This document specifies the cooling efficiency ratio (CER) as a key performance indicator (KPI) for quantifying the efficient use of energy to control the temperature of spaces within a data centre (DC).

This document:

a)    defines the CER of a DC;

b)    describes the relationship of this KPI to a DC’s infrastructure, information technology equipment and information technology operations;

c)    defines the measurement, the calculation and the reporting of the parameter; and

d)    provides information on the correct interpretation of the CER.

Annex A describes the correlation of the CER and other KPIs.

Annex B provides examples of the usage of the CER.

Annex C introduces the parameters that affect the CER.

Annex D describes requirements and recommendations for derivatives of KPIs associated with the CER.

This document is not applicable to cooling systems that are not powered by electricity (e.g. heat-driven absorption chillers).