17 June 2026
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James Graham, Managing Director at BITZER UK, highlights that the choices made at the compressor level increasingly influence PUE optimisation, uptime resilience, and long-term regulatory compliance.
As hyperscale campuses expand and AI workloads push rack densities beyond 40 kW - and in some high-density deployments, past 80 kW per rack - cooling strategy is under renewed scrutiny1. Liquid cooling, rear-door heat exchangers, and advanced airflow management dominate industry discussions.
Yet, behind these innovations, the mechanical plant remains the backbone of performance. James, said: “Having anticipated the rapid rise of high-density AI workloads and liquid-cooled deployments, BITZER prepared early, ensuring key compressor platforms were stocked and ready to meet evolving data centre demands,” he says. “This foresight has allowed operators to plan expansions and upgrades with confidence, without being constrained by supply chain delays.”
In a sector defined by uptime percentages and fractional efficiency gains, compression strategy is no longer background engineering — it’s an operational lever that can make the difference between efficiency targets being met or missed.
Part-load reality in a 24/7 environment
Data centres rarely operate at steady full load. Hyperscale and colocation facilities are typically designed with N+1 or 2N redundancy, meaning cooling plant frequently runs at partial capacity2. IT loads fluctuate, ambient conditions change, and expansion phases alter demand curves.
“For operators chasing even small reductions in PUE, part-load performance is critical,” James notes. Modern screw and reciprocating compressor platforms combine mechanical capacity control with inverter-driven speed regulation. This allows precise modulation in response to real-time cooling demand.
The impact is tangible:
- Reduced energy consumption during partial loading
- Lower mechanical stress from excessive cycling
- Improved temperature stability in white space environments
- Extended equipment lifecycle
Across multi-megawatt campuses, incremental efficiency gains can translate into significant operational savings.
Liquid cooling and the continued importance of mechanical plant
Direct-to-chip liquid cooling and CDU-based systems are expanding rapidly in response to AI-driven heat density. However, the rejection of heat still relies on chilled liquid systems or refrigerant-based cycles. Even immersion and hybrid setups ultimately depend on the performance of the underlying mechanical plant.
James observes, “Liquid cooling reshapes white space design, but plant room engineering remains central. Efficient, responsive compressors still determine system-wide energy efficiency, temperature stability and reliability in high-density deployments.”
Intelligent compression and uptime protection
In Tier III and Tier IV facilities, cooling failure can cascade rapidly. Early anomaly detection is essential.
Modern compressors increasingly incorporate embedded monitoring modules with Modbus or similar communication capabilities, allowing integration into BMS and DCIM platforms3. This provides:
- Real-time operating data
- Oil and discharge temperature monitoring
- Application limit protection
- Fault trend visibility
- Remote diagnostics
“Moving intelligence closer to the component level allows operators to identify deviations before they escalate into critical events,” James explains. In mission-critical environments, this transparency materially reduces operational risk and supports SLA compliance.
Refrigerant strategy and long term risk management
Cooling plant decisions today must remain viable for decades. With accelerated F-gas phase-down schedules across Europe4 and growing scrutiny of Scope 2 emissions, refrigerant selection is increasingly strategic.
Large chiller applications now commonly utilise lower-GWP blends such as R1234ze and R513A, while natural refrigerants - particularly CO2 (R744) - are gaining traction in edge and urban deployments. These approaches allow operators to balance efficiency, regulatory compliance and sustainability objectives.
Heat reuse: From sustainability narrative to planning requirement
In parts of Northern Europe, planning consent for new data centres increasingly depends on credible heat reuse strategies5. Waste heat is no longer seen as a by-product but as a potential urban energy asset.
James notes, “Effective heat recovery depends on stable, high-pressure management within the compression cycle. Advanced compressor platforms enable elevated discharge temperatures that make district heating, commercial building integration, or industrial reuse feasible.”
As ESG-linked financing and carbon reporting intensify, these capabilities move from optional enhancement to commercial necessity.
Retrofitting legacy data centres
Europe hosts a substantial base of legacy cooling plants operating on older HFC systems. Full replacement is capital intensive.
Incremental upgrades, such as modern capacity control, inverter integration, or component-level intelligence, can improve efficiency and reliability without major redesign. James emphasises that even modest retrofits can help operators meet sustainability and PUE targets while extending equipment lifecycles.
Engineering decisions that outlast technology cycles
While AI acceleration, rising rack densities and sustainability pressures reshape data centre design, thermodynamic fundamentals remain unchanged. Cooling plant performance ultimately depends on how effectively mechanical energy is converted, controlled and protected at the compressor level.
Slide valve modulation, speed control, intelligent monitoring and refrigerant adaptability underpin every megawatt of cooling delivered. “As digital demand grows, operators must look beyond architectural innovation alone,” James concludes. “Understanding the role of the mechanical plant and compression strategy is increasingly central to achieving operational excellence.”
Source
1. www.techradar.com/pro/ai-workloads-are-reshaping-infrastructure-heres-what-data-centers-need-to-know
2. https://uptimeinstitute.com/resources
3. https://tinyurl.com/mpjy84wn
4. https://climate.ec.europa.eu/eu-action/fluorinated-greenhouse-gases/f-gas-legislation_en 5. www.velasolaris.com/en/data-center-heat-reuse
