REFRIGERANT CIRCULATION TYPE AIR CONDITIONING SYSTEM

PROBLEM TO BE SOLVED: To achieve a reduction in cost by reducing the length of piping as much as possible even in an air conditioning system using a plurality of outdoor units. SOLUTION: In this air conditioning system, an outdoor unit 1 and a room unit 2 are arranged in a building so as to position the outdoor unit 1 above the room unit 2 while the both are interlinked by a refrigerant piping to circulate a refrigerant by a difference in specific gravity between a refrigerant liquid mainly liquefied by the outdoor unit 1 and a refrigerant gas vaporized by the room unit 2. In this system, a plurality of outdoor units 1 are arranged in the building at positions above the room unit 2 and are connected in parallel to a main refrigerant liquid piping 3 and a refrigerant gas piping 4 while a plurality of room units 2 are connected in parallel to the refrigerant liquid piping 3 and the refrigerant gas piping 4. Thus, even when a plurality of outdoor units 1 are arranged, the main refrigerant liquid piping 3 and the refrigerant gas piping 4 are used in common to circulate the refrigerant. This enables shortening of the piping as much as possible to simplify application work thereby achieving a reduction of cost.