To reproduce an air conditioner of which the performance has been deteriorated by a long period use, by recovering its heating/cooling performance while utilizing existing equipment, and to reproduce the air conditioner of which the performance has been deteriorated by a long period use as a new refrigerant air conditioner.

In this air conditioner, a second condenser 10 is additionally mounted between a condenser 1 and an expansion valve of an existing air conditioner, the condenser and a second condenser 10 are applied as air-cooled type heat exchangers, a refrigerant parallel flow system is applied in the additional second condenser, and the second condenser is disposed at the outside air suction side of the rear face of the existing condenser in an overlapped state. In this new refrigerant air conditioner, the second condenser is disposed at the outside air suction side of the rear face of the existing condenser in an overlapped state, the second condenser is equipped at a partial front part of the front face of the existing condenser, a refrigerant gas filled in the existing condenser is removed, and a new refrigerant gas is newly filled to reuse the existing equipment.