... the heat of the water in the tank via the copper coil, therefore the water tank is just a heat storage tank.2.Specifications:Vacuum tube ... ,38o,45oCapacity of water tank: 100L,150L,200L,240L,300L,360L. 40L/person for Max consumptionAssistant tank: 5L, 8L, 10L, 12LCopper coil: With dia of ...