What is PUE

Power Usage Effectiveness (PUE) is the ratio of data centre total energy consumption to information technology equipment energy consumption, as defined in BS EN 50600-4-2:2016 3.1.3. It is an industry recognised Key Performance Indicator that measures the efficiency of a data centre. In an ideal situation where all energy coming into the facility is used by the IT equipment, the PUE would be 1.

At RED Engineering, sustainability is a core principle driving the design process. To help our clients meet their targets, including PUE, we use assuRED and Briza, to inform on data centre KPIs at early design stage and throughout the design process.


RED has developed a tool to provide early indications of data-centre efficiency metrics across different locations and design configurations. By selecting a specific geographical location, assuRED provides an estimation of PUEs for a variety of designs, hence giving insights into the impact of location and cooling technology on energy demand. In recognition of its versatility, assuRED won the Tractebel innovation award in 2017 for ‘Commercial and Customer Relations’.

Assured Tool

Check out the PUE for your project using our state-of-the-art calculator 


View assuRED Calculator

assuRED uses global weather information with models of data centres representing a variety of cooling infrastructure and levels of resiliency. These models were created by RED engineers drawing on design experience and manufacturer data to provide a representative estimate of performance.


“A generic modelling tool for the flow of energy and water in complex process dominated building systems, including data centres”

Briza is used by engineers at RED to deliver analysis of data centre KPIs, such as PUE, Water Usage Effectiveness and Carbon Usage Effectiveness during the design process. These models represent the flow of electrical and cooling energy within the data centre, and are developed using project specific design and manufacturer information.

The tool provides a high level of insight into the performance of the system which allows, for example, the impact of control strategy on performance to be quantified. PUE analyses using Briza are recommended to be undertaken at all stages of the project to ensure that the project energy efficiency targets are met.


Advanced system types such as sea water or river water-cooled systems can be modelled, in addition to more traditional system types such as mass air indirect and direct systems, chiller and cooling tower based systems, among others. This results in a comprehensive energy, water and carbon modelling package that can provide useful metrics to inform the design process.

Applications of Briza

  • PUE, WUE and CUE analysis of data centre design from Stage 2 to Stage 4.
  • Planning PUE analysis reports.
  • Evaluation of tender proposal impacts on PUE, WUE and CUE data centre metrics.
  • BREEAM supporting analysis of data centre energy efficiency .
  • Evaluation of energy savings associated with an equipment retrofit for a manufacturing facility.
Applications of Briza

Briza Features


Increased Insight

Details of air and water movement, heat and energy flows, PUE and WUE benchmarking and comparison.


Improved Visual Output

Improvement of visual output for client presentation with interactive charts and elements.

Magnifying Glass

Improved Quality

Improved modelling quality due to easier review/quality audit.


Flexibility & Capability

Ability to model to the required level of detail, including COP tables & efficiency curves.

Further Information

If you would like to know more on any of these tools or would like further information, please contact us.


Find out more about Briza

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