Any industry professional would quickly agree that water is the key ingredient to evaporative cooling water systems performance. For evaporative cooling equipment like cooling towers, evaporative condensers or fluid coolers, water quality is essential for proper heat transfer and the healthy service life of the equipment.
By association, that same water also is essential to operation of the water chillers, process equipment or building systems connected to the evaporative cooling equipment. Yet, some operators or building owners fail to recognize how the quality of the available makeup water and ongoing water treatment of the condenser water may impact equipment commissioning, operational water efficiency and lifespan of the equipment.
When evaporative cooling systems are commissioned, careful attention should be given to water quality during the initial fill. After commissioning, maintaining consistent water quality throughout the system is important for the health of the entire condenser water system.
In fact, it has been proven that makeup water quality and the consistency of water treatment programs have a direct impact on the performance of evaporative cooling systems. They affect efficiency, available uptime, maintenance needs and, ultimately, the equipment longevity.
To what extent? An owner’s first cost for an evaporative cooling system is often viewed as the deciding factor. However, a broader view that takes into account the two key factors — the quality of the available makeup water and the consistency of the water treatment program — can lead to a lower total cost of ownership.
When available makeup water quality and the consistency of treatment are ignored, bad water conditions can ruin a cooling system in as little as two to seven years. The same system could last 15 to 20 years if water quality is a part of the equipment selection process, and water treatment is consistently maintained.
Often, water is referred to as a universal solvent — a property that can cause unwanted side effects for industrial uses. Water dissolves many substances, including gases like oxygen and carbon dioxide. As a result, water can cause corrosion of metals.
Also, as water concentrates in an evaporative cooling system, dissolved ions may exceed the solubility of some minerals and form scale. Bacteria entering a system from the makeup water supply may grow in number, creating challenges related to fouling, corrosion or undesirable microbes like Legionella bacteria.
These problems highlight the importance of:
- Selecting appropriate materials of construction.
- Implementing an effective treatment program.
- Putting into a place a routine of preventive maintenance.
These three steps will help ensure efficient operation of cooling water systems and an appropriate service life for the equipment they serve.