Microbiological problems in cooling water systems cost businesses billions of dollars each year due to high energy costs, production losses, unscheduled maintenance, and replacement of corroded parts. Poor microbiological control can also lead to unsafe operating conditions, such as contamination by the bacterium that causes Legionnaires’ disease. While this article focuses on biocide contact time, there are many factors to consider when choosing the correct biocide, including:
In terms of raw energy efficiency and the ability to provide precise cooling under fluctuating load conditions, recirculating evaporative cooling water systems with chillers or heat pumps are the most efficient way to remove heat from a process or building air. However, adiabatic cooling systems can be a good fit with an overall lower cost for heat removal in some climates and applications.
Important Differences You Need To Know
Evaporative condensers are commonly used for heat rejection in low temperature ammonia refrigeration applications in cold storage and food processing plants. Although often confused with standard cooling towers, there are some key differences between evaporative condensers and the cooling tower systems used in HVAC applications. Understanding these differences and the challenges they present is important for water treatment program success.
Biofilm deposits are one of the most difficult challenges your cooling water systems face. They tend to start in areas not accessible to biocide treatments, and can quickly grow to form biofouling deposits that can cause corrosion damage, blockages, reduced heat transfer, and amplify the growth of Legionella bacteria. Once they become established, biofilms are incredibly tenacious and difficult to remove.
What You Need to Know
Chlorine and bromine based biocides are widely used for microbiological control in cooling tower systems. These halogen compounds form strong oxidizing agents in water, which is how they kill bacteria and other microorganisms. Routine testing is important to confirm effective halogen residuals are maintained. Low residuals can result in poor microbiological control. High residuals can cause corrosion and destroy inhibitors.