As global demand for cloud computing and artificial intelligence grows, data centers are expanding rapidly. While much attention is paid to their energy consumption, water use is becoming an equally critical sustainability issue.
Cooling infrastructure—especially evaporative cooling towers—can consume large volumes of water. Innovative treatment solutions such as ozonation now enable data centers to reuse water, reduce chemical use, and significantly lower their environmental footprint.
This article explains how ozonation helps improve water efficiency and sustainability in modern data centers.
Why do Data Centers use so much water?
Water consumption mainly comes from cooling systems, particularly evaporative cooling towers used to remove heat generated by servers.
Water is lost through:
- Evaporation during cooling,
- Blowdown (purging) to control mineral concentration,
- Maintenance and cleaning operations.
A large data center can consume tens or even hundreds of thousands of cubic meters of water per year, sometimes equivalent to the usage of small towns.
Water efficiency is therefore becoming a major sustainability KPI, often measured by Water Usage Effectiveness (WUE).
The role of ozonation in Data Center water treatment
Ozonation involves injecting ozone (O₃) into water circuits. Ozone is a powerful oxidizing agent that:
- Eliminates bacteria and pathogens (including Legionella),
- Breaks down organic contaminants,
- Reduces biofilm formation,
- Limits algae growth,
- Leaves no chemical residue, reverting back to oxygen.
This makes it particularly suitable for cooling water systems.
How ozonation enables water reuse
1. Reduced blowdown volumes
In conventional cooling systems, water must be frequently purged to prevent mineral and biological buildup.
By improving water quality, ozonation allows:
- Higher cycles of concentration,
- Less frequent purging,
- Reduced fresh water intake.
Water savings of 20–50% are commonly achievable.
2. Reuse of purge water
With additional filtration, ozonated purge water can often be reused for:
- Cooling tower make-up,
- Technical cleaning,
- Landscape irrigation,
- Non-potable facility uses.
This reduces both consumption and wastewater discharge.
3. Improved heat exchange efficiency
Biofilm and scaling reduce heat transfer efficiency. Ozone limits their formation, leading to:
- Better cooling performance,
- Reduced maintenance,
- Lower operational losses.
Economic benefits for Data Centers
Ozonation systems typically generate savings in several areas:
Lower water costs
Reduced make-up water demand and wastewater discharge fees.
Reduced chemical use
Partial or total reduction of:
- Chlorine and bromine biocides,
- Anti-algae chemicals,
- Additional treatment agents.
Lower maintenance costs
Cleaner systems lead to:
- Less scaling,
- Reduced corrosion risks,
- Longer equipment life,
- Fewer shutdowns.
Return on investment is often achieved within 2 to 4 years, depending on system size and local water pricing.
Environmental advantages
Ozonation contributes to sustainability goals by:
- Reducing pressure on freshwater resources,
- Lowering chemical discharge into the environment,
- Cutting indirect carbon emissions from water production and transport,
- Supporting ESG and environmental compliance targets.
As data centers increasingly aim for carbon and water neutrality, water reuse becomes a strategic advantage.
Implementation considerations
While highly effective, ozonation must be integrated properly:
- Water chemistry still requires monitoring,
- Pre-treatment or filtration may be needed,
- Ozone handling requires safety systems and monitoring,
- System design must match cooling infrastructure.
Ozonation complements, rather than replaces, proper system engineering.
Conclusion
As data centers grow worldwide, reducing water consumption is becoming as important as reducing energy use.
Ozonation offers a practical and proven solution to:
- Improve cooling water quality,
- Enable water reuse,
- Reduce chemical consumption,
- Lower environmental impact,
- Decrease operational costs.
For operators seeking sustainable cooling solutions, ozonation is emerging as a key technology in next-generation data center infrastructure.