Cooling System

Cooling air for the data centre is provided exclusively by three air handler units (AHU), rated at 1,300 cubic meter/minute. Cooling air from the AHUs is supplied under the raised floor from one side of the data centre. Return airflow is through the ceiling registers and ceiling plenum, back to the AHUs as illustrated in Figure 1. The AHU fans have variable frequency drives
(VFD) that are currently controlled by manually adjustable set-points. Chilled water valves are controlled by the supply air temperature set-point. Chilled water is provided by the central chilled water plant.

The chilled water plant is comprised of three 500 RT water-cooled chillers with a combined capacity of 1,500RT, primary and secondary pumps. A building automation system (BAS) monitors and controls the plant. As Figure 1 shows, the facility has conventional air-cooled racks as well as racks with rear-door heat exchangers. This presents an opportunity since the air from contained hot aisle is mixed with the relatively cool air from other areas. This dilutes the return air temperature, making it cooler than it needs to be, and reduces the chilled water return temperature.

Electrical System

The building is served by two main 12 Kilovolt (KV) utility feeders. Two 2,000 Kilowatt (kW) diesel standby generators are provided to power selected critical loads, including the IT load and the mechanical equipment loads serving the IT. An uninterruptable power supply unit (UPS) is provided to supply short term uninterrupted power to the high performance
computational (HPC) equipment. This system is more efficient than a conventional UPS system. A conventional double-conversion UPS system provides uninterrupted power to other loads. Each UPS system is sized for 970 kW.

Question For Writing Assignments On FMT302 Operation and Maintenance of Building Services

(a). With a schematic diagram showing various major components or subsystems for the data centre, illustrate and analyze the operation function of the centralized airconditioning system for the data centre building to minimise the inefficiency and ineffectiveness of the ACMV system.

(b). Examine and analyse the data centre’s operation strategy for energy and environmental sustainability to lower the energy consumption and building greenhouse gas (GHG) / carbon emission. Your analysis should include but not limited to respond to variations in equipment loads, changes in usage pattern, space layout, legislative requirements; maintenance standards and requirements, future developments (where appropriate) and etc.

(c). In a power failure incident of incoming electrical supplies, main incoming which supplying power to the plant room such as chillers, pumps, lighting, ventilation fans, and etc had affected the data centre operations. The trip alarm was triggered and alerted the Building maintenance and IT technicians and supervisors. Propose a Standard Operating Procedure (SOP) for LT incoming power breakdown using a flow chart and formulate a maintenance programme for electrical systems and its implementation.

(d). Chiller and cooling tower are two key sub-systems of the air-conditioning system. In accordance with the relevant codes and regulations, examine and analyse the challenges of implementing and managing the maintenance program of the air-conditioning system which will enhance the performance operation efficiency of the data centre.

You should make reference to a number of relevant FM issues, including legislative requirements; maintenance standards and requirements, future developments (where appropriate); customer service; workplace comfort; and any other issues of concern.