Company: Airedale Intl. South Africa
Customer: Vodacom Pty. Ltd.
Completion: March 2014
• 2 or 3 x 40-95 kW SmartCool™ dual-circuit air-cooled precision air conditioning (PAC) units;
• 1 or 2 x 60-95 kW condensers/dry coolers;
• Three-stage indirect free cooling control achieved by adjusting fan speed, pump speed, and control valve, supplemented by DX cooling where necessary;
• Optimized head pressure control — the condensing pressure set point modulates to maintain the most energy-efficient system operating point depending upon ambient temperature and room load;
• Constant pressure control; and
• For comfort, and to prevent the ingress of unfiltered fresh air, a return air plenum air port above each air conditioning unit that supplies one air change per hour (ACH) of filtered fresh air.
Objective: To meet the increasing demand on its data center applications, Vodacom required a solution that would allow it to quickly roll out additional facilities without the time, high cost, logistical barriers associated with new builds, or constraints of retrofitting facilities in existing buildings. Vodacom was also keen to maximize energy savings.
Work Completed: Airedale came up with an innovative hybrid data center cooling plant. Each modular data center consists of either a single 64m² module equipped with 2 x 40, 65, 75, or 92 kW free cooling SmartCool™ downflow PAC units, or two 128m² modules containing 3 x 95 kW SmartCool™ units deployed in a N+1 configuration. To capitalize on free cooling opportunities, the SmartCool™ units are supplemented by an indirect air free-cooling circuit connected to a roof-mounted hybrid condenser and dry cooler system. Inverter-driven run/standby pumps are positioned in weatherproof housing with individual isolation valves and isolators on fans and pumps, and a differential pressure sensor for each pump, thereby delivering the precise capacity match.
Quote: “Airedale delivered with speed and urgency, and the quality of its cutting-edge air conditioning plant designs will make a major contribution to Vodacom’s strategy. The energy efficiency of the modular data facilities fully complements Vodacom program to reduce the group’s overall carbon footprint.” — Fred R. Weber, senior specialist, Vodacom Technical Facilities Division
Publication date: 8/11/2014