Cooling Towers
— Anti-Microbial Cooling Towers

Anti-Microbial Cooling Towers Reduce Legionella Risk
Anti-Microbial Cooling Towers Reduce Legionella Risk
Anti-Microbial Cooling Towers Reduce Legionella Risk
Anti-Microbial Cooling Towers Reduce Legionella Risk
Anti-Microbial Cooling Towers Reduce Legionella Risk

The Smart Way to Minimize Legionella Risk

Delta’s Anti-Microbial Cooling Towers are designed to minimize the risk of pathogen contamination that leads to infection outbreaks such as Legionnaire’s Disease. The Legionella bacteria thrive in warm water conditions, such as those found in water cooling towers.

Unlike regular cooling towers, Delta’s Anti-Microbial Cooling Towers come with shells made of anti-microbial HDPE resin to inhibit bacterial growth. What’s more, this cooling tower features a unique construction design (steep side-to-side slopes and basin sweeper systems) geared at minimizing the risk of Legionella colonization. Even better, this water cooling tower can withstand strong chemical treatments, which means a much longer lifecycle, reduced costs and downtime.

Introducing our NEW Anti-Microbial Cooling Tower

According to test results from Special Pathogens Laboratory®, The Legionella Experts®, our tower displays the only Anti-Microbial efficacy against Legionella bacteria out of all the common cooling tower materials.

Tower shell

  • Anti-Microbial HDPE Resin
  • Fully Compounded Throughout Resin
  • Resists Biofilm Growth
  • Withstands Most Aggressive Chemical Treatments

Tower Fill & Drift Eliminator

  • Anti-Microbial Compounded PVC or PP
  • Impedes Microorganism Growth
  • Prevents Fouling Maximizing Performance
  • Resists Biofilm Growth

What is Legionnaires' Disease

A harmful lung infection caused by the bacteria Legionella. This bacteria grows best in warm water conditions where it is spread to humans when water vapor or mist containing the bacteria is inhaled. Cooling towers have an ideal environment for this growth.  Although the public concern about Legionnaire’s Disease was paramount during the outbreaks of the mid-1970s, there have been many recent occurrences since then, including over a dozen cases in the U.S., as well as several in Europe and Australia.  According to the CDC, in many of these cases Legionella is incubated and spread through water systems, including the cooling towers that are essential items in commercial building HVAC systems and industrial process cooling.

Growth Promotion

  • Poor water flow and areas where water is stagnant, common to cooling tower designs with a large flat bottom basin, which will have stagnant water in the corners.
  • pH between 5.0 and 8.5, water temperatures between 68°F and 122°
  • Sediment that promote growth of commensal microflora
  • Microorganisms including algae, flavobacteria, and Pseudomonas, which supply essential nutrients for Legionella growth or harbor the organism


  • Chemical Water Treatment: Oxidizing Biocides are recommended as the best mode of control. Warning: this type of biocide can be aggressive towards metal surfaces; specifically metal cooling towers.
  • System Design & Engineering: No stagnant water, sloped basin, and/or basin sweeper system.
  • Maintenance – Competent consistent water treatment and monitoring most important.
  • According to the Center for Disease Control and Prevention, about 5,000 cases of Legionnaire’s disease are now reported each year in the United States.

Delta Anti-Microbial Cooling Tower

We begin manufacturing with anti-microbial resin, which is fully compounded into base cooling tower plastic material. Our anti-microbial additives operate on the cellular level to continuously disrupt and prevent uncontrolled growth of the microorganisms and biofilm.

The blue colored cooling towers are a clear sign to the industry that they are anti-microbial; therefore substantially reducing the risk of harmful cooling tower-borne pathogens, such as Legionnaires' Disease.

Test Results

The bacteria tested were Legionella Pneumophila Serogroup 1. The base materials tested were Delta Compounded HDPE, FRP, and Stainless Steel and the numbers reflect bacterial count after 24 hour incubation.

Testing Agency: Special Pathogens Laboratory, The Legionella Experts®, in Pittsburgh, PA.

Cooling Tower ShellAnti-Microbial Efficacy
Delta AM HDPE Yes
Stainless Steel No
Cooling Tower FillAnti-Microbial Efficacy
Anti-Microbial Fill Yes
Standard Fill No

Tower Design Minimizes Legionella Risk

  • Aggressive Slope Side to Side
  • 3% Slope Back to Outlet
  • Basin Sweeper System on Some Models

Stagnant Water is a breeding ground for microorganisms which reproduces Legionella. Our design prevents stagnant water.

The Most Durable Corrosion-Proof Cooling Towers Available
corrosion proof cooling towers

Corrosion Proof & Seamless Cooling

Delta Cooling Towers contain one piece, shell or casing, eliminating issues with seams, welds, and patches. Because they are rust and corrosion proof, Delta’s Cooling Tower Systems endure longer lifecycles.

Cooling Towers Manufacturer Warranty

Low Maintenance
and 20-Year Warranty

Our overall maintenance is minimal and the tower shell does not require preventive maintenance which lowers cost and expensive downtime. The benefits are extraordinary!

water cooling sustainability


Water chemistries and engineered plastic cooling towers combined translate into an extremely effective solution to water conservation as well as cost savings.

quiet cooling tower systems

Low Sound &
Other Special Options

The noise pollution of commercial HVAC equipment has become an increasingly unwanted problem for communities. Delta Cooling Towers are unrivaled among other manufacturers in providing solutions.

USA and international company

Made in

The term “Made in the USA” speaks of quality, excellent craftsmanship, and a superior product. Delta ranks as the technology leader among cooling towers manufacturers in USA!

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From our low maintenance design to our manufacturing process to excellent customer service, we're sure you'll be pleased with our superior cooling towers, every step of the way. Get a quote