solar water heater has a special copper coil heat exchanger in the inner tank;
CE;
EN12975;
Solar Keymark certification.

Pressure tube solar water heater with copper coil:

Features:
1) Designed to accept mains pressure cold water
2) Copper coil heat exchanger can be used as part of a closed or open loop system, providing heating to a main hot water tank
3) Freezing is of minimal concern for SFD series
4) Reliable, efficient, twin-glass solar tubes
5) Superior heat preservation with 50 - 65mm polyurethane tank insulation
6) Outer tank material: stainless steel plate or powder coated color steel sheet
7) Inner tank material:
    a) 0.5mm thick SUS304 food grade stainless steel plate
    b) High purity copper for the heat exchanger coil
8) Frame material: 1.2mm thick all stainless steel
9) Collectors may be connected in series to increase water heating capacity
10) Easy plug-in installation;