Features: 1) It is equipped with imported specially produced semi-close dual-screwed-type compressor, adopts the third generation of 5-to-6 dissymmetrical tooth-shaped rotor to save the running energy, the patent design can reduce the air accumulation between high pressure and low pressure so as to ensure compressor keeps high efficiency running within wider scope 2( Heat abstraction coil adopts 3/8 high-efficient internal threaded copper tube and hydrophilic aluminum fin with corrugated edge and lancing. The designed heat exchanger area and flue and fin quantity are enlarged so as to make high pressure become lower when running in cold house and lower pressure higher when running in warm house, and ensure high-efficiency and energy conservation of the unit during running. The evaporating pressure and stable temperature can reduce the frosting when it runs in winter and thus the heat of the unit can be supplied for a long term 3) It adopts lateral vertical h-shaped row of tubes, superficial wind speed does not change much, air flow distributes uniformly. In order to adapt to continental climate, the spacing between heat abstraction fin is enlarged up to 2mm for purpose of defrosting in winter and guarantee good heat abstraction of the unit. Blue foil anticorrosive aluminum fin is used for the whole heat exchanger to ensure beautiful appearance. Changhong corporation and the state research institute and Beijing Qinghua University. It adopts aviation plasticizing materials and has unique fan blade structure 4) Leads a part of liquid refrigerant into compressor, and then cool down operating temperature of motor and rotor bearing of compressor and improve running state of the unit, so as to guarantee that the unit runs within normal scope under high-pressure running state and ensure that the unit runs normal under worse environment 5) The unit is equipped with the humanized LCD PLC operating interface in Chinese and the control system with perfect protective measures can monitor the running status of the unit. Special contacts are preset in the controlling box for the user to connect with remotely transmitted wire, and can connect with ports of computer or MODEM communication via RS-232 and RS-485 standard serial communication port 6) Controller with screen and sub-screen is available or big-screen color LCD with touch mode is available for the whole series