Air conditioner

An air conditioning system that is comprised of an air cycle circuit (20) through which a primary air flows and configured to provide heating for a room by supplying a heated secondary air being heated through heat exchange with the primary air to the room, and the air cycle circuit (20) includes;

• a compressor (21), wherein the primary air is sucked and compressed;
• a heat exchanger (30), wherein the primary air being compressed by the compressor (21) exchanges heat with the secondary air;
• and an expander (22), wherein the primary air being exchanged with the secondary air in the heat exchanger (30) is expanded, the system further comprising
• dehumidifying means (55, 60) for dehumidifying the primary air so that the absolute humidity of the primary air is equal to or below the absolute humidity of an outside air, the dehumidifying means (55, 60) being disposed in a portion of the air cycle circuit (20) upstream of the expander (22).