5 0 A S H R A E J o u r n a l a s h r a e . o r g J u l y 2 0 0 7 Bill Gaines is a principal engineer with Ford Motor Company in Dearborn, Mich. Martin R. Orban is a director of product management & technology at Mitco in Grand Rapids, Mich. David R. Welch is the Michigan district manager at Mitco.
About the Authors By Bill Gaines, Martin R. Orban, and David R. Welch
15
Things to Know
About Cooling
Water Treatment
A
n objective evaluation of competing cooling water proposals
only can be made when they are uniform. An unambiguous
specifi cation would seem ideal for this purpose. Yet each facility
is unique and industry standards of quality and performance still
leave open areas of interpretation due to those unique system
characteristics. How can a facility manager know when a change
in suppliers or chemical program is warranted?
of course, be economical and provide value to the customer. A cooling water treatment program must have the same qualities. Poorly specifying performance metrics is unwise and imprudent, yet writing entirely prescriptive requirements for a cooling water program is, at best, diffi cult and impermanent. Constantly changing regulations, variable manufac-turing fl uids/processes, and development of new treatment chemistries demand
that a treatment program be fl exible to refl ect optimum conditions. A compre-hensive system specifi cation that rules out discovery, experience, and innova-tion minimizes the opportunity to use a supplier’s expertise. It also sets the stage to focus on the specifi cation rather than actual system performance.
Does this mean a well-defi ned per-formance specifi cation isn’t necessary? Indeed not! The need for an explicit specification is critical to protect the integrity of process equipment. The indi-vidual elements of what must be included have been well documented in previous literature.1,2 Unfortunately, industry
standards of quality and performance still leave areas open to interpretation due to unique system requirements, and create signifi cant variations between apparently similar proposals. Given this situation, This article provides a practical guide
to determine the value of a water treat-ment program and to perform a critical re-view of alternative programs. It is equally suitable when proposals are solicited or when an end-user wants to compare a new supplier to an existing program.
In the auto industry, a “tight” part spec-ifi cation is a necessity. Components must meet rigid tolerances, be of high qual-ity, perform to expected standards, and,
5 0 A S H R A E J o u r n a l a s h r a e . o r g J u l y 2 0 0 7
The following article was published in ASHRAE Journal, July 2007. ©Copyright 2007 American Society
of Heating, Refrigerating and Air-Conditioning Engineers, Inc. It is presented for educational purposes
only. This article may not be copied and/or distributed electronically or in paper form without permission
of ASHRAE.
how can a facility manager know when a change in suppliers or chemical program is warranted?
Five Front-End Elements to Establish
There is no single “right” solution to selecting a treatment regime. Even the “best” program involves tradeoffs between cost and effectiveness. However, certain elements always im-prove the likelihood of success:
1. System Characterization
Nothing is more important than an accurate system character-ization -- it is the foundation upon which all other decisions are made, and provides the basis for proposals that optimize cost and performance. Even greater benefi t is gained when suppliers are offered the opportunity to survey the system to gain ad-ditional information. Essential system characteristics include: The volume of water used in the previous year (if unknown, start measuring it);
The number of operating days and seasonal variation; The total system volume (easy to determine);
A complete makeup water analysis (if you don’t have one, get one);
The recirculation rate (if unknown, pump horsepower or tons of cooling capacity can be used to estimate it until it is measured);
Present cycles of concentration (CoC); and
A list of the materials of construction for all wetted parts within the system.
Water usage is a source of diffi culty in bid preparation and evaluation. Left to their own, suppliers who may have to estimate makeup and blowdown will skew cost estimates. In the absence of reliable metered water usage, it is essential that annual water usage be defi ned in the specifi cations.
2. Restrictions
Any restrictions due to discharge requirements or corporate policies must be communicated (e.g., zinc and/or molybdate not allowed). Equally important is when there is a bias toward a particular program (e.g., halogen). In this case, the active chemi-cal and its control range must be defi ned, while still allowing voluntary alternate programs that use supplier experience.
3. Performance Metrics
The current metrics (if satisfactory) or expectations (if unsat-isfactory) must be communicated. Remember that high demands escalate costs and may promote future dissatisfaction. The best method for determining performance metrics is to combine in-formation garnered during the bidding process with knowledge from the vendor, end-user and industry organizations.
High performance cannot be sustained without proper train-ing. Vendors need to provide a manual to administer the program safely and as designed. Such a manual needs to include at a minimum:
Emergency contact information;
Chemical treatment programs and control limits;
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Test procedures, interpretation of results, and corrective actions;
Product bulletins and material safety data sheets (MSDSs); and
Routine service reports.
4. “Face Time”
Treatment programs are provided on either a full service or limited (namely, advisory) basis. Under a full-service agree-ment, the supplier provides total management of the program. Under a limited agreement, the supplier recommends a program, provides chemicals and offers consulting to the site. Facility per-sonnel maintain the equipment, administer the chemicals, and monitor water quality, operational characteristics, and program performance. The primary responsibility of a water treatment supplier is to manage the water treatment program. The supplier should ensure the completeness of analytical tests, know how to interpret them and foresee potential problem areas.
“Face time” is the frequency and duration of “service” pro-vided by the supplier. In many cases, this is the most costly of all the program components. Therefore, interview the rep-resentative as if you were hiring a full-time employee. Real-ize that when you specify service frequency, you are directly impacting the program cost and inviting a cost that may not connect to your desired program value. The experience of the representative plays a critical role in program success and cost. Although dollars spent divided by hours of service may be a helpful calculation, it is the quality of service that determines the largest portion of program value.
Alternatively, one must ask “What are the components of the present service program? What actually happened in the hour of service that I received and how much am I willing to do in support of the program that I specify?” Many high-performing programs are 90% self-managed.
5. Deliverables
Operator logs and vendor service reports provide valuable data that in conjunction with water, deposit, and other analyses, measure progress against defi ned performance metrics. Regular reviews of the program cover performance, costs, problem areas and corrective action plans. Therefore, it is common to request a copy of a review authored by the representative you are con-sidering. Also, a water treatment company’s corporate support structure impacts its pricing. Be aware of the type and amount of additional support that you most likely will need.
Five Elements to Establish During the Selection Process
Uniformity among the various proposals is crucial to allow objective evaluation. Seeking an apples-to-apples comparison works well for apples, but not always for water treatment pro-grams. Each facility is unique and industry standards of quality and performance still leave many areas open to interpretation based upon those unique system characteristics. Once propos-als are received, the process of evaluating them can be quite challenging. Five areas requiring evaluation are:
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5 2 A S H R A E J o u r n a l a s h r a e . o r g J u l y 2 0 0 7
1. Product Evaluation
MSDSs don’t provide suffi cient information to compare products. End-users usually address this is by requiring full disclosure with submittals. Full disclosure allows the end-user to examine programs in terms of suitability, health and safety, and material compatibility. Once the proposals and product information are in hand, one can compare them to the previ-ous years’ total pounds of each chemical used, cost per pound, total program cost, and the number of hours that the supplier spent on site. One must consider the product recommendation and its impact on CoC. The product concentration (dilution) accounts for wide variations in unit pricing, making it impos-sible to compare usage and cost. Therefore, respondents must also provide annual use rates. Maximum cycles also vary depending on the treatment chemistry. Similar programs from different vendors ought to yield similar CoC. If a program has greater cost but higher CoC, then the evaluation should refl ect the reduced makeup. An insightful metric is total annual cost divided by million pounds of blowdown.
Ideally, deviations are addressed during the pre-bid meeting and walk-through. But if a reasonable irregularity surfaces after the fact, then bidders need to be offered an opportunity to make appropriate revisions. However, they should not be allowed license for changes outside the irregularity identifi ed.
2. Method of Application
Just as the choice of chemistry must be appropriate to the individual system, so too must be the method of addition. Pro-posals must address:
a. Control Method: Is the feed and monitoring equipment ap-propriate for the chemical program? Will it be on a continuous or intermittent basis, or a combination of both? If additional equipment is required, several options are available:
Direct Purchase: End-user purchases and installs required equipment;
Lease-to-Own: A third-party lease agreement;
Added to Price of Chemical: This is popular when capital budgets are limited. However, both parties must understand the term and/or volume limits for which the adder is ap-plied (a depreciation schedule is advantageous if there is a need to change vendors before satisfying the terms of the agreement); and
Vendor Supplied: The vendor retains ownership and mainte-nance and folds the cost into the chemical price. This method is gaining in popularity as more end-users view this as an op-portunity to keep up with advances in control technology. b. Inventory Management: Proposals must be consistent with the end-user inventory needs and storage of each product appro-priate for its usage. They must also demonstrate that adequate
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but not excessive inventory levels will be provided. Many companies do not want to dispose of containers when drums are used, and some vendors have responded with “drumless” programs.
c. Ordering/Shipping: While most end-users specify FOB delivered, this is often not the most economical choice. Overall charges are cheaper when higher volumes
are shipped, but some vendors apply a higher freight charge in case only a few drums are ordered. Usually it’s better to specify prepay and add. This way, the end-user enjoys the quantity freight dis-counts for large orders, as well as, lower charges when only a few containers are shipped. Alternatively, it’s often advanta-geous to ship on a consignment basis if
the end-user has storage space and the parties agree on invoicing methods. The vendor minimizes cost by shipping larger truckloads less frequently and passes the savings on to the end-user.
3. Who Do You (And Who Do You Not) See?
Proposals must identify resources that will be made available when the primary representative is unavailable. They must include names and biographical informa-tion for the primary and backup support personnel, as well as, the key corporate support personnel to be assigned under such conditions. Thoroughly check all references!
Evaluation of services cannot be made by a predetermined formula that applies to all cases. However, certain questions aid in the review:
Does the service representative have the skill to identify and correct prob-lem areas as they arise?
Does the proposal consider plant procedures, safety training and lock-out procedures?
What is supplier turnover rate, and how long have the personnel been assigned to the local area?
Is there an allowance for emergency service? If so, are separate charges clearly delineated?
Is periodic (typically annual) in-depth equipment inspection provid-ed? Proposals should describe how this will be done and what inspection equipment is to be used.
4. Corrective Measures for Routine ‘Out of Control’ Parameters
Given the highly dynamic nature of plant systems, an unexpected event will occur. When the program is collaborative, service is proactive, and standard operating proce-dures have been written; then personnel fol-low uniform methods to “act and correct” following an upset. The answer to a water treatment problem is not always the applica-tion or increased usage of a chemical. The representative must always be cognizant of physical or operational changes, as well as, chemical upsets. It has been reasonably stated that “…80% of chemical problems are mechanical.” Above all we must try to
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remember that, in the real world, change is sometimes necessary. When this occurs, the method of change should be thoroughly considered, rather than a knee-jerk reaction. The management of change is best achieved when a systematic approach is applied to each process and subprocess.
5. Non-routine Service
If one accepts the premise “anything that can fail will ultimately fail,” then it follows that a well-designed program must allow for unforeseen and unscheduled equipment outages. It is in the best interest of both parties that non-routine service be addressed upfront. Although there is no single correct formula for defi ning this, the most common method resembles the following: Basic contract allows for x hours of routine service plus y hours of non-routine/emergency service in conjunction with z hours of analytical laboratory work for a contracted price. Work required beyond these allowances to be charged at a predefi ned hourly rate.
Five Ongoing Elements
Once a program is established and underway, there are ongo-ing aspects that require continuongo-ing evaluation:
1. Meeting Performance Metrics
The most fundamental measure of supplier performance is that all metrics and deliverables identifi ed in the front-end ele-ments are being met. Proof that tests were performed at their scheduled frequency, all parameters were within prescribed control limits, and performance objectives were achieved, must be clearly documented.
2. Risk Management
A risk management program (that should have been jointly developed) includes a hazard analysis and risk assessment. Each portion needs to be reviewed annually to ensure it remains cur-rent for changes made during the previous year.
The hazard analysis is intended to identify safety and envi-ronmental hazards by rating their severity and likelihood of oc-currence, and then establishing controls to reduce or eliminate them. It is fundamental to evaluate and improve the safety of cooling water systems. A process fl ow diagram needs to indi-cate where spill prevention is required and where personnel exposure potential exists. Sensible control for strategies for hazards must be included. A Legionella-specifi c system assess-ment must review all water systems for their aerosol potential, temperature, physical condition, cleanliness, and location.3
Risk assessment data should include: makeup and system water analyses, system design, operating characteristics, and potential for equipment fouling due to scale and bioslime.
3. Exhibiting Innovation and Foreseeing Problems
The subjective aspect of supplier evaluation is the most diffi cult. However, one can examine a supplier’s ability to continually demonstrate eagerness and innovation. When the representative is engaged in the treatment program, he’s not concerned solely with routine testing, but rather strives to
improve results and reduce costs. He “crawls upstream” to discover manufacturing fl uid and process changes, and then reacts ahead of time. He becomes involved in water treatment issues and checks performance of equipment outside the scope of his services. The representative must recognize downsides to proposed changes. For example, reducing circulating pumps to save energy may decrease fl ow velocities and turn heat exchang-ers into sedimentation tanks. Isolating (no fl ow) loops for energy savings may promote corrosion and uncontrolled microbiologi-cal growth. Cycling standby equipment at greater than one week frequencies may allow proliferation of bacteria to inoculate the system upon startup. It takes an experienced water-treater to know when these types of changes are prudent.
Methods have been developed that quantify the subjective por-tion of the evaluapor-tion. Most of these involve a matrix consisting of a comprehensive list of qualities in the fi rst column, a weighting factor determined by the end-user in the second, and a force-ranked rating in the third. Multiplying each score by its weighting factor and totaling all scores produces a single fi nal score.4
4. The Happiness Factor
The most diffi cult portion of supplier evaluation to examine is the “happiness” factor. How much of my present satisfaction with the program is unrelated to system performance or cost?
If there is a component of satisfaction that is not covered in the specifi cation, then examine whether or not that criteria is appropriate. For instance, some managers want all information immediately communicated and want to be involved in every decision (high supplier visibility); while others value quarterly reviews and exception reporting, knowing the supplier is manag-ing the details of the program (supplier invisibility). An ongomanag-ing program evaluation process helps to reduce the reliance on the “happiness factor” for supplier retention or change.
5. Knowing When a Cost Increase is Justifi ed
Owners are often approached for a cost increase due to a “changed condition” from the specifi cation. The question is whether or not the so-called “changed” condition should have been foreseen during the bidding process. Manufacturing fl uids and processes are constantly changing, so sometimes a cost increase is justifi ed. Other times, it is an unjustifi ed ploy by the supplier to in-crease sales or unnecessarily push one up the technology scale.
Equipment and chemicals are closely interrelated. A sticking solenoid valve can cause chemical use to dramatically increase— which is not a water treatment problem but rather a maintenance issue. New production equipment, accidental contamination of the cooling water (for example, by hydraulic oil), and new discharge restrictions are examples of changes that the supplier would not have foreseen (and for which they must be compensated).
However, many common occurrences ought to have been antici-pated and are not to be compensated. These include: 1) Sediment buildup from wind-blown dirt into a cooling tower causing ad-ditional biocide usage; 2) A makeup fl oat that became stuck open but was repaired in a timely manner; and 3) Legionella entering a cooling tower requiring immediate disinfection.
Conclusions
No single “correct” method exists for selecting and manag-ing a coolmanag-ing water program. High-performance programs can range anywhere from nearly 100% vendor-managed to almost completely self-managed. Under any condition, however, it is a well-defi ned set of performance metrics, a disciplined data acquisition and analysis approach, and a mutual sense of ownership that drives success. Knowledge and application of several key elements during the front-end development, selec-tion process, and ongoing periods can ensure a solid platform for balance of cost and performance.
References
1. Chesney, W.W. 1996. “Preparation of bidding specifi cations for chemical services relating to cooling water and boiler treatments in industrial facilities.” 57th International Water Conference, p.333.
2. Simon, D.E. 1997. “Comprehensive specifi cations for contracted water treatment service programs.” 58th Annual International Water
Conference, p.172.
3. Turvey, T., Kuchinski, J. 2006. IWC-06-01 “The Legionella shift: how the risk from Legionnaires’ disease has changed the perception of water treatment.” 67th Annual International Water Conference.
4. Howard, K., Winters, M. 2002. “A performance-driven approach to cooling water treatment evaluation.” 63rd International Water
Conference, p. 629–635.
