When ISP Star began commissioning a new datacentre, its head of hosting strategy James Griffin gave his team a challenging brief. "I told them the datacentre had to be agile, flexible and commercial, with no over-engineering and a quick return on investment," he says.

Griffin also set out a number of project requirements: each rack was to consume no more than 7kW of electricity; the site had to be operational before May 2009; and it had to come in on budget.

The chosen site at Abbey Wood in Bristol had previously housed a datacentre operated by ISP Demon. One of Griffin’s early challenges was getting enough power to the facility. "However, a few phone calls to South West Electricity resulted in them offering us 3 megawatts of electricity supply," says Griffin.

Among Griffin’s first priorities was to put in a back-up power supply. “It was useless thinking about which servers to use until this part of the project was specified,” he says.

Griffin decided early on against a battery-based UPS system. "It would take a 250kW chiller to cool battery UPS and 70kW for charging," he explains.

Instead, Star opted for a friction-free flywheel system, which needs only 9kW of power.

"We bought the flywheel and the actual standby power generators from critical power system vendor Active Power – giving us a single throat to choke – and we can add extra flywheels as and when needed. The flywheels give 45 seconds of power and our Smart Start system fires up the standby generators in 12 seconds, " says Griffin.

To achieve the 7kW per rack target, network cabling could not go under the floor but had to be attached to the top of the racks.

The datacentre was fitted out with category 6a (Cat 6a) copper, capable of handling gigabit and 10 gigabit network speeds. In all, 125kg of cabling was used in the datacentre, and given that it was not under the floor, there was "a huge void in the under floor cavity available to push air around the system," says Griffin, “which helps improve cooling.”

Star was also faced with "a real curve-ball" when Filton Town Council insisted that the datacentre complied with new noise regulations. "We had to spend £26,000 on acoustic baffling for the chillers," says Griffin, ensuring operating noises did not exceed the 40dB limit at a distance of 10 metres from the facility.

Ultimately, the careful planning should ensure that when the datacentre is fully operational it will provide huge amounts of computational power without a massive power overhead. In effect Star has built a 4,000sq ft facility that is "the equivalent of a 16,000 to 20,000sq ft one," says Griffin.