Real Estate

HVAC – Is Water Treatment Necessary?

Drummers, soap sellers … they have been called by many names. Water treatment specialists (probably the name they prefer) are everywhere. As a mechanical contractor, we have had many knocks on our door. With most large commercial buildings and industrial facilities in Memphis using mechanical water heating / cooling equipment, this industry is highly 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 issue I want to answer three questions about water treatment:

What exactly is water treatment and is it necessary?

How does improper water treatment service affect mechanical equipment?

Is energy saved with water treatment?

1. What exactly is water treatment? 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 mechanical and industrial water-based processes, such as: heating, cooling, processing, cleaning and rinsing, thereby reducing costs and operational risks.

Most water treatment programs include water softeners, inhibitors, and other chemicals necessary to “treat” the water to achieve the desired conditions for mechanical use and heat transfer. Products used to maintain proper water conditions are often automatically fed by sophisticated equipment directly into the water from a chiller or boiler. 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 chiller, boiler and cooling tower systems. But attention to detail, like how often systems are tested, is critical to system performance. The right water treatment chemistry at the right time is extremely important because even minor problems can lead to higher costs.

Last week I sat down for breakfast with Gary Reynolds and Bob Schubert from Garratt Callahan. They are “specialists” in water treatment. Gary and I have worked together with several mutual clients. His attention to detail, customer service, and vast knowledge of water treatment is why many buildings in the Mid-South are in good hands with Garratt Callahan. At our meeting, I was given excellent information on the importance of water treatment, the effects of poor service, and the things to look for when choosing a service provider.

2. How does poor or no service affect mechanical equipment?

Improper water treatment or no treatment at all will increase your energy consumption and operating costs while reducing 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 the surfaces of pipes and containers that contain it. Steam boilers can scale or corrode, and these deposits will mean that more fuel is needed to heat the same amount of water. Cooling towers can scale and corrode, but if left untreated, the warm, dirty water they may contain will encourage the growth of bacteria, and Legionnaires’ disease can be the fatal consequence. Condenser tubes inside a chiller and other water cooling equipment can also scale and corrode, thus preventing good heat transfer. Higher power consumption and poor cooling performance is a common result of ineffective 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 must be “treated” with the highest priority.

3. Is energy saved with water treatment?

Treatment Value – Expert water treatment can substantially reduce your 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 that are usually associated with troubleshooting such problems.

The ROI (return on investment) examples of water treatment shown below show how very thin layers of material deposited from 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

Removing 1/32 inch 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 of an inch of biofilm saved $ 26,834 per year.

“As little as 3/16 of an inch of scale can make a boiler system 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 film of bacterial sludge on chiller tubes can significantly affect heat transfer efficiency. “

Wrap:

As mechanical contractors, we are no stranger 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 need and benefit of having a good water treatment program.

In this Mechanical Matters® issue, I 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.

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