... in heat protection water tank. Features of Solar collector:1. The solar collector is more suitable for solar hot water project, because you can free ... No. Available Date-Expired Date Solar Keymark DIN 011-7S978 R Solar Collectors & JNSC15-58/1800, JNSC18-58/1800, JNSC20-58/1800, JNSC24-58/1800, JNSC30-58/1800 2012/07/11 --- 2014 ...