Scale formation in Evucuated solar glass tubes

Generally, problem of scale formation was frequently observed in Copper Collectors of Flat Plate Collector (FPC) based solar water heaters in areas where hard water is used directly to heat water as diameter of Riser pipe (copper pipe) in copper collector is 13 mm. But we have come across this problem in rare cases in old Evacuated Tube Collector (ETC) solar water heaters with tube dimension : Outer Diameter: 47 mm, Inner Diameter: 37 mm and Length: 1800 mm.

Customer can’t get proper hot water temperature due to problem of scale formation in copper collectors or solar glass tubes.

Hard water is detrimental to the life of solar water heaters in India as we can find excessive hard water in some areas. Site Servicing of solar glass tubes blocked due to scale formation is easy Compared to Copper Collectors  blockage.

Hence new technology of Evacuated Tube Collector (ETC) solar water heaters gives advantage to manufacturer, supplier and customer as solar glass tubes can be serviced on site itself, whereas in case of FPC solar water heaters installed in areas of high TDS level, supplier of solar water heater has to dismantle the Copper Collectors installed at site and sent these Collectors for Descaling to workshop or manufacturer premises as Copper Collectors are totally blocked in these cases just like Vein of human being is blocked in case of severe heart attack. We can say Solar water heater is affected by heart attack as its heart (Copper Collectors) is blocked due to scale formation which prevents water being heated by solar energy.

Cost of servicing of solar glass tubes is quite cheaper compared to Copper Collectors of FPC solar water heaters.

You can have a glimpse of scale formation in solar glass tube:


Above is Broken solar glass tube with scale formation.


You can see scale removed from tube in Powder Form lying on the tiles near solar tube.

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