University Of Nottingham 2

The University of Nottingham’s state-of-the-art Data Centre opened in 2006. It incorporated the very newest features and industry best-practices at the time including:
• Hot Aisle/Cold Aisle rack configuration
   with N+1 air conditioning,
• Fire Cell with IG55 Gas Fire
   Suppression,
• N+1 room uninterruptible power supply
   units with standby generator,
• Resilient power and network
   configuration,
• Remote access KVM, service
   monitoring, environment monitoring,
   CCTV and card access control,
• An equipment preparation room
   outside the production area.

Best practice, however, moves on and the University has continued to review the facility which has resulted in;
• Individual receptacle power metering in
   Hosting Area - installed in 2008,
• Free-air-cooling, using conditioned
   ambient air from outside to cool the
   servers - installed in 2009,
• Rack based power metering in
   Production Area - installed in 2011.

In 2010, it was identified that air circulation could be further improved. Air was being delivered to and removed from the equipment space with no physical separation. The result was inefficient airflow and the mixing of the hot server ‘exhaust’ air with cool air from the cold aisle. This was increasing the server inlet temperature and making the cooling system work harder than necessary.

The AIT Partnership Group Ltd designed a containment system for the Data Centre to keep the incoming cool air and the hot ‘exhaust’ air physically separated. Air containment systems are relatively cheap to implement. The design of the room is two rows of racks, back to back sharing a common hot aisle; this is why a hot-aisle separation system (HASS) was utilised to provide the necessary air flow separation between incoming and exhaust air flows.

The HASS consists of vertical panels fixed to the full height server cabinets on either side, with cupboard doors on the cross aisles and double sliding doors on the end of the hot aisle. The is ducted to the AC units so that the hot ‘exhaust’ air from the server cabinets is captured and efficiently extracted.

As is typical for Data Centres, equipment is continuously updated and moved, often leaving blank spaces in the server racks where old equipment had been removed. Measures were therefore also taken to avoid loss of cool air by fitting blanking plates in these gaps, again to keep the incoming cool air and the hot ‘exhaust’ air physically separated.