Overview
ISO/IEC 30134-7:2023 defines the Cooling Efficiency Ratio (CER) as a key performance indicator (KPI) for data centres. The CER quantifies how efficiently a data centre uses electrical energy to regulate internal temperatures via its cooling systems. This international standard provides a consistent methodology for measuring, calculating, and reporting CER, enabling data centres worldwide to benchmark and optimize energy usage related to cooling. The document specifically focuses on electrically powered cooling systems, excluding heat-driven absorption chillers and other non-electric cooling technologies.
The standard is part of the broader ISO/IEC 30134 series, which provides holistic guidance on data centre key performance indicators for resource usage effectiveness and sustainability. Using CER, facility managers can make informed decisions about operational efficiency, sustainability, and reporting requirements.
Key Topics
- Definition of CER: The Cooling Efficiency Ratio (CER) is the ratio of total heat removed from the data centre to the amount of electrical energy consumed by its cooling system over a specified period, typically annually.
- Measurement and Calculation: The standard outlines requirements for measuring both the heat removed (in kWh) and the electrical energy used for cooling, ensuring both are recorded over the same time frame. Accurate measurement is essential, and remote metering with data history is recommended.
- Reporting Requirements: CER results must be reported with contextual information, such as facility details, measurement periods, environmental conditions, and the associated Power Usage Effectiveness (PUE).
- Application Guidance: The CER can be applied to both dedicated data centre cooling systems and shared systems in multi-use buildings. Annexes provide additional context, including correlations with other data centre KPIs and real-world usage examples.
- Factors Influencing CER: Variables such as coolant temperature settings, airflow rates, and pump efficiency can affect the CER, highlighting operational aspects that can be optimized for better energy efficiency.
Applications
ISO/IEC 30134-7:2023 is especially valuable in operational, design, and management contexts:
- Operational Benchmarking: Data centre operators can use CER to benchmark cooling efficiency year-over-year or compare against other facilities, driving continuous improvement in energy management.
- Performance Optimization: By tracking CER, facility managers can identify underperforming cooling systems and implement improvements, such as adjusting temperature setpoints or optimizing airflow and pump operations.
- Sustainability Reporting: CER provides credible metrics for environmental sustainability initiatives, serving as evidence of energy optimization in cooling, which is a significant component of overall data centre power consumption.
- Stakeholder Communication: Reporting CER with supporting context enables transparency with regulatory bodies, auditors, clients, and the public, building trust and supporting compliance with sustainability standards.
- Design and Planning: Engineers and architects can use CER data to inform design choices for both new and retrofitted facilities, helping to meet efficiency targets and reduce operational costs.
Related Standards
For a comprehensive approach to data centre efficiency, consider these related standards:
- ISO/IEC 30134-1: Information technology – Data centres – Key performance indicators – Part 1: Overview and general requirements. Establishes the KPIs framework for resource efficiency.
- ISO/IEC 30134-2: Information technology – Data centres – Key performance indicators – Part 2: Power usage effectiveness (PUE). Focuses on the overall energy efficiency of data centres.
- ISO/IEC 30134-6: Information technology – Data centres – Key performance indicators – Part 6: Energy re-use factor. Supports measurement of energy re-use efficiency within data centre operations.
- IEC 62052/IEC 62053 series: Standards for electrical metering, referenced for ensuring accurate measurement of energy consumption.
Practical Value
Adopting ISO/IEC 30134-7:2023 delivers practical benefits for data centres seeking to:
- Lower energy costs by identifying and reducing inefficiencies in cooling.
- Support green data centre initiatives by documenting and improving cooling energy usage.
- Meet regulatory and customer expectations around resource efficiency and transparent environmental reporting.
Utilizing the CER according to this standard enhances the data centre industry’s efforts toward greater sustainability, operational efficiency, and overall performance in a rapidly expanding digital landscape.
Open preview (PDF)Information technology — Data centres key performance indicators — Part 7: Cooling efficiency ratio (CER)
