The lining of the water tank is usually made of stainless steel or enamel.
Most of them now use stainless steel coating. The water tank is insulated with polyurethane foam. There are also better ones. For example, a German solar company not only uses polyurethane for insulation, but also encapsulates the top of the water tank with paraffin wax. Today, the domestic Soler Sunshine has also started to do this.
All in one. The split solar water heater separates the collector and the water tank and is suitable for a variety of architectural styles and installation locations. The monobloc system is more energy efficient. The water tank and heater are combined, eliminating the intermediate water circulation link and reducing water heat loss, so the one-piece system saves electricity. Integrated solar energyée is a solar energy in which the water tank and the collector are connected together.