Keeping the World’s Data Cool

4D Data Centres is a UK-based colocation provider, providing ultra-fast connectivity, business-focussed cloud and cyber solutions to organisations around the world. Data centres are at the heart of nearly all internet-based technologies, including Facebook, Google, WhatsApp and Amazon. Keeping all this technology online takes a lot of power, not only to run the computers themselves but also to keep them cool, otherwise they would quickly overheat.

When 4D took over an existing data centre building at Gatwick, Aqua was selected for its ability to upgrade the existing chiller-based cooling system, with installation and commissioning taking place whilst the facility was live. Working in direct partnership, Aqua designed and built an intelligent, energy efficient data centre cooling solution that significantly reduced the need for mechanical cooling and provided fresh air free cooling.

The project design focussed on a bespoke solution with energy efficiency, system resilience and reliability at its heart. It was critical that it was completely scalable, future proofing the client’s business model, allowing them to scale up to high density capacity at 40kW per rack when market demand required. Aqua’s ‘water tower’ system uses evaporative cooling to lower the temperature of the computers in the data centre.

Evaporative cooling used in this way is very innovative in the UK but at its heart it’s the same process that we as humans use to cool ourselves down. When we get hot, we sweat and it’s this process of water evaporating off the skin which cools us down. Legacy chillers were replaced with a “chiller-less” solution, using a cooling tower alongside a packaged plant room and full water treatment facility. The design included pumps, heat exchangers, dosing equipment, filtration, inverters and remote monitoring.

Specially designed CRAC (Computer Room Air Conditioning) units which operate on a 2°C difference between air and water temperatures, enable the system to run at higher temperatures. This eliminates the need for compressors – or mechanical cooling – allowing the chillers to be replaced with natural source cooling (cooling towers). This also reduces the number of moving parts within the design which increases system reliability.

In addition, using Carel’s CPco Platform, the system’s control strategy was engineered to minimise energy usage. The monitoring technology is aware of the minimal energy requirements for each piece of equipment within the system, ensuring it runs at the optimal needs of the data centre, with zero energy wastage. A bespoke square pipework system was designed with dual – or 2N – redundancy, so there is no single point of failure. If an issue should ever arise, it can be resolved without interruption or downtime in the data centre.

The full solution included:

• Bespoke design service
• Full installation and commissioning including turnkey pipework
• Cooling towers
• Packaged plant room/water treatment facilities
• Pumps, heat exchangers, filtration, inverters and Carel CPco monitoring and control system
• CRAC units

Project Engineers restricted the work carried out within the live facility to a minimum. For example, pipework was all pre-manufactured off site and then bought in for final assembly. Final commissioning had to be carefully phased, to avoid any unnecessary swings in supply temperature. The design of the Gatwick facility also caused some challenges. For example, the existing raised floor with cable trays in situ meant pipework had to be carefully routed and specially designed in areas as there were limited places to cross over.

Energy efficiency and subsequent cost savings were immediately evident, in the autumn months consuming significantly less than the previous system. The annual energy saving compared to the old system is forecast at 90%+, with an annualised part load Power Usage Effectiveness (PUE) of 1.125. For 4D’s business, they have a facility that they can now scale right up to high density capacity of 40kW per rack.

Benefits achieved included:

• Power Usage Effectiveness (PUE) of 1.125 (ratio of total facility power usage divided by
  IT equipment power usage)
• 90%+ energy saving on legacy cooling system
• Future-proofed, modular, scalable design – from low density to high density – as
  demand dictates
• 2N redundancy – zero risk of downtime
• Constant temperature, humidity and leak detection monitoring
• Green installation – major statement of intent by 4D to reduce carbon footprint

“The single biggest challenge of the project was installing and commissioning within a live data centre environment. Aqua’s diligent planning ensured zero risk of client downtime and provided us with a fast, reliable, greentech solution with tangible energy savings” – Steven Wright, COO, 4D