Oil refinery plant at twilight dark blue sky

A typical industrial or institutional cooling water system is arranged like the schematic in Figure 1. There are typically two water loops and a refrigerant loop. Chilled water is circulated in the chilled water loop through the apparatus or building that needs cooling. Heated water is returned  through an evaporator where refrigerant is evaporated by the heat from the warmer chilled water. This refrigerant is compressed and condensed by cooler water returning from a cooling tower in a tower water loop. Solution 3000 can solve serious problems caused by microorganisms in both loops of the system through which water circulates.


Among the problems that chlorine dioxide can solve are

  • buildup of odors and, slime, caused by an increased microorganism population,
  • loss of heat transfer in the condenser and evaporator, due to biofilm in the water side of heat exchangers.
  • increased corrosion rates, due to
    • electrochemical cell formation in the biofilm
    • proliferation of sulfur reducing bacteria (SRBs) and Iron reducing bacteria (IRBs) and
    • blocking of the contact of any corrosion inhibitor with the metal,
  • increased pumping energy required to circulate the cooling water in the presence of a bio film which can obstruct pipes and has a high friction factor.

In addition, biofilm growing in a tower water loop may also contain Legionella, which can be aerosolized and infect people up to a mile or more from the tower. Therefore, control of microorganism buildup is essential for safe, efficient operation of both water loops in a cooling water system. Chlorine dioxide is often the most effective and economical way to achieve this.

Water Tower Graph

Chilled water loops and tower water loops have very different biocidal needs; Every cooling system is different. For help with Chlorine dioxide use in cooling systems contact us: