2025 Best Practice Guidelines for the EU Code of Conduct on Data Centre Energy Efficiency (JRC141521, EUR 40267)

Overview

The document is the full list of identified and recognised data centre energy efficiency best practices within the Code of Conduct, meant to help operators identify and implement measures. It provides common terminology and a frame of reference, and customers can ask suppliers for the list of practices they implement. It is a reference for the Taxonomy Delegated Act for climate mitigation and is mentioned in Article 12 of the 2023 Energy Efficiency Directive. Version 16.1.0 was released on 1 January 2025 and is the current edition.

Each practice carries a category tag: expected for all existing IT, mechanical and electrical equipment (Entire Data Centre), expected on new software installs, expected for new or replacement IT equipment, expected for data centres built or with a significant M&E refit from 2011 onwards (new build or retrofit), or optional. All expected practices should be applied to any data centre built from 2011 onwards. Each practice has a qualitative value from 1 to 5, with 5 the highest benefit; values are not meant to be totalled into an operator score.

Practices are grouped in nine sections: utilisation, management and planning (resilience, provisioning), IT equipment and services, cooling, power equipment, other equipment, building, monitoring, practices becoming minimum expected, and items under consideration. Examples: new IT equipment should operate within warranty across the full ASHRAE Class A2 allowable range (value 5); vendors should supply total system power at 100% load across the allowable inlet range in steps of 5 °C or smaller; AC/DC power converters should be rated at 90% efficiency or better across expected load ranges. Cabinet doors should have at least 66% perforated area per ISO/IEC 14763-2, with 80% an ideal target.

In cooling and power, facilities are expected to run efficiently within the ASHRAE Class A2 allowable range, widen humidity ranges, and use hot or cold aisle containment and blanking plates. Optionally, inlet conditions of 5 °C to 40 °C and 5% to 80% rh non-condensing, up to +45 °C in exceptional conditions (ETSI EN 300 019-1-3 Class 3.1), can be designed for, which can eliminate refrigeration in most climates. IEC 62040 UPS should perform as rated within 0 °C to +40 °C and 20% to 80% relative humidity. Resilience should be built only to the level business needs justify, and capacity provisioned for a maximum of 18 months of data floor capacity.

The monitoring section covers reporting of PUE, REF, ERF, CER, CUE, WUE and ITEEsv under EN 50600 and ISO/IEC 30134; PUE, REF, ERF and WUE reporting are expected practices. The document states that practices are qualitative recommendations, not mandatory limits, and that legal requirements take precedence over voluntary practices. An inapplicable practice needs a stated reason or an alternative with similar savings. Items such as software energy efficiency and an idle power target 20% below the Ecodesign value are under consideration.

Key points

1. Each practice is assigned a qualitative value from 1 to 5, with 5 the highest benefit; values are not meant to be summed into a score.
2. New IT equipment should operate within warranty across the full ASHRAE Class A2 allowable temperature and humidity range (Expected practice, value 5).
3. Vendors should supply total system power versus inlet temperature at 100% load over the full allowable inlet range, in steps of 5 °C or smaller.
4. IT equipment AC/DC power converters should be rated at 90% efficiency or better across expected load ranges.
5. Cabinet doors should have at least 66% perforated area per ISO/IEC 14763-2, with 80% considered an ideal target.
6. Data centres can optionally be designed for IT inlet conditions of 5 °C to 40 °C and 5% to 80% RH non-condensing, and up to +45 °C under exceptional conditions (ETSI EN 300 019-1-3 Class 3.1), potentially eliminating refrigeration in most climates.
7. UPS conforming to IEC 62040 should perform as rated within ambient ranges of 0 °C to +40 °C and 20% to 80% relative humidity.
8. Suggested target: idle-state power of new servers 20% below the value required by the EU Ecodesign Directive.
9. Provision power and cooling for a maximum of 18 months of data floor capacity, and build resilience only to the level business requirements justify.
10. PUE, REF, ERF and WUE reporting are expected practices; CER, CUE, ITEEsv and ITEUsv reporting are optional.

Using it in design

• Design the facility to operate within the ASHRAE Class A2 allowable range and require A2 operation within warranty in IT procurement; plan separate environmental zones (practice 5.3.4) for legacy equipment.
• Write airflow practices from section 5.1 into the design requirements: hot or cold aisle containment, cabinet blanking plates, brush seals and at least 66% perforated cabinet doors.
• In cooling design, consider widening inlet temperature and humidity ranges, free or economised cooling and, where appropriate, the expanded 5-40 °C range, and align IT purchasing policy with it.
• Set resilience and capacity by business need: 2N is frequently unnecessary; consider modular growth, provisioning for at most 18 months of capacity and different resilience levels for different areas.
• For UPS selection consider the Code of Conduct 2021 AC UPS elite requirements, modular UPS deployment, efficient operating modes and removal of needless isolation transformers.
• Build the monitoring architecture to report PUE, REF, ERF and WUE (EN 50600-4-x, ISO/IEC 30134), and address water metering, heat reuse and heat-pump-assisted recovery at the outset.

Who should read it

Engineers, operators and consultants who design, run or buy data centres, Code of Conduct participants, and customers who want a list of implemented practices.

Document contents

1. Document Information
2. Introduction: Role of Best Practices, Expected Minimum Practices, Value of Practices, Types of Participant
3. Data Centre Utilisation, Management and Planning
4. Resilience Level and Provisioning
5. IT Equipment and Services: Selection and Deployment of New IT Equipment
6. Deployment of New IT Services and Management of Existing IT Equipment and Services
7. Data Management
8. Cooling: Air Flow Management and Design
9. Cooling Management and Temperature and Humidity Settings
10. Cooling Plant: Free Cooling / Economised Cooling and High Efficiency Cooling Plant
11. Computer Room Air Conditioners / Air Handlers and Direct Liquid Cooling
12. Reuse of Data Centre Waste Heat
13. Data Centre Power Equipment
14. Other Data Centre Equipment
15. Data Centre Building: Physical Layout, Geographic Location and Water Sources
16. Monitoring: Measurement, Data Collection, Reporting and IT Reporting
17. Practices to Become Minimum Expected
18. Items Under Consideration

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Publication details

Authors

M. Acton; J. Booth; Daniele Paci

Publisher

European Commission JRC

Year

2025

Document language

English

Source type

Government / public

Access

Open licence — downloadable

DOI

10.2760/9449356

Licence

CC BY 4.0 — share with attribution

Licence evidence

publications.jrc.ec.europa.eu

Citation