Back to News
Do you understand PUE at Part Load

When is PUE not PUE?

Date: 18th February 2016
Tags: , ,

When Data Centre designers and builders talk about the efficiency of the facilities they have designed and/or built in terms of the industry standard PUE, they often reference the design PUE. We look at why this can be misleading and why it is important to understand the difference.

This blog is part of a series looking at PUE and data centre monitoring; you can read our first post, which looks at what PUE is and why it is important here.

Design PUE – What is it?

When a new facility is designed, a PUE can be calculated based on the energy consumption of the proposed plant, cooling etc. as a measure of how efficient the solution could be. So why is this a problem?

Well, the PUE figure being quoted is often based on the premise that the data centre is actually running at 100% IT load. This is often unrealistic, as most data centres, especially in the colocation market build up their loads over time, with it taking anything from three years or more to get near to operating at full-load. In reality traditional data centre efficiency rapidly deteriorates at lower IT loads (most facilities never operate at 100%). This means that the suggested power efficiency levels will not come in to play for a significant time, if ever, and operating costs will be substantially higher than indicated by the Design PUE.

So what should you do to address this?

Whilst Keysource is reasonably unique in the fact that we have in-house design, project management and operation teams (which allow us to constantly feedback and learn from past projects) we would expect most data centre design and build companies to understand the fact that most facilities need to be efficient not only at full load but also at part load. They should take time with you to fully understand not only the technical requirements of the facility but also your business, so they can explain and work through this with you.

When this is not done it can cause problems as, understandably, it can have big impacts on your operating costs. This limitation of the PUE calculation is of particular importance to companies that are working to tight margins to provide for example, cloud services and colocation services.

To keep operational costs under control, it is often best to consult with specialist data centre designers. They will be able to advise you on the best technologies to deploy that drive down part load operating costs from the start and who will be able to work with you to fully meet your business and technical requirements.

Sounds good, but how can this work in practice?

We recently completed a data centre for colocation specialist; ITPS (read the case study). Part of our process was to really understand their business objectives and use our experience within the regional colocation market to propose a solution that would deliver not only the highest efficiency but also allow high densities to be deployed anywhere within the data centre. Knowing that this efficiency was needed from day one the design was built to be highly efficient at part load. To further enhance this a modular solution was used to allow ITPS to deploy more cooling and plant as required rather than having it all in place on day one.

If you would like to understand more about PUE you can read our previous posts which explain the different ways PUE can be measured or download the top 10 things you need to know about PUE. As you may have guessed, it’s one of the areas we are passionate about so please call us and speak to one of the team.

We are happy to talk you through any of the issues and answer any questions about your current or planned facility’s PUE and, if required, give you some more information on how you can increase the efficiency of your facility.

[x]

Contact Us

Please fill in the form below and a member of the team will be in touch shortly.