... solar hot water Manufacture since 1987SRCC,Solarkeymark approvaltesting 100% in houseAnnual capacity 1000,000setssolar hot waterSolar water heater,solar hot water,solar water heating,solar heatingModel ... For the system with double coils in tank,it can operate with traditional heating energy ... work normally under -35C.Detail Specifications:1). Inter-tank: Super SUS304 stainless steel & thickness:1.2 ...