Information technology - Data centres key performance indicators - Part 7: Cooling efficiency ratio (CER)

Overview

The standard defines the Cooling Efficiency Ratio (CER), which quantifies the efficient use of energy to control the temperature of spaces within a data centre. Its scope covers measurement, calculation, reporting and interpretation. Edition 1 was published on 10 March 2023 and runs to 16 pages. It is a paid standard; this record rests only on the publisher's public catalogue abstract and product metadata, and the full text was not read.

The annexes support use of the indicator: Annex A covers correlation with other KPIs, Annex B usage examples, Annex C the parameters that affect CER, and Annex D derivative KPIs. This structure shows the indicator is meant as a tool for interpretation and improvement, not merely a formula.

One significant exclusion applies: cooling systems not powered by electricity, for example heat-driven absorption chillers, fall outside the standard. A design that uses absorption chillers therefore cannot report CER in the sense of this standard.

As context, the standard belongs to the ISO/IEC 30134 family of indicators and is related to ISO/IEC 30134-2 (PUE) and EN 50600-4-7. The abstract does not detail the calculation method, so the standard itself should be consulted for formulas and measurement points.

Key points

1. CER quantifies efficient use of energy to control temperature of spaces within a data centre.
2. It covers measurement, calculation, reporting and interpretation.
3. Annex A: correlation with other KPIs; Annex B: usage examples; Annex C: parameters affecting CER; Annex D: derivative KPIs.
4. Cooling systems not powered by electricity, such as heat-driven absorption chillers, are excluded.
5. Edition 1, published 2023-03-10, 16 pages.
6. Related standards: ISO/IEC 30134-2 and EN 50600-4-7.
7. Paid standard; the record is based on the catalogue abstract only.

Using it in design

• In the cooling module, report CER from the hourly model as heat removed (kWh_th) divided by cooling-system electricity (kWh_e).
• Show CER as annual and per-season values.
• For designs with absorption chillers, disable CER and show 'n/a' per the scope exclusion.
• Read CER alongside PUE to isolate cooling-driven inefficiency.

Who should read it

Cooling design engineers and operations and sustainability teams preparing energy efficiency reports.

Related standards

• ISO/IEC 30134-2
• EN 50600-4-7

Publication details

Authors

ISO/IEC JTC 1

Publisher

ISO/IEC

Year

2023

Document number

ISO/IEC 30134-7:2023

Document language

English

Source type

Standard

Access

Citation only

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation