Protecting Mission Critical Systems using Technical Cleaning and Particulate Matter Control in Data Centres

Organisations typically invest heavily in IT and data equipment, which are often referred to as ‘mission critical’ due to their essential role in daily operations. Uninterrupted operation is vital, but contamination incidents can compromise this. Stephen Yates from IT Cleaning emphasises that such equipment is best housed in purpose-built computer rooms or data centres—often called critical environments—either on company premises or in collocated facilities. These spaces form the heartbeat of most organisations, with systems in place to ensure continuous equipment performance.

Examples include uninterrupted power supplies, effective fire suppression, and reliable cooling. As IT equipment becomes increasingly powerful through advanced processing and miniaturisation, managing airborne particulate contamination in these environments is as important as other safety measures.

Impact of Airborne Particulate Matter

Airborne particulate contamination can cause anything from catastrophic equipment failure to higher cooling and power demands. Original Equipment Manufacturers (OEMs) are now specifying cleanliness requirements for their equipment’s operating environment—such as ISO 14644 Class 8—with the risk that failing to comply could void warranties.

Sources of Particulate Matter

When acknowledging the presence of particulate matter (PM) in data centres, several sources must be considered before implementing technical cleaning as part of quality control.

• External Sources: Particulates can enter from outside the facility. The adoption of economised or ‘free air’ cooling systems, which use M6 or G4 filters (filtering 1.0–10.0 μm particles), allows smaller particles to pass into data halls. Environmental assessments are necessary, especially if economisers are in use, to detect external contamination sources such as car parks or railway stations. Other entry points include open doors, standard ventilation, human activity (clothing and skin shedding particles), and equipment or shoes carrying dust indoors.
• Internal Sources: Dust is also generated within the data hall. For instance, neoprene drive belts on CRAC downflow units—operating continuously—produce particulate matter as they wear down.

Once inside, these particles are moved by airflow, conduction, Van der Waals forces, static, Brownian motion, and only minimally by gravity due to their tiny mass. Eventually, particulates can infiltrate sensitive IT equipment, leading to multiple issues.

Effects on IT Equipment

The specific effects of PM depend on its type and may fall under four categories:

• Mechanical Effects: Obstructed airflow (causing overheating), interference with moving parts, abrasion, optical interference, interconnection issues, and even deformation of surfaces such as magnetic media. For example, abrasive plaster dust from refurbishments can insulate PCB components and worsen heat problems.
• Electrical Effects: Impedance changes or electronic circuit bridging, particularly from conductive particles like zinc.
• Chemical Effects: Certain types of dust, once settled on PCBs, can cause corrosion (e.g., copper creep) or electrical short circuits.
• Absorption of Moisture: Particulate matter with high deliquescence relative humidity (such as plaster dust) can absorb moisture, become conductive, and increase abrasion. Such dust may also lower room humidity, raising static risks.

Given these risks, controlling PM in data halls is crucial for all stakeholders who depend on equipment reliability.

Strategies for Contamination Control

To control particulate contamination, begin with a thorough assessment of indoor PM—including its composition and origin—through sampling and laboratory analysis. Findings may indicate, for example, neoprene particles from ACU drive belts, prompting targeted responses such as coordination with service suppliers or equipment manufacturers. These steps may include implementing technical cleaning.

If economisers are used, further outside environment analysis helps identify contamination sources. For instance, if a data centre’s economiser system is drawing in fine silicate dust (from a nearby concrete plant), management can then address the external source and adjust internal processes accordingly.

Best Practices in Technical Cleaning

Technical cleaning is now a recognised method for controlling PM in data centres. Current best practice specifies cleaning the data hall to ISO 14644-1 2015 Class 8, with all accessible surfaces free of dust. This dual approach addresses airborne and settled particulates, giving data centre managers a verifiable standard.

Key considerations for technical cleaning include:

• Managing Airborne Particulate Levels: Compliance with ISO 14644-1 2015 Class 8 requires airborne particle control during cleaning, as activities like vacuuming and wiping can resuspend settled dust.
• Removing PM from All Accessible Surfaces: Appropriate tools and procedures must be used, with clear agreement between management and cleaners about what counts as accessible.
• Testing: Post-cleaning, airborne particulates are tested according to ISO 14644-3 using calibrated air particle readers, while settled particulates are checked with a ‘glove test.’ Any dust found is a fail, with data centre management conducting these tests.
• Reporting: A validation certificate and report, documenting test results and observations, should be produced. This is valuable for audits and demonstrates compliance to clients and users.

Conclusion

Particulate matter will inevitably be present in data centre environments, which are not true clean rooms. Nevertheless, technical cleaning to ISO 14644-1 2015 Class 8 remains a critical tool for managing contamination. Many large centres include this in standard operating procedures, and specifications for cleaning and validation are common prior to facility handover.

While essential, cleaning and testing should be complemented by other environmental controls—such as a ‘no cardboard’ policy, regular maintenance, and simple solutions like barrier mats at entrances—to reduce particulate contamination and protect mission critical IT infrastructure.