Air Cooled Data

15 June 2009

How the Ecofris system works in principle

The first facility to adopt technology that can reduce the energy cost of operating data centres by over 45 percent can be found in Weybridge. Frank Booty visited the town to see the Keysource Ecofris cooling strategy in action

OIL EXPLORATION SURVEYOR PETROLEUM GEO-SERVICES (PGS) needed a high performance data centre solution at its head office in Weybridge, Surrey, that would significantly reduce power usage to achieve cost savings and a reduced carbon footprint. After a competitive tender, Keysource was selected to
design, build, install and manage the facility. The exercise is an example of how close cooperation between the business, finance, FM, IT and M&E sections is key to enabling efficient operations.

PGS is a global enterprise offering a range of products to the oil industry including seismic and electromagnetic services, data acquisition, processing, reservoir analysis/interpretation and multi-client library data. It helps oil companies find oil and gas reserves worldwide, offshore and onshore. To do its nvestigative and data collecting work, PGS operates a fleet of 24 boats, each one equipped with a basic data centre on board. Data in vast amounts is collected from many investigative processes, stored on magnetic tapes, pallets of which are delivered to key PGS data centres in Houston, Kuala Lumpur and Weybridge. At Weybridge,the data centre was included as part of a company relocation and the site is fed by two fibre dual 34Mbit/s links to provide the power.

“The data centre is to run for 10 years,” says Mike Turff, PGS global data centre manager. “There are no diesel generators, no chilled water, no air handling units and no CRAC, computer room air conditioning, cabinets. This means space is freed up and there is a good IT footprint. There is a raised floor but there is no use of this to distribute air and there are no holes – the floor is raised because we are on a flood plain, although the risk of any flood damaging us is minimal at 1:100.”

“We run a strictly batch operation with pallets of tapes being delivered containing all the data that needs to be processed,” explains Turff. “This means uptime while still critical is not as crucial as it is for many data centres. We have had one outage of a few minutes, but the UPS system kicked in and we were up and running again with no problems.”

Rising power costs can represent 25 per cent of the total cost of data centre ownership and more than 30 percent of a company’s overall energy usage. As PGS found, the Keysource Ecofris has proved to a highly-efficient, environmentally-responsible data centre solution.

It is the first facility to adopt Keysource’s Ecofris technology which can reduce the energy cost of operating data centres by over 45 percent. The PGS facility has been designed for 1.8MW of IT load and can accommodate high density IT hardware at any rack position with rack power densities of 30kW comfortably supported, easily accommodating the 15kW per rack specified by the PGS IT team.

“Air separation is the enabler to an efficient free cooling process,” says Keysource MD Mike West. “The UK climate is perfect for the free cooling process. The energy used is for thepump and fans – a few kW. The IT load is 83 percent of the power and cooling is 8 percent.”

The Ecofris design maximises the free cooling capacity and is only expected to require supplementary mechanical cooling for less than 100 hours per year – at PGS the figures are 83 hours. The cooling switches on when the ambient outside temperature reaches 25 degrees C. All power is fed to the top of the racks in the centre.

The modular nature of Ecofris means that design and installation times are kept to a minimum, avoiding unnecessary delays and operational downtime. Aspects of the solution are pre-assembled off-site and the fullycontained system can be sited externally to the data centre, as at PGS. Once electrical connections are made it is ready to ‘plug and play’. The lay-out and design frees up 40 percent operational space due to the absence of CRAC units and other equipment, and avoids the need for chilled water pipe-work to be installed inside the IT space.

Initial results confirm the data centre has achieved a Power Usage Effectiveness (PUE) ratio of 1.2 compared to a typical UK figure for a conventionally designed data centre of 2.2. A full IT load and compared to its previous site, PGS with its Ecofris strategy will reduce annual power consumption by 15.8m kW-h and reduce the emissions by 6,800 tonnes of carbon dioxide per year (based on UK grid average). In addition, the facility has a DCiE (Data Centre infrastructure Efficiency) of 80 percent, which means 80 percent of the total power being consumed by the facility is powering the IT kit.

West points out, “If you’re spending 8p per kW-h, having 15m kW-h savings per year speaks for itself, as well as the 6.8m tonnes of carbon dioxide emissions saved – you’re talking in excess of £1m per year savings.”

Keysource finalised the detailed design for PGS’s data centre including a new mains supply transformer, N+1 power and cooling solutions as well as supporting protection systems.

At Weybridge, outside air is drawn over wetlands and a river through an adiabatic cooling coil and filtered before being passed to the data centre. The roof plenum is utilised to pass hot air through to the venting system. The data centre build was managed by the Keysource’s project management team which delivered the project on-time and within budget, handing over the facility with server racks powered up and all network cabling in place to allow the PGS IT team to concentrate on populating the racks with the servers. Total cost of ownership and return on investment data could be applied across a 10 year period.
● Frank Booty is a freelance writer