2)Twice heat-exchange system ( Single copper coil )
3) Twice heat-exchange system ( Double copper coil )
4)inner tank use enamel coating
5)Use the high efficency heat pipe with 0.7mm thickness
6)Use intelligent pump working station
7)Outer tank:color steel with 0.5mm thickness
8)frame and outer manifold box of the collector use Alumimum alloy