The HVAC Factor: Water Treatment Services
By Jay Farmerie, CWT
Originally published in the August 2010 issue of Today’s Facility Manager
To limit the use of energy, it is important to have a good water treatment program in order to keep these systems free of scale, deposits, corrosion, and microbiological growth. Scale and deposits decrease heat transfer efficiency which increases use of natural gas, fuel oil, or electricity. Corrosion can cause equipment to operate inefficiently, and microbiological growth can cause disease and fouling.
Another aspect of water treatment is a focus on limiting the use of water. This could include running higher cycles or recovering and reusing possible waste streams which will ultimately save the facility money.
Selecting a water treatment supplier can be accomplished in several ways, including request for proposals (RFPs); request for quotes (RFQs); bid submittals; personal interviews; and even personal relationships. No matter which one of these methods an fm uses, it is necessary to develop criteria for deciding what kind of service is needed to protect the facility’s cooling equipment from failure or unexpected shutdowns that can cause disruption to occupants, as well as lost revenue.
Fms should first decide what type of service their facility requires. There are basically three levels of service:
1) The first level is a service program designed to ensure proper application of the water treatment program. In this scenario, the water treatment company provides a product and instructs the facility on how to operate within the specified limits of the system. In this case, the water treatment provider is a chemical supplier rather than a full-service provider. This level of service is the least expensive, but it is not a good option if the facility does not have:
- full-time experienced operators who cover all shifts, understand water treatment, and need no training;
- a full-time engineering staff that can work on water related problems; or
- a water consultant on retainer to provide help when needed.
2) The second level of service is one designed not only to provide treatment products, but also to ensure adequate protection against corrosion, deposition, and microbiological growth. This level of service (the standard for a full-service supplier) requires the service representative to monitor the system performance by periodic checks, including water testing, corrosion coupons, microbiological testing, and deposition analysis.
Water testing should include all the characteristics to determine the standard scaling indices, inhibitor levels, and corrosion byproducts for the system metallurgy. Microbiological testing can include bacterial dip-slides, adenosine tri-phosphate (ATP), and anaerobic bacteria testing. Corrosion coupon analyses should be done continually with either coupons or by linear polarization. Deposition analysis is done to understand any deposits and the causes of their formation.
In addition, pretreatment systems, where no chemical treatment is used, yet which can impact the performance of heat exchange equipment, also need to be monitored by the water treatment professional. Examples of this type of equipment are water softeners, demineralizers, reverse osmosis (RO), electrodeionization (EDI), and make-up water.
In addition, systems in which no treatment is used are also monitored if they have an impact on the performance of the downstream equipment (softeners, demineralizers, RO, etc.). Such a basic program may include assistance in solving minor problems, but it frequently does not if the service provider is inexperienced.
3) A third level of service consists of the components listed in the two categories above, while also including the initiation of projects to optimize system performance and reduce energy or utility costs, reduce water or sewage costs, increase water reuse, or decrease chemical usage.
Such a program is the highest level of service and attention, which can only be supplied by an experienced water treatment professional with full commitment and support from his or her corporate technical staff and laboratories. This can be referred to as a provider who provides value added service.
This decision is important because, as demonstrated in the chart, the biggest factor in controlling costs is not chemical consumption, but utilities usage.
Setting Qualification Criteria
Once fms have identified the appropriate type of service required, they can set qualification criteria for a potential water treatment company.
Questions to consider include: Can they provide the service needed in a timely manner? Will they provide electronic and written service reports on an agreed upon frequency? Can they maintain proper inventory of products? Are they able to provide 24 hour response? Will they proactively work with the fm as a partner and be concerned about the performance of all systems? Do they have the knowledge to reduce the facility’s carbon footprint? Can they provide information on projects and related return on investment (ROI) figures to enable the facility to save money?
The company that is selected must also support their water treatment professionals with the latest information including feed and treatment equipment, testing techniques, regulatory information, and backup technical personnel, if necessary.
Selecting a water treatment company is also about selecting the professional who will be responsible for the treatment program. When reviewing an individual, fms should consider factors such as education, experience, integrity, and personality.
The education level can be measured in several ways. Is the professional’s education in the area of intended use? Knowledge about the types of systems that they will be dealing with is imperative. Has the individual received continuing education through their company or other training that has provided them with an understanding of the operation, maintenance, and treatment of water based systems? Do they understand the concepts of external treatment, corrosion and deposition control, biological control, system performance management, data trending, feed and control systems, safety and regulatory matters, and budgetary issues?
The experience level of an individual is not just the number of years a person has been in the business. Fms should consider the following.
- Do they have experience with various systems, especially the ones for which they will be responsible?
- Do they understand the key performance indicators (KPIs)?
- Can they identify areas that need immediate attention to prevent equipment damage, eliminate a possible environmental incident, or avoid a potentially unsafe condition?
- Have they helped other facilities reduce their carbon footprint or utility usage?
Developing Performance Checks
Once an fm has considered the qualifications of a water treatment company and its professionals, the final step in the process is to develop precise performance checks that will allow an understanding of how the systems are working. This type of criteria is often developed with the help of members of the facility’s engineering staff who have specific knowledge about the systems. They should know which pieces of equipment are critical to the facility’s operation. These would include heat exchangers, condensers, boilers, and cooling towers, etc.
The water treatment professional should help the client facility develop the criteria to understand characteristics of the equipment such as temperature differentials or flows that need to be maintained, boiler efficiency, maximum stack temperatures, scaling or fouling factors at which the equipment can still operate effectively, mass balance data to understand how a system is operating, and system materials/metallurgy and maximum tolerable corrosion rates for each.
One of the most important system checks is to define bacterial growth limitations in order to limit fouling and prevent the cooling water systems from becoming a disease source.
The Big Picture
The task of selecting the right water treatment service provider should not be taken lightly. Selecting the right partner can improve the facility’s operational performance and control the operating budget for items such as electricity, gas, water, and sewage. Moreover, developing a relationship with the service provider will allow for proper protection of the cooling equipment from failure or unexpected shutdowns. This ensures that daily operations continue and allows fms to meet their organization’s sustainability and budgetary demands.
Farmerie has been in the water treatment field for more than 20 years. He is a past president of the Association of Water Technologies (AWT) and is a senior consultant for Cyrus Rice Water Consultants, an independent water treatment consulting and engineering firm in Pittsburgh, PA. AWT (www.awt.org) is an international trade association representing more than 500 companies that specialize in industrial and commercial water treatment for heating and cooling systems.
What services do you expect from your water treatment provider? What has been your experience with providers you have hired? Send your thoughts to [email protected].
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