger, regardless of heating or cooling operation, from inside of the indoor unit to the room air suction side, which coolant circulation constitutes a reverse direction to that of the air flowing into the indoor unit, the coolant conducting arrangement comprising:

• a first conduit extending from the capillary tube to the inlet for the indoor heat exchanger;
• a second conduit extending from the outlet of the indoor heat exchanger to the compressor;
• a first solenoid valve disposed in the first conduit;
• a second solenoid valve disposed in the second conduit;
• a first coolant tube having a first end thereof connected to the second conduit at a location downstream of the second solenoid valve, and a second end connected to the first conduit at a location between the first solenoid valve and the inlet of the indoor heat exchanger;
• a second coolant tube having a first end thereof connected to the outlet of the indoor unit at a location upstream of the second solenoid valve, and a second end thereof connected to the first conduit at a location between the first solenoid valve and the capillary tube;
• a third solenoid valve disposed in the first coolant tube between the first and second ends thereof;
• a fourth solenoid valve disposed in the first coolant tube between the first and second ends thereof;
• a first checking valve disposed in the first coolant tube for permitting coolant to flow only in a direction from the first end to the second end of the first coolant tube;
• and
• a second checking valve disposed in the second coolant tube for permitting coolant to flow only in a direction from the first end to the second end of the second coolant tube;
• the first and second solenoid valves being open during a cooling operation and closed during a heating operation;
• the third and fourth solenoid valves being open during the heating operation and closed during the cooling operation.