Cool Approach To Building A Hyperscale Data Centre | NGD Case Study

A cool approach to building out NGD’s hyperscale data centre  

By NGD 19 | November | 2018

Construction and supply chain best practices meet the need for speed

At 750,000 sq ft NGD is Europe’s largest data centre. For almost a decade the world class hyperscale facility has led the industry in pushing the boundaries of conventional data centre wisdom. Location, size, pricing, power capacity and commitment to 100% sourced renewable energy are just a few examples. Ongoing and significant investment in state of the art cooling and energy management technology has also made NGD an exemplar of data centre energy efficiency.

These attributes along with dense data connectivity have attracted global and local enterprises and global and local IT service providers. NGD is suited to meeting any customer requirement, from hosting the most demanding high density Cloud and High Performance Computing environments, to the colocation of hundreds, or a handful, of racks in highly secure and resilient environments. Most significantly, NGD has enjoyed 100% uptime since it started operations; this is no accident – NGD has taken great care in the design, specification, build and operation of its unique plant solutions.

Rapid Build Programme

At the heart of NGD’s business success is its ability to consistently leverage the vast space available and low cost base location to maximise economies of scale. A key factor has been the company’s rapid build programme which ensures the cost-effective delivery of individual data halls within an industry leading 16 week timescale. This is down to the expertise and prowess of NGD’s construction and engineering team and principal contractors, the hundreds of construction workers permanently on-site, and the flexibility of trusted suppliers.


Construction Director, Phil Smith,
on a cool approach to building out NGD’s hyperscale data Centre.

Known as ‘shell and core’ NGD’s construction model involves the shell of the building being built down into technical space on a just-in-time basis along with the associated external works for plant and facilities. This maximises capital efficiency and ensures a bespoke build to exact demands at any point in time.  Following this strategy, NGD successfully reached full capacity on the 250,000 sq ft ground floor of its three-storey building  early in 2018 with 31 halls fully occupied, representing 32MW of built space.

Phil Smith, NGD’s Construction Director, commented: “NGD has developed the ability to respond rapidly in delivering the private and shared campus space required to fulfil the exacting needs of our world-class customers. Our 16-week build programme allows us to meet demand and deliver quality quickly. However, to keep things moving at the right pace, suppliers work flexibly with us making adjustments to their products to keep the build schedule on time.

“The cooling solution provided by Stulz and Transtherm for the final ground floor expansion phase is a clear example of how data centres can work with trusted, reliable and dedicated supply chain partners.”

Stulz UK and Transtherm supply partnership

In this particular case, NGD had specified 114 data centre specific GE Hybrid Cooling Systems from leading manufacturer Stulz UK, plus a combination of 26 high performance horizontal and VEE air blast coolers and pump sets from industrial cooling technology specialist, Transtherm, to manage the inside air temperature of the campus expansion.

A three-part delivery solution

As long-term suppliers to NGD, both Stulz UK and Transtherm understood the importance of just-in-time deliveries so that the new air conditioning system did not impact the build speed on site. With a usual lead time of eight weeks for its GE Hybrid technology, Stulz UK set about devising suitable production alternations which would enable them to deliver their equipment within NGD’s rapid build programme.

Mark Vojkovic, Sales Manager for Stulz UK, explained: “Specified for installation into the floor of the new campus expansion, we altered the manufacturing process of our GE hybrid units to enable us to deliver the technology in two halves. First to be delivered were the fan bases, which were installed onto their stands during the earlier stages of the build, just in time for the construction of the suspended floor. Later in the build programme, between weeks 10 and 12, Stulz UK delivered the upper coil sections of the air conditioning units and Transtherm delivered, installed and commissioned their equipment on the outside of the building.”

Tim Bound, Director for Transtherm added: “Supplying a data centre superpower like NGD requires a reliable and creative supply chain solution which can not only work in tandem to deliver the most efficient product packages, but also communicate effectively to deliver products from multiple manufacturing sites ‘just-in-time’ in order to maintain their industry leading build-out times. It’s vital on projects of this size that manufacturing partners can see the bigger picture and adjust their own project parameters to suit.”

The technology in focus

The Stulz GE system utilises outdoor air for free-cooling in cooler months when the outside ambient air temperature is below 20°C, with indirect transfer via glycol water solution maintaining the vapour seal integrity of the data centre.

The indoor unit has two cooling components, a direct expansion (DX) cooling coil and a free cooling coil. In warmer months when the external ambient temperature is above 20°C, the system operates as a water-cooled DX system and the refrigeration compressor rejects heat into the water via a plate heat exchange (PHX) condenser. The water is pumped to the Transtherm air blast cooler where it is cooled, and the heat rejected to air.

In cooler months below 20°C external ambient temperature, the system automatically switches to free-cooling mode, where dry cooler fans are allowed to run and cool the water to approximately 5°C above ambient temperature before it is pumped through the free cooling coil. In these cooler months dependant on water temperature and/or heatload demands, the water can be used in “Mixed Mode”. In this mode the water is directed through both proportionally controlled valves and enables proportional free cooling and water-cooled DX cooling to work together. Crucially, 25% Ethylene glycol is added to water purely as an antifreeze to prevent the dry cooler from freezing when the outdoor ambient temperature is below zero.