Computer room at BGS Keyworth
In 2009 NERC gave approval for the construction of a new computer room at BGS Keyworth. The previous room was full to capacity and the critical services were reaching the end of their life.
Most of the NERC computer rooms are housed in existing buildings that were designed as offices or ancillary space. This is the first time a separate building housing a purpose-designed computer room has been constructed by NERC.
As with all NERC construction projects, the brief to the design team was to provide a building with a strong emphasis on sustainability.
The principal sustainability driver was to achieve a BREEAM 'Excellent' rating. Following a number of discussions with the Building Research Establishment (BRE) the project was selected as a pilot for the 'BREAAM Data Centres 2010' category. The 'Excellent' rating was achieved for the design stage in April 2010 with a commendable score 75·70%. The post-construction stage has just been submitted to BRE with a score of 73.98% - again achieving the 'Excellent' rating.
A further requirement was that the room should achieve and EPC (Energy Performance Certificate) 'A' rating. This too has been achieved with an excellent score of 17 (the maximum for this rating being 25)
All electrical and mechanical services are controlled and monitored through the existing BGS BMS (Building Management System) The comprehensive inputs to the BMS allow full recording of all energy usage and plant settings so that ongoing performance and energy use can be monitored.
Computer rooms are power hungry. Globally this year they are expected to use c 100 billion kWh. A second benchmark success factor was to achieve a Power Usage Effectiveness (PUE) 'Gold' rating. The PUE rating is the ratio of the power used in the computer equipment itself as a proportion of the total power used including cooling, fans, lighting etc. The gold rating requires a maximum PUE of 1·4 (eg for an IT load of 100kW, the total electrical load will not exceed 140kW) A typical computer room has a PUE rating of 2·0 to 3·0 so meeting the gold standard was a challenge. This 1·4 PUE rating was met under test conditions at the building commissioning stage but at present is not being reached as the room is only running at 10% of design capacity.
The building is a single storey 'cube' with a shallow pitched roof. It is designed to house 52 data racks in four aisles of 13. The data room links to the old computer suite which now houses the uninterruptible power supply (UPS) units.
The original intention was to construct the walls using straw bales. These would have been assembled on a local farm with compressed straw being sandwiched in a timber frame but unfortunately the timber panels proved too large to get into the confined site available. BREEAM requirements meant that the choice of materials were important so the external elevations of the building were finished in a natural lime mortar.
Most new buildings in this country need to achieve high insulation levels to minimise energy use for heating. In this case loss of heat through the structure (for most of the year) was an advantage and we were pleased that the Building Control Officer relaxed the regulations and allowed the new room to be constructed with no insulation in the walls, floor or roof.
The main consideration with any computer room is removing heat from the servers in the racks. Newer servers generate ever-increasing heat loads per rack and the removal of this heat in a sustainable way was the primary consideration in the design of the mechanical and electrical services. Also at this time a large warehouse to store geological cores was designed and constructed at Keyworth. This presented the opportunity to recycle the waste heat generated from the computer room to heat the core store via an underfloor heating system which is maintained at 17°C. The reuse of this waste heat has provided a 22% CO2 reduction compared with no heat reuse.
Mechanical plant was selected to be the most efficient available for the size of the building. This included a Turbocor chiller that provides the cooling capacity and a UPS with 98% efficiency. The current cooling capacity of 300kW will service the 26 racks installed. When the two remaining aisles/26 racks are installed some additional plant will be needed but this can be installed with minimum disruption.
The building was completed in Summer 2010 and the computers transferred in September.
The building achieved BREEAM 'Excellent' standard for both the design and construction phases and was also awarded Building Research Establishment 'Building 4 Change' award (one of 14 nationally) as the first being assessed under BREEAM Data Centres 2010.
The building was also named winner of the Building Research Establishment (BRE) Data Centre Award for 2012.