... Solar CollectorWork principle:The water in water tank is for heat preservation and circulation. The vacuum tube collector absorbs sunshine ... water flows through the inlet, the copper coil absorbs heat then transfer to the cold water, so that temperature rise up ... 0mm)4. Tank insulation: Polyurethane integral foaming, 55-60mm thickness5. Heat preservation time: 80 hours6. Wind resistance: 30-35m/s, ...