Reducing Risk in the Data Centre: Beth whitehead, July 2018.
Special report: Data centres, the auto industry and the cloud: AutomotiveWorld, July 2018.
Data Center Sustainability Index, Robert Tozer, Sophia Flucker, Beth Whitehead, Deborah Andrews, Jon Summers, ASHRAE Winter Conference & AHR Expo, 20 - 24 January 2018, Chicago.
  Playing the long game, R.Tozer, S.Flucker, B.Whitehead, CIBSE journal April 2018.
European code of conduct on data centre energy efficiency participant usage guide, Operational Intelligence, January 2018.

Data Centre Sustainability - Beyond Energy Efficiency, Sophia Flucker, Robert Tozer, Beth Whitehead, Building Services Engineering Research and Technology Vol 39, Issue 2, 2018 ***

Virtual Roundtable: Beyond energy efficiency- A holistic approach to data centre sustainability, Sophia Flucker, September 2017.
Minimising Data Centre Environmental Impact – Beyond Energy Efficiency, Sophia Flucker, Beth Whitehead, Robert Tozer, Technical Symposium Loughborough University, 5 April 2017.
Energy and Water Environmental Trade-Offs of Data Center Cooling Technologies, Beth Whitehead, Robert Tozer, Deborah Andrews, Sophia Flucker, ASHRAE Conference Las Vegas, January 2017. *
Data Centre Air Management Introduction, Robert Tozer's video.
  On the right track, Beth Whitehead, DCM, Spring 2016, pages 23-24.
  Energy efficient technologies for data centres, European Energy Innovation, Spring 2016, pages 57-58.
  Combined Processing Power, Data Centre Collaborative Working, CIBSE Journal June 2016.
Reducing data centre risk and energy consumption through stakeholder collaboration, Robert Tozer, Sophia Flucker, David Cameron, CIBSE Technical Symposium, 14-15 April 2016.
The Case for Sustainability in Data Centers, Robert Tozer, Sophia Flucker, Beth Whitehead, ASHRAE Transactions, Volume 122, Part 1, 2016. *
Data Center Trigeneration with Absorption Refrigeration and Economizer Technologies, Robert Tozer, ASHRAE Conference Chicago 2015. *
Data Center Air Segregation Efficiency, Robert Tozer, Beth Whitehead, Sophia Flucker, ASHRAE Conference Chicago 2015. *
Data Centre Energy-Efficiency Improvement Case Study, Robert Tozer, Beth Whitehead, Sophia Flucker, ASHRAE Conference Chicago 2015. *
  How Iceland is Reeling in its Newest Catch: Global Data Centers Mark Halper, Communications ACM, 22st October 2015.
  Central Intelligence, IST for knowledge transfer, David Cameron, FMWORLD April 2015.
Opportunities for Combined Heating and Cooling Using Data Centres, G.F. Davies, G.G. Maidment, R.M Tozer, CIBSE Technical Symposium, London, UK 16-17 April 2015
There's a business case for sustainability, Robert Tozer, DCD at CeBit, 31st March 2015.
The life cycle assessment of a UK data centre, Beth Whitehead, Deborah Andrews, Amip Shah, The International Journal of Life Cycle Assessment, March 2015, Volume 20, Issue 3, pp 332–349. **
  Assessing the environmental impact of data centre part 2: Building environmental assessment methods and life cycle assessment, Whitehead et al. (2014) Building and Environment. doi: 10.1016/j.buildenv.2014.08.015.
  Assessing the environmental impact of data centres part 1: background. energy use and metrics, Whitehead et al. (2014) Building and Environment doi: 10.1016/j.buildenv.2014.08.021.
  Meeting climate change targets in the UK, Beth Whitehead, DCD Focus, September/October 2014, pages 32 - 33.
  Improved resilience through reduced complexity and increased training, Beth Whitehead and David Cameron, datacentre solutions, July 2014, page 19.
  Measuring Environmental Impact Using Life Cycle Assessment, Beth Whitehead, DCD Focus, May/June 2014, p73.
Data centre air segregation efficiency, Robert Tozer, Sophia Flucker, CIBSE ASHRAE Technical Symposium, Dublin, Ireland, 3-4 April 2014.
  Organisational learning in the Data Center, Beth Whitehead, DCD, 21st January 2014.
Scalable Data Centre Efficiency, Robert Tozer, Sophia Flucker, Alejandra Romano, CIBSE Technical Symposium Liverpool 2013.
  Complexity and the Human Element, David Cameron, DCD Focus Magazine, Issue 30, July/August 2013
  How Cooling has Heated up the Data Center Discussion, Robert Tozer, DCD Focus Magazine, Issue 30, July/August 2013: p32.
Data Centre Energy Efficiency Analysis to minimize total cost of ownership, Sophia Flucker, Robert Tozer, Building Services Engineering Research and Technology, vol. 34, 1: pp. 103-117. 2012 ***
Zero Refrigeration for Data Centres in the USA, Robert Tozer, Sophia Flucker, ASHRAE Summer Conference San Antonio 2012. *
  CIBSE KS18. Data Centres: an Introduction to Concepts and Design, 2012.
Minimising Data Centre Total Cost of Ownership Through Energy Efficiency Analysis, Sophia Flucker, Robert Tozer, CIBSE Technical Symposium London 2012.
The Environmental Burden of Data Centres - A Screening LCA Methodology, Whitehead et al., CIBSE ASHRAE Technical Symposium, London, 2012.
The Screening Life Cycle Assessment of a Data Centre, Whitehead et al , avniR Conference, Lille, 2012.
Data Centre Cooling Air Performance Metrics, Sophia Flucker, Robert Tozer, CIBSE Technical Symposium Leicester 2011.
Air Performance, Robert Tozer, 2011.
Intelligent Reduction of Operating Costs, Robert Tozer, 2011.
Data Centres: The Human Element , Webinar presented by David Cameron, 6th December 2011.
Global Data Centre Energy Strategy, DCD notes, Robert Tozer, 2009.
Air Management Metrics in Data Centres, Robert Tozer, Munther Salim, Chris Kurkjian, ASHRAE Transactions, vol. 115, part 1, Chicago meeting, CH-09-009, 2009. *
Cooling Challenges for Mission Critical Facilities, Robert Tozer, Martin Wilson, Sophia Flucker, Institute of Refrigeration, Session 2007-2008.
An Approach to Mission Critical Facility Risk, Robert Tozer and Ed Ansett, CIBSE Conference 2006.
Reliability Engineering for Financial Institutions, Robert Tozer & David Cameron, 2001.
Thermoeconomics Applied to HVAC Systems, Robert Tozer, Miguel Angel Lozano, Antonio Valero, ASHRAE Transactions, 1999. *

* This paper is published by ASHRAE and posted here with permission
** Originally published by Springer
*** Reprinted by permission of SAGE Publications
It can be difficult and frustrating to receive organisational funding and project approval. By holistically analysing which initiatives deliver the maximum benefit, operators can prioritise improvements and produce a strong business case to approve changes to reduce energy and mitigate risk.


In 2014, OI and the Operations team of a global finance service firm achieved a PUE reduction from 2.3 to 1.49, an exceptional result for a legacy data centre. Through energy assessments and operator education workshops we implemented air management improvements, optimised fan control and increased air and chilled water temperature set points to reduce energy costs and achieve significant financial savings. We also installed an indirect free cooling circuit.


At OI we believe the data centre industry is starting to recognise that its focus must go beyond energy consumption. Single-issue metrics such as PUE only consider the operational phase and cannot fully capture the interlinked nature of the data centre system. An improvement in one area can adversely affect a totally different area with the operator remaining oblivious. Using operational efficiency as a proxy for sustainability has to stop. This paper explains exactly why.


Data centres consume large amounts of energy and are rapidly growing in size and numbers. Inefficient air segregation can cost facilities a lot of energy wastage and increases risk of downtime. It is difficult to quantify the efficiency of air separation. Thus, we introduce a new metric that helps data centre operators calculate total air segregation efficiency. The tool is robust and scalable, it does not need complicated software or an abundance of data and can provide the platform from which many improvements can be identified.


In many USA climates 100% free cooling is possible. Significant operational and capital cost savings can be realised. With segregation of hot and cold air streams by hot aisle, cold aisle or exhaust containment systems, zero refrigeration is possible. As temperatures get hotter, the benefits of indirect cooling systems are greater.