Why some data centres age faster than expected

Picture a data centre suddenly becoming non-functional. Key systems like cooling, ventilation or generators may seem fine, making it hard to immediately diagnose the issue. The cause could be corrosion. Unseen in the air, it can degrade key components like circuitry, slowly and over time, though enough to trigger a full shutdown. With data centres so important to our daily lives, maintaining operational stability is key, yet not all the risks to this are easy to see.  

Data centres are designed to operate within tightly controlled environments. Temperature, humidity, power demand, and airflow are carefully managed to protect infrastructure and ensure long-term reliability. Yet, atmospheric corrosivity is often less understood and more overlooked.

Airborne corrosive pollutants, such as sulphur dioxide, nitrogen dioxide, ozone, acidic aerosols or even chlorides and hydrogen sulphide, together with humidity or salinity and the accumulation of dust particles, can speed up the decay of metallic components. This is a huge source of concern for the electrical systems and other sensitive equipment that keep servers running. Whilst the impact in any given day is rarely immediate or dramatic, like a power or cooling issue, corrosion slowly shortens lifecycles, increases maintenance costs, and raises the risk of unexpected failures. For operators of high-value data centres, this can be a huge risk. Atmospheric corrosivity testing can help prevent this.

What does corrosivity testing do?  

Atmospheric corrosivity varies widely by location. Even in the same facility, it can vary significantly across environments, plant areas, or internal spaces. Some data centres located close to the coast for access to water are likely to be located in areas of higher airborne salinity, while urban or industrial locations may have to contend with more sulphur or nitrogen-based pollutants. Additionally, the site conditions can be heavily influenced by local meteorology. To address this, testing can provide data to inform ventilation strategies and the design of improved filtration systems which can mitigate the impact of these factors on sensitive data halls.

This data-led approach is vital and helps operators save costs. Oftentimes, in the absence of data, corrosivity risk is often managed through worst case assumptions. This means that operators will often replace filters, seals, or components annually by default. By understanding how corrosion is expected to affect the equipment, operators can reduce their long-term maintenance costs and keep equipment longer when the risk of corrosion is low or increase resilience by replacing equipment sooner when it is high.  

Through atmospheric corrosivity testing, engineers can reduce the gap between assumptions and reality. It enables operators to make decisions with full information and understand how corrosive their environment really is, leading to targeted risk management strategies for the specific location.  

How does the testing work?

Atmospheric corrosivity testing assesses environmental conditions that influence the corrosion process. Typically, this process involves deploying corrosion test coupons, monitoring environmental conditions, analysing data to identify trends, and acting on findings to mitigate risks. These stages are built from surveys that combine on-site monitoring with further analysis to predict trends.

A core element of the on-site testing is the deployment of corrosivity test coupons. These are based on copper and silver and provide a direct indication of how corrosion-sensitive materials react to the environment over time. This data can be supported by consideration of background pollutant concentrations to identify the potential for the main corrosive agents in the environment. Typically, these are sulphur, nitrogen, and hydrogen sulphide. Temperature and humidity levels are assessed, as they can also increase corrosion of materials and equipment.  

Where required, particulate matter mass and particle size distribution measurement scan be used to assess potential risks from both corrosive and non-corrosive particulate matter. This helps to determines the size and variability of all particulate materials, and the collected data will inform ventilation and filtration design.  

The collected data is usually analysed and classified in accordance with recognised international standards. These are mainly ANSI/ISA-71.04 and ISO 9223/9224. These standards provide a common framework that categorises the environment’s corrosivity from very low to extreme. These categories help inform operators, engineers, and designers in location and equipment choices.

What is the benefit?  

For data centre operators, the value in testing lies in the data it generates. The test results can inform decisions that will significantly impact the lifecycle of key assets in the building.  

Early identification of corrosive environments helps to prevent the gradual degradation of components. Without the testing, this may go unnoticed until a failure occurs. By understanding where corrosion risk is high, operators can create maintenance schedules more effectively and focus their efforts where they are needed most, saving both time and money.  

On the other side, testing ensures that costs are saved by no longer using blanket worst case maintenance measures. By understanding how the atmosphere differs even within the same building, changes can be made to localised areas rather than implemented simultaneously across the entire data centre. This not only saves costs by avoiding the replacement of equipment that is still operational but also reduces disruption to live facilities.  

It is also good to look more long-term, as data centres can remain operational for decades. By regularly documenting environmental conditions, operators can make long-term decisions with more information. Monitoring for corrosion enables the identification of specific pollutants, to help spot emerging trends. Visual tools, such as charts or graphs that plot corrosivity levels over time and their relationship to failure rates, can highlight the advantages of consistent monitoring for future site selection and risk management. The data is highly valuable for decision-making in risk management.

Moving to an evidence-led approach

Data centres are expensive facilities filled with sensitive equipment that must remain operational at all times. Power availability and equipment resilience are the two big factors for operators, and while parts of the design, like cooling and electrics, are important, the impact of the air can’t be understated. Through atmospheric corrosivity testing, engineers can bring a data-led approach to risk management, saving time and influencing future design decisions.  

With clear evidence, operators can make better decisions about maintenance and investment. Given the value of the assets and the criticality of their operations, protecting them from unseen dangers should be a top priority.  

Reach out to a member of our air quality team if you would like to learn more or schedule a corrosivity assessment for your data centre to safeguard against corrosion risks.