Why the cooling water system matters
A cooling water system transfers heat away from machinery or air conditioning equipment to the outside environment, with the cooling tower and condenser water system as its key components. If the quality of the circulating water is not appropriate, it will affect the performance of the entire system over the long term.
Commonly encountered problems include:
- Corrosion of steel pipework and heat exchange equipment
- Scale formation inside pipes
- Accumulation of biofilm and microorganisms
- Blockage of the circulating water system
- Reduced heat transfer efficiency
- Higher electricity and maintenance costs
Although many plants use chemicals to control these issues, continuous dosing drives up operating costs and adds environmental wastewater compliance burdens.
What is Ozone Water Treatment?
Ozone Water Treatmentis the application of ozone gas (O₃) to treat the circulating water within a cooling water system. Ozone is a highly effective oxidant, capable of rapidly eliminating bacteria, fungi, algae and biofilm.
The ECONOWATT system generates ozone from oxygen in the air and injects it directly into the circulating water. Once it has done its work, ozone naturally reverts to oxygen, leaving no residual in the system.
Although ozone does not act directly as a corrosion inhibitor, it can effectively help reduce Microbiologically Influenced Corrosion (MIC) — corrosion caused by microorganisms . Because it eliminates the biofilm in which microbial colonies accumulate on metal surfaces.
When the surfaces of pipework and heat exchangers are cleaner, heat transfer becomes more efficient and the likelihood of long-term corrosion is reduced.
Field results
ECONOWATT installed an ozone generation system, model OZG1025N, on Cooling Tower (CT 3-1) at an automotive industry plant in Chonburi province.
The test ran continuously for 190 days (4 November 2025 – 13 May 2026), using corrosion coupons in both carbon steel and copper installed within the circulating water system in accordance with ASTM G4. The results were then used to calculate corrosion rates per ASTM G1 and compared against the criteria of the Association of Water Technologies (AWT).
Water quality during the test
| Item | Test start | Test end |
| Date | 4 Nov 2025 | 13 May 2026 |
| pH | 6.62 | 6.30 |
| Conductivity | 360 µS/cm | 368 µS/cm |
| TDS | 180 mg/L | 183 mg/L |
| Temperature | 30.1°C | 28.7°C |
The data shows that water quality changed only marginally over the test period, demonstrating that the system was able to maintain cooling tower operating conditions continuously under real operating conditions.
Corrosion test results
| Material | Weight loss | Corrosion rate | AWT criterior | Assessment |
| Cabon steel | 0.917 g | 4.0 mpy | ≤ 5.0 mpy | Good |
| Copper | 0.074 g | 0.28 mpy | ≤ 0.35 mpy | Good |
Note:Corrosion rate calculated per ASTM G1 using coupon exposure area according to ASTM G4.
The results show carbon steel corroding at 4.0 mpy and copper at 0.28 mpy. Both values fall below the AWT standard criteria and are classified as “Good”, reflecting the system’s ability to effectively control corrosion of equipment within the cooling water system throughout the test period.
Analysis of the test results and water quality
Beyond the corrosion results falling within a good range, the water quality data offers further insight into the performance of the Ozone Water Treatment system.
Although pH sat in the range of 6.3–6.62 — below 7, a condition that may increase the likelihood of metal corrosion — and although conductivity of only 360–368 µS/cm and TDS of approximately 180–183 mg/L indicate water with a relatively low dissolved solids content, which engineering principles regard as a condition that may also affect metal corrosion, the corrosion rates for both steel and copper nonetheless remained at the Good level under AWT criteria.
This demonstrates that the ozone system effectively controlled the formation of biofilm and microorganisms, a principal cause of Microbiologically Influenced Corrosion (MIC) — keeping equipment surfaces clean and reducing the factors that accelerate corrosion within the system.
That said, to obtain the greatest benefit from Ozone Water Treatment, water quality should be managed in parallel, particularly controlling pH and alkalinity within an appropriate range, in order to reduce corrosion arising from chemical factors and extend equipment service life over the long term.
Benefits of Ozone Water Treatment for cooling water systems
Implementing Ozone Water Treatment in cooling water systems not only controls microbial growth but also enhances the performance of cooling towers and condenser watersystems in several ways:
Reduced chemical use
Ozone eliminates bacteria, fungi, algae and biofilm effectively, reducing reliance on disinfectants and multiple water treatment chemicals. This lowers both chemical procurement costs and the burden of chemical management.
Corrosion control
Although ozone is not a direct corrosion inhibitor, it reduces corrosion indirectly by eliminating biofilm, a principal cause of microbiologically influenced corrosion (MIC) — helping to extend the service life of pipework, pumps and heat exchangers.
Improved heat transfer efficiency
When heat exchanger surfaces are clean and free of biofilm, cooling tower and condenser water systems transfer heat more effectively, reducing the workload on equipment and saving energy over the long term.
Environmentally friendly
Ozone naturally reverts to oxygen, leaving no residual in the water. This reduces the load on wastewater treatment systems and supports business operations aligned with ESG principles and sustainable development.
Ozone Water Treatment: A New Sustainable Alternative for Cooling Water Management
The real-world results of ECONOWATT’s Ozone Water Treatment system at an automotive industry plant over 190 days demonstrate that the technology can control corrosion rates at 4.0 mpy for carbon steel and 0.28 mpy for copper, both at the Good level under AWT criteria. Even while operating under water conditions that would tend to promote corrosion.
Beyond maintaining the performance of the cooling water system, cooling tower and condenser water, the system also reduces chemical use, controls biofilm formation, lowers the maintenance burden, and supports energy saving and sustainable business operation.
For organisations looking to improve cooling water system efficiency while reducing energy costs and environmental impact, ECONOWATT‘s Ozone Water Treatment technology is an option that addresses both the engineering and the long-term management case.
Get in touch
- Line:@econowatt
- Facebook:ไทยเอ็นเนอร์ยี่คอนเซอร์เวชั่น ระบบบำบัดน้ำอนุรักษ์พลังงาน Econowatt
- Tel:02-809-1601
- Email:sales@econowatt.co.th
Frequently asked questions about Condenser Water (FAQs)
Q: How does Ozone Water Treatment reduce corrosion in a cooling water system?
A: Ozone does not act directly as a corrosion inhibitor. It eliminates microorganisms and biofilm, which are a principal cause of microbiologically influenced corrosion (MIC), thereby reducing the factors that accelerate corrosion and helping preserve the surface condition of equipment in the cooling water system.
Q: What types of cooling towers is an Ozone Water Treatment system suitable for?
A: The system can be applied to cooling towers and condenser water systems in industrial plants, office buildings, hotels, hospitals and large buildings. System design should take into account system size, water quality and operating characteristics in order to achieve the best performance.
Q: How does Ozone Water Treatment save energy?
A: When ozone reduces the accumulation of biofilm and fouling on heat exchanger surfaces, the system transfers heat more effectively. Equipment then operates more efficiently, the load on the cooling system is reduced, and energy consumption falls over the long term.