DC inverter, built-in Gree DC Inverter compressor, titanium tube +PVC cover heat exchanger, excellent anticorrosion performance and efficient heat transfer capacity, fashion appearance, R32 environment protection refrigerant, high energy efficient, the highest COP up to 6.1, wide operating range, it can normal work on -10 degree, it has automatic defrost function, the full intelligent controller can independently adjust the operating frequency of the heat pump according to the current water temperature and ambient temperature, so as to generate the maximum heat with the least power consumption.