RACA Journal February 2020 | Page 49

Getting Technical Furthermore, as many protagonists of NCWT have been claiming since simple permanent magnets were first used in the early 1900s, calcium carbonate crystals resulting from applied or induced magnetic fields tend to appear as the ‘aragonite’ type rather than the normal calcite type which precipitates from untreated water. Examples of these two types of crystals are shown in Figures 1 and 2 (courtesy of i-Cool Africa, suppliers of Enigma NCWT products). A claimed secondary effect of this increased crystallising rate is an increase in the ‘solvency strength’ of the water because it has become less saturated and therefore it now has additional solubilising capacity to dissolve and remove existing deposits of scale. Re-dissolving and removal of existing scale has been demonstrated in many field applications of NCWT units. However, curiously, there have been no accompanying water chemistry tests confirming that increased dissolving capacity of the water was, in fact, the mechanism which occurred. Two further aspects which Cho et. al have investigated are the applied AC electrical characteristics which produce the electromagnetic fields and the time spent by flowing water volumes exposed to the fields. These parameters cannot be www.hvacronline.co.za accurately determined to cover all water qualities, but the optimum AC voltages appear to be relatively low, ranging between 12 and 24 volts at frequencies varying over a wide range from kilohertz to megahertz. Also, ‘sharp’ alternating pulse configurations modulating across a wide range of amplitudes are more effective than smoother sine wave type conformations. It has not been possible to quantify optimum time periods for exposure of flowing water to alternating electromagnetic fields, but experimental results have consistently indicated that less than one second is sufficient provided that all water flow is perpendicular to a section of the induced magnetic field vectors. Increasing the exposure time does not appear to be more effective. However, on some larger volume water circuits, installing additional NCWT units at different points in the circuits has been shown to provide more uniform effects throughout the circulating water volume. Cho et. al would seem to have addressed most of the major concerns of critics of NCWT including considerations of variances in water flow rates. The British NCWT product, Scalewatcher now designated as ‘Enigma’, is a direct derivation from Cho’s work Continued on page 49 RACA Journal I February 2020 47