Legionnaires’ disease is caused by the waterborne bacteria legionella, which is found in most water sources, including municipal drinking water, at levels that are below standard detection limits and not harmful. Legionella can grow to dangerous levels in systems that store water, including air conditioner cooling towers, ornamental water features, and hot water tanks. Any water that is cloudy or dirty can be considered to have an extremely high concentration of bacteria and also higher life forms like amoebae as well. Temperatures above 104° F promote rapid multiplication of the organism. The organisms are consistently found in the biofilm that forms in aquatic environments, cooling towers and potable water systems.
In cooling towers, temperature, water hardness, pH, scale and corrosion are all factors which increase the chance of biofilm, algae and Legionella colonization. Due to the favorable conditions such as relatively high water temperature and high nutrient content provided by the sediment of debris in a cooling tower basin, bacteria is commonly found in the condensing water circuit, which is not completely protected by biocides.
Biocides are typically maintained at a certain level in order to kill bacteria. However, real-time monitoring of biological activity is required to determine the extent the bacterial activity, which is expensive and often not frequent enough to identify elevated Legionella levels. Water is conventionally treated by chemicals, though bacterial growth normally cannot be stopped due to design and/or maintenance problems. The growth of bacteria leads to the formation of biofilm and health hazard issue. The high temperature of condensing water especially favors the growth of Legionella which is a major concern for commercial building operators and their visitors.
HydroFLOW Controls Legionella, Bacteria and Algae
Bacteria and algae that pass through the water conditioner's ring of ferrites becomes charged by the Hydropath signal. This charge forms a hydration layer of pure water around the cell. Osmosis forces water into the bacteria and/or algae, creating osmotic pressure, which ruptures the cell membrane and causes the cell to die. Legionella often embeds in algae growth in water systems, and HydroFLOW deactivates algae and bacteria throughout a system; often where chemicals do not consistently reach.
The Hydropath signal emanates in both directions of a water line, using the fluid to carry the signal. The sustained 150 kHz frequency prevents hard scale from forming and disrupts the bacteria and/or algae clinging to the rough inner surface, gradually releasing the biofilm over time.
There are many advantages to HydroFLOW water conditioning besides bacteria control, including:
Corrosion caused by scale deposits is eliminated
Energy use is greatly reduced due to heat exchange surfaces remaining
Free of scale deposits (¼-inch of scale increases energy costs by approximately 40 percent)
Extensive downtime and labor cost involved in descaling systems is eliminated
Legionella Case Studies
The water quality of a cooling tower system at a commercial facility in China continued to operate below standards for the first half year of 2008. Chemicals were changed frequently but failed to achieve a desired result. When Hydropath technology was used without the adding chemicals, the total bacteria count decreased to below 1,000CFU/mil and Legionella was no longer detected.
The Legionella count in a cooling tower system at a shopping mall exceeded the specified concentration limits despite regular chemical dosing applications. When Hydropath technology was applied, the bacteria count was maintained below action limits after scheduled testing.