pre-heated solar water heater :
1)fine thermal characters
2)good heat conductivity
3) electricity boosters

pre-heated solar water heater being described as follows:

1) Vacuum collector tube : aluminum & steel &copper coating (three layers):

ø47mm/1500mm ø58mm/1800mm
2) Inner tank: SUS 304 2B food level stainless steel with the thickness above 1mm
3) Outer tank materials: Colored steel plate/stainless steel/wortle plate
4) Water Capacity: 120L/150L/200L/250L
5) vacuum collector Tubes quantity is open to options: 16/18/20/24/30

6)insulation material:polyurethene foam ,thickness 50-60mm
6) Bracket : colored steel/stainless steel/aluminum alloy (plane/level/astride)