Cooling or heating systems that use water can dissipate heat acquired by the liquid with one of two methods — closed loop or open loop. The critical difference between these is the amount of exposure the water has to the air.
A closed circuit system encloses the water entirely within the pipes to preserve water volume and quality. Due to the lower maintenance requirements of a closed system, this type may see reduced costs over time compared to a higher maintenance open circuit system.
While sometimes more economical to install, open systems can have numerous problems with contaminants getting into the water of the cooling tower. Depending on the temperature, water can also evaporate from or freeze in the open cooling tower.
The water in your cooling or heating system dramatically affects the system’s performance. Monitoring and treating the water in the cooling mechanism will reduce problems caused by water deposits. Monitoring the water quality of your cooling or heating system may not be a task you have the experience or equipment to do yourself, but you can get expert service from the professionals at Chardon Laboratories. Before you request a quote, you should understand how your system works and why water treatment is vital to maintaining it.
Closed loop systems have a reduced chance of contamination, but they are not maintenance-free. NeClosed loop water systems have a reduced chance of contamination, but they are not maintenance-free. Neglecting the maintenance of a closed system promotes the growth of sludge and deposits. The most common problem with these systems is black magnetic iron oxide mud deposits. Over time, magnetic iron oxide particles bind and collect on narrowed parts of the system. The most common places for this sludge include:
Other problems can arise as the pH level of the water drops. A decreased pH can signal bacterial growth or a system leak, affecting both the water levels and chemistry. In addition to leaks, bacteria or mineral deposits can reduce the ability of the system to transfer heat by coating the surfaces of the parts. Regular care of your components through water testing and chemical maintenance prevents the corrosion of the system’s interior components.
While open systems need monitoring of water levels and observation for particulate matter from the environment, closed circuit systems need control of the water’s chemistry. Treating the water to prevent corrosion and freezing is part of maintaining these systems.
Proper closed loop water treatment should begin before the new system starts up for the first time. Once the closed loop system begins operation, you will not see the results of corrosion until the system shows signs of failure. That’s why most water treatment services aim to prevent corrosion, scale and microbiological growth.
In theory, a closed loop system should never leak. However, microbiologically influenced corrosion (MIC) can quickly lead to closed loop leakage in untreated systems. Before adding water treatment, on-site personnel should flush the closed loop system to prevent bacteria from colonizing on the iron surfaces. This cleaning and flushing process is a highly effective defense against MIC.
The use of water treatment chemicals in closed loop systems prevents corrosion in numerous ways. The proper chemical treatment can:
From complete cleaning and flushing to minor preventive maintenance, all treatments administered by ISO-certified technicians can help prolong the system’s life span.
A manufacturer in Eastern Ohio had an abundance of calcium carbonate scale buildup in its cooling towers due to the area’s hard water. The facility was receiving water from a well that varied in quality throughout the year and contained significant amounts of alkalinity and calcium hardness. To resolve this issue, Chardon Labs removed the scale using a foaming acid procedure and created a detailed water treatment program to ensure the correct amounts of chemicals were fed into the system.
Equipment is also essential in developing an effective water treatment program, which is why we recommended using the MegaTron MT Controller for better control of chemical feed and other system aspects.
A commercial printer in Central Ohio experienced high levels of copper discharge in the 4-6 parts per million (ppm) range — while the municipal baseline was 2 ppm. These high rates of copper contributed to less efficient heat transfer and galvanic corrosion. The company’s cooling tower make up water line was made of copper, which facilitated the increased copper in the water due to recirculation. Additionally, the rapid water flow rate within this piping caused erosion that released copper ions into the water.
Chardon assisted with this issue by installing a flow regulator, updated backflow preventer and solenoid valve to slow down erosion, bringing copper levels to below 0.03 ppm in a few weeks. In cases like these, monitoring make up water is essential to detect any problems early.
A plastics manufacturer in Northern Indiana experienced frequent buildup of debris and bacteria that was causing clogged filters, inefficiencies in heat transfer and dirty sumps. If these types of issues compound, they can commonly trigger shutdowns, affecting productivity and business reputation. Chardon addressed this problem by installing a centrifugal separator to keep the cooling tower basin clean and control bacteria like Legionella.
In weeks, the tower saw an increase in water quality, which prompted the manufacturer to install the separators at their other locations due to the devices’ effectiveness.
Abundant growth of bacteria, algae and fungi on surfaces can lead to microbiological fouling in cooling water systems. These microbiological problems usually develop more quickly and are more extensive in open loop systems. However, closed recirculating systems have an equal potential to support microbial growth, corrosion and fouling deposits.
When left unchecked, microbiological growth can quickly form a biofilm on wetted surfaces. This formation of microbial biofilms allows both aerobic and anaerobic bacteria to flourish, adversely affecting equipment performance, accelerating wood deterioration and promoting metal corrosion.
The control of biological agents, like bacteria and algae, is vital to any effective cooling water treatment. Biocides make it possible to control such factors, with two classes of biocides available:
It is crucial to control bacterial levels in closed water systems from the point of the first fill. Flushing and chemical pretreatment are necessary to keep bacteria, algae and fungi from proliferating on pipe surfaces.
Several sectors take advantage of more efficient closed circuit cooling systems. These industries need to invest in a system that will operate at its peak and require lower maintenance levels throughout the year. Manufacturers, hospitals, industrial facilities and many other businesses and industries embrace the long-term efficiency and savings of closed loop technology. Effective water treatment ensures that your closed-loop technology remains fast and effective, especially for industries that cannot risk extensive damage or prolonged downtime.
Industries often need backup plans in the event of power losses. Some facilities require generators to keep the lights on, whereas others need an emergency cooling system to continue process and component cooling if the primary mechanism fails. Closed loop water treatment is essential for many industrial emergency systems that rely on cooling water.
For instance, backup power generators used for commercial structures like hospitals or industries typically have closed loop systems. The engines in these generators don’t require regular use, but they will need a cooling system when in operation. The increased efficiency of a closed circuit system receiving proper water treatment ensures the generator has adequate cooling water and is always ready.
Nuclear facilities and other power plants use closed loop water cooling for safety and non-safety components. Thanks to multiple cooling paths, the various parts of a plant remain at a safe operating temperature. In nuclear facilities, redundant cooling mechanisms are critical to the safety of the plant. If the plant experiences a loss of its primary cooling, the closed loop system allows for continued heat removal. Like backup generators in hospitals, closed loop systems for nuclear power plants must always be ready to engage fully in an emergency.
Closed loop systems have uses for more than just emergencies. Many industries use these for process cooling — for instance, most food and beverage processing plants use open cooling towers for process chilling. However, some plants have chosen more energy- and water-efficient closed loop systems for chilling. These facilities may use adiabatic systems, which apply pressure changes to alter temperatures. Other similar closed loop systems are used near the beverage chillers for more efficient, more tightly controlled cooling for each separate process.
Closed circuit cooling systems also cool down components at a power plant. Water systems help cool bearings, while other coolers chill lube, air compressors and oil. At a power plant, the moving parts can generate enormous amounts of heat. Using a cooling water treatment can reduce the heat wear on these components, and a closed loop system cools them while requiring less maintenance over time.
Closed loop systems offer several advantages compared to open systems. While closed loop heating or cooling costs more initially, over time, that cost gets offset by the savings from better efficiency in all conditions. If you already have a closed loop system, you’ll feel you made a quality investment. Should you need to replace your existing open loop system, consider how a closed system can save you money — provided that you monitor and adequately treat the system over the years you use it.
Closed loop systems are more efficient than open systems. Since their design keeps the water enclosed inside the system, closed systems do not require additional water periodically to replace that which is lost from evaporation. Efficiency also increases in the winter when closed loop systems can operate dry, preventing freezing during the colder months.
Their reduced need for maintenance means that you will benefit from lower maintenance costs and longer system operation. Because closed loop systems don’t need a separate heat exchanger as open systems do, they also take up less space in your facility. While you should not cease all care for your system, as periodic maintenance is still vital for efficient operation, closed circuit designs will require fewer checks throughout the year.
To further save energy, closed circuit cooling systems allow for pump speed changes. Lowering the pump speed can conserve energy when cooling needs decrease. The flexibility to adjust to cooling and energy needs makes closed loop systems more energy-efficient. However, this is not the only way closed systems can adapt to changes.
Closed circuit cooling systems can demonstrate improved performance and efficiency compared to open systems. The closed circuit has four ways to adapt to cooling needs and outside temperature changes:
Adaptability makes closed systems a better option for variable climates, but ultimately the upkeep of the system will determine its cost over time. Luckily, closed loop systems have a design that reduces the need for regular, rigorous cleaning and maintenance. Effective pretreatment defends against the majority of closed loop system concerns.
Closed loop systems do not have an opening to the air, but this does not mean the system has complete protection from foreign matter in the water. Reducing the contaminants and debris in the system extends the entire system’s life by lengthening the amount of time before components need replacements.
Thanks to the closed design, the system can go weeks between chemical treatments with well-treated and monitored water. In a system without any leaks, regular closed water systems monitoring and treatment should suffice to minimize pollutants. However, if you neglect the system for too long, it can develop leaks, which make it harder to maintain.
To prevent corrosion in carbon steel components, the water must maintain a high or alkaline pH. To keep the correct chemical balance, water treatment professionals such as the experts at Chardon have several options at their disposal:
These substances are not the only options for maintaining a closed loop system, but they are a sampling of the products maintenance professionals could use.
Don’t neglect your closed loop water system — it still needs water treatment like open loop systems do. Regular treatment of the water and the system itself will ensure it continues to operate flawlessly for years. Without routine care, your water could cause corrosion or excessive mineral deposits on the parts of the closed loop system. These conditions can quickly deteriorate your system without you knowing until efficiency drops to detectable levels.
To prevent serious harm from untreated water, you need frequent treatment of the system and its contents. Your closed water system will need an expert to change the filters, conduct pH balance checks and perform maintenance checks. At Chardon Labs, we can help with these tasks and many others.
We have water treatment professionals who know the right way to balance the water chemistry in your system, and we won’t sell you chemicals. We provide you with a clean system via our expert maintenance. For more information about our water treatment and system maintenance, contact us today. We want to help you get a clean system that will last.
