Cooling towers are typically in the back of a facility’s mind until something goes wrong. So, it’s common when our customers are unsure what operating their cooling tower’s water treatment system should cost. Vendors offer water treatment programs that vary in price and size, which makes it challenging to know which is best for your cooling tower. EAI Water is here to explain how the criteria to use when considering a new cooling tower water treatment program and how to compare programs side by side.

Three Considerations

Three factors determine the operational cost of your cooling tower’s water treatment program.

1. Scale and Corrosion Inhibitors – This 2-in-1 package reduces scaling and corrosion on heat exchange media to maintain your cooling tower’s heat transfer efficiency and life span.
2. Oxidizing Biocides – These are typically chlorine or bromine-based chemicals that abate biofilm and other biological impurities. Recently, the costs for these chemicals have surpassed scale and corrosion chemical costs. 
3. Non-Oxidizing Biocides – Similar to oxidizing biocides, these products inhibit biological growth in your cooling tower.

It’s good to understand your total water treatment cost but looking at the cost per volume gives better insight. EAI Water recommends analyzing treatment costs per 1,000 gallons of makeup water. This method demystifies your operational costs when demand varies and sets an apples-to-apples comparison among competing vendors during procurement.

So What Should Cooling Tower Water Treatment Cost?

From our research and industry experience, as of 2023, operating your water treatment system should cost between $2.50 to $3 per 1,000 gallons of makeup water. $3 to $4 per 1,000 gallons is reasonable, but your staff should investigate which of the Three Considerations to optimize. Any costs beyond $4 per 1,000 gallons or, inversely, below $2.5 per 1,000 gallons indicate a poorly performing program that is over- or under-treating your system in most cases. Reducing your chemical use will have immediate savings, while increasing your chemical use will help avoid costly maintenance related to an undertreated system.

How to Save on Operations

Along with the Three Considerations, here’s where to adjust your water treatment program to bring your facility savings today.

1. Onsite Biocide Generation – As mentioned, biocides are now a cooling tower treatment system’s highest operational cost. We suggest onsite chlorine or bromine generation to stabilize this expense and shield your facility from the disrupted supply chain. Many vendors sell bleach generation equipment that only requires salt, electricity, and water. Relying on table salt instead of a bleach supplier may give your budget predictability and long-term savings.
2. Cycles of Concentration – EAI Water finds that reducing “bleeding” or “blowdown” gives the most dependable savings for a treatment program’s operations. Ask your supplier how many cycles of concentration your system is rated for and see if there are operational tweaks that could save your facility money.

Performance

Facilities consider operations and capital costs when buying a new cooling tower treatment equipment or changing a treatment program. But viewing these costs through a lens of performance is vital to long-term satisfaction. It can be tempting to pick the cheapest vendor, but a well-performing program will prevent endless headaches after installation. Here are performance factors to consider when assessing your current program’s performance and considering a change:

1. Cycles of Concentration – The number of cycles of concentration your system can handle before bleeding or blowing down is critical to operational performance and cost. Your treatment system’s ability to run above five cycles of concentration will lower the system’s operating costs significantly.
2. Corrosion rates – Ask vendors if they can deliver the industry standard corrosion rate of <2 mils/year. Higher corrosion rates negatively impact your cooling tower’s lifecycle. While meeting industry standards are important, you should also be cautious about overfeeding corrosion inhibitor chemicals to the point of exceeding standards. This will drive up operating cost, but will not necessarily extend the life of your cooling tower in a meaningful way.
3. Bacteria Counts – Evaporative cooling systems breed bacteria and biofilm that foul your cooling tower. And removing fouling is costly. Be sure the vendor can promise the level of sanitation your system needs. If their system allows biofilms to emerge, you’ll pay for it in maintenance and inefficient heat transfer.
4. Service Support – Consider how much your team values technical support and reliability, then ask vendors about their local service support. Having a nearby Certified Water Technologist (CWT) is the dependability you need when things go awry.
5. Familiarity – Be sure the vendor knows your region. Cooling tower operations depend heavily on climate. It’s a safer bet to buy from a company that understands your area and has similar clientele. The last thing you want is a treatment system designed for Nebraska’s climate when your facility is in Mesa, AZ.

Selecting and executing an effective and cost-conscious cooling tower’s water treatment program doesn’t have to be complicated. We hope this article breaks it down in a way that’ll make your next bid more manageable. EAI Water understands these systems’ challenges and develops new technologies that will change the variables discussed in this article. Whether you want to focus on optimizing your current program or look into the future, reach out to learn more.