Drum kickers, soap sellers… they’ve been called many things. Water treatment specialists (probably their preferred name) are everywhere. As a mechanical contractor, many have knocked on our door. Since most large commercial buildings and industrial facilities in Memphis use mechanical water cooling/heating equipment, this industry is very competitive, but is water treatment really necessary? In this issue of Mechanical Matters® I am going to answer that very question and discuss several other important facts about water treatment services.
In this edition I want to answer three questions about water treatment:
What exactly is water treatment and is it necessary?
How does inadequate water treatment service affect mechanical equipment?
Are there energy savings with water treatment?
1. What exactly is water treatment and is it necessary?
Water treatment describes a process used to make water more acceptable for a desired end use. These can include use as drinking water, industrial processes, medical, and many other uses.
The objective of any water treatment process is to eliminate the existing components in the water, improving it for later use. (wikipedia.org)
In the mechanical industry, water treatment is a method used to optimize most water-based mechanical and industrial processes, such as: heating, cooling, processing, cleaning and rinsing, so as to reduce operational costs and risks. .
Most water treatment programs include water softeners, inhibitors, and other chemicals needed to ‘treat’ the water to the desired conditions for mechanical use and heat transfer. Products used to maintain proper water conditions are often automatically introduced by sophisticated equipment directly into the water in a chiller or boiler. The water is used for both cooling and heating in large commercial building applications. In most industrial settings, water is used to cool production equipment or as an ingredient to make a product. How the water is used will determine what type of treatment is necessary.
Most water treatment companies use test kits and chemical dispensing systems which have made it much easier to use water treatment chemicals in refrigeration systems, boilers and cooling towers. But attention to detail, such as how often systems are tested, is critical to system performance. The right water treatment chemistry at the right time is extraordinarily important because even minor problems can lead to significant costs.
Last week I sat down for breakfast with Gary Reynolds and Bob Schubert of Garratt Callahan. They are ‘specialists’ in water treatment. Gary and I have worked together on several mutual clients. His attention to detail, customer service and vast knowledge of water treatment is why so many buildings in the Mid South are in good hands with Garratt Callahan. At our meeting, I was provided with excellent information on the importance of water treatment, the effects of poor service, and things to consider when choosing a service provider.
2. How does poor or no service affect mechanical equipment?
Improper water treatment or lack of treatment will increase your energy consumption and operating cost while decreasing the efficiency and life expectancy of your mechanical equipment. A well designed and implemented water treatment program is very important to the operation of any steam boiler, centrifugal chiller and cooling tower. The three systems shown below use water for cooling and heating.
Poor water treatment allows water to interact with pipe surfaces and the vessels that contain it. Steam boilers can scale or corrode, and these deposits will mean more fuel is needed to heat the same amount of water. Cooling towers can scale and corrode, but if left untreated, the hot, dirty water they may contain will encourage bacterial growth, and Legionnaires’ disease can be the fatal consequence. Condenser tubes inside a chiller and other water-cooling equipment can also foul and corrode, preventing good heat transfer. Increased energy consumption and poor cooling performance are common results of inefficient water treatment.
Water treatment can often be classified as “low-tech” and unglamorous. However, the right chemicals, the right chemical feed equipment and a dedicated service provider are essential for your mechanical equipment and should be ‘treated’ with the highest priority.
3. Are there energy savings with water treatment?
Treatment Value: Expert water treatment can substantially reduce water, energy, and maintenance costs. Perhaps most important of all, it can save you the cost of repairing or replacing equipment damaged by improper water treatment, including the downtime and lost revenue typically associated with resolving such problems.
The water treatment ROI (return on investment) examples below show how very thin layers of material deposited by poorly treated water can increase energy costs.
Scale
System: 1,000 ton cooler
Operation: 12 hours/day, 365 days/year
Electricity cost: $0.10/kWh
Scale thickness: 1/32 inch
Eliminating 1/32 of an inch of scale saved $15,018 per year.
biological fouling
System: 1,000 ton cooler
Operation: 12 hours/day, 365 days/year
Electricity cost: $0.10/kWh
Biofilm thickness: 1/1000 inch
Removing 1/1000 inch of biofilm saved $26,834 per year.
“A scale as small as 3/16 of an inch can cause a boiler system to use 38 percent more fuel. The tiniest amount of dissolved oxygen in the water also means a system could have corrosion problems. And even A thin layer of bacterial slime on cooling tubes can significantly affect heat transfer efficiency.”
To wrap:
As mechanical contractors, we are no strangers to the importance of water treatment. However, after researching and writing this article I can assure you that I am much more informed about the necessity and benefit of having a good water treatment program.
In this Mechanical Matters® issue, I’ve discussed three important facts about chemical water treatment. We first learned the definition of water treatment and its use in the mechanical industry. Second, we learned that water treatment is definitely necessary, and without it your mechanical equipment will suffer. Lastly, we learned how proper water treatment will save energy and ultimately increase your bottom line.