Abstract: The twin air conditioning system utilizes branch pipe components for mechanical flow separation, and the length of branch pipes connecting each indoor unit has a significant impact on the capacity of the indoor unit in that circuit. In order to ensure uniform distribution of refrigerant in each indoor unit and equivalent capacity output, theoretical analysis was conducted on the impact of branch pipe length on capacity, and experimental verification was conducted. Finally, it is suggested that the length difference of the split manifold during actual installation should be controlled within 8 m to ensure the stable operation of the twin air conditioning system.

Key words: Twin air conditioning system, Indoor unit capacity, Difference in length of branch pipes