AVIVA (aka Norwich Union) is set to open its third data centre – Data Centre 3 (DC3) at the Broadlands Business Park near Norwich, UK this September. Although the site uses some modern design principles to minimize energy use, AVIVA have been far too conservative with the design and the opportunity to really go green has been missed.
The site has been built to 2,250 square meters of raised floor in a single room, column-free space with capability to double in size; The site is designed with tier‐3 resilience (concurrent maintainability of all systems) at 1.5kW/square meter average with flexible low, medium and high density zones. The site will have full technical installation at day one and no planned outages or shutdowns for 15 years. The site uses a reasonably modern efficient design with some free cooling. So far so good, (apart from the high density zone) we get to the completely crazy piece later.
AVIVA have the option to install water‐cooled High Density racks, although (in my humble opinion) they would be crazy to do so. As a result of this design option AVIVA have set themselves unnecessarily strict design constraints directly causing ongoing poor cooling efficiency for the whole site.
AVIVA and their consultants have fallen into the trap of designing around the conventional Data Center design parameters with strict and tight temperature and humidity constraints that limit the viability of fresh air cooling. AVIVA have not implemented tight hot aisle / cold aisle containment systems to reduce hot and cold air mixing. As a result the same requirements produce the same energy hog design – a conventional data center.
AVIVA have stated that the internal environmental conditions had to be maintained within extremely tight parameters during failure scenarios: site power outage/generator start‐up/chiller restart and duty chiller failure/standby start‐up. Chilled water to the HD racks has to be maintained stable at less than +/‐1 degree C in these scenarios.
Why – those requirements are complete overkill even for high density racks?
There is a 7.6MVA grid supply, with an estimate of 6.8MVA maximum demand for phase 1 (assuming the DC3 is fully loaded). That’s 21,895 tonnes carbon dioxide per year with free cooling or 24,029 tonnes without (grid supplied electricity is 0.422kg carbon dioxide/kWh). Only the building and offices had to comply with Part L of Building Regs, as the process load is exempt. This is extremely poor exhibiting a bottom quartile PUE for the site.
In the Norwich area there are no local planning requirement for on‐site energy from renewable sources (unlike in London). The practical measures applied are: all AVIVA power is purchased on a green tariff from Scottish and Southern; there is free cooling and an elevated chilled water temperature of 10º C; there are variable speed drives on all fans and pumps, and UPS module optimization; there are zero ODP refrigerants; and heat recovery for on‐site offices and workshops. All good basic stuff.
AVIVA claim to have considered other renewables including photovoltaics (uneconomic) and wind turbines. AVIVA also considered ground source geothermal water source (but couldn’t get it to work as there was not enough ground water). All sensible decisions; however AVIVA rejected CCHP with absorption chillers which I think could have been helpful. AVIVA are still considering bio‐fuels a good local possibility but yet to happen.
A potential lies in low grade heat available for adjacent developments – AVIVA claim that “no‐one wants it.” Many other firms set up joint ventures and encourage the use of warm water for chemical and agricultural processes.
AVIVA is to close its DC1 centre which is 18 years old. DC2 is much newer and will continue. The DC3 IT migration begins this August, the first servers going live in September.
A missed opportunity and a great shame.