... solar water heater supply hot water for factory, hotel, school, and so on. solar collector Working principle:Combined many collectors with water ... Stainless steel8. Option:controller, Electric heater, Magnesium rod.Popular model MODELAbsorbing Areavacuum tubeTankCapacity(m2)diameterlengthNo.(L)BN58 Vertical Series1.2Φ ... .2Φ 58mm1800mm404004Φ 58mm1800mm505004.8Φ 58mm1800mm60 industry solar water heater