Notice of Retraction: Research on Theory and Performance of Ducted Air-Conditioning (AC) Unit

At present, ducted air-conditioning (AC) unit is characterized of high efficiency, convenient installation, fresh air, less initial investment, etc. It has been widely used in restaurant, supermarket and factory workshop. This paper analyses advantage and disadvantage of the capillary tube, single ported thermostatic expansion valve, double ported thermostatic expansion valve. Especially, modern large-scale buildings make indoor and outdoor unit' placing distance very far, how to ensure reliable running of the system of long tube is important, and proposed a method that making the balanced port thermostatic expansion valve and capillary tube run parallel connection, which ensuring reliable operation of the system of long tube.