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promoted as necessary for effectivemicrobial control. However, properly
applied sodiumhypochlorite programsworkwell at a fraction of the cost.
Inmany situations, themore expensive products are overfed or otherwise
misused. Another commonly observed problem is the over dosing of
phosphate and phosphonate inhibitors. This is problematic because the
limiting nutrient for microorganisms in water systems is almost always
phosphate; overfeedofphosphateand/orphosphonateproductsaggravates
microbial fouldingby fertilizing it (McCoy2005).
Pilot-scaleCoolingTower (PCT)
Pilotcooling towers(PCTs)havebeenused tosimulateall theprocesses
in open recirculating cooling tower systems. PCTs provide a means for
well-controlled scientifically defensible comparisons of microbial control
programs. Any situation encountered in the real world of HVAC cooling
forbuildingwater systems canbe simulatedand studies in thesepilot-scale
cooling towers.
