Westfield deploys energy-efficient lighting solution

The retail property group Westfield’s corporate headquarters under the iconic Centrepoint Tower were designed to minimise the use of natural resources, provide a more productive and comfortable workspace for staff and target a 5-star NABERS energy rating and a 6-star Green Star rating.

It was essential that the lighting architecture would meet the project’s green criteria and complement the environmental design ethos of the building. Westfield wanted the lighting system to reduce the energy requirement for lighting as well as enhance the working environment by maximising natural light where possible. Vital to achieving these efficiency goals was the installation of Philips Dynalite specified Digital Addressable Lighting Interface (DALI) technology. The technology is simple to install and commission and monitors and controls lighting within the office environment, which significantly reduces the use of energy. Energy costs are lowered through daylight harvesting and standard controls such as dimming and occupancy sensors. Rather than depend on staff to turn off the lighting, the intuitive DALI system does it.

Each luminaire in the building is individually addressable, which delivers flexibility in control and monitoring. Lights can easily be grouped, ungrouped and regrouped into different control areas without the need to reconfigure any fixed control wiring and redundant lighting can easily be temporarily disabled.

The entire system is centrally monitored through the building management system (BMS), which allows the automatic identification of failed lamps and ballasts. The installation of dimming luminaires around the perimeters of the office enables artificial lighting to be increased or decreased to balance natural light levels. Switching was used in the building core where natural light levels were too low.

To optimise energy efficiency, lighting is fully automated during normal office hours. The lighting control system is interfaced through a Philips Dynalite DDNI-BACnet switching device to the main building management system (BMS). After hours, the BMS assumes global control over the lighting controls - along with HVAC and security systems - and is able to switch off the lighting after a preset time.

Dynalite DPN eight-button user interface panels were installed near the lift areas to allow staff to activate lighting when needed. The DPN panels were installed in the boardroom to allow the selection of preset lighting scenes such as ‘conference’, ‘presentation’ and ‘meeting’. A Philips Dynalite DTK622/RS232 AMX interface allows control of the audiovisual systems through the system and also allows supervision of the lighting through the AMX controls.

The Philips Dynalite’s Mapview software, which is accessed through a head-end computer in the security area, helps monitor, manage and - when required - reconfigure to meet changing needs within the building over time. The solution helped Westfield achieve both a 5-star NABERS Energy rating and a 6-star Green Star rating. The lighting system allows the building to make intelligent decisions about the optimum delivery of light. Lighting controls can switch lights off when no one is around, automatically adjust lighting levels based on the amount of natural daylight in the space and turn off or dim lights, based on the daily cycle of the office. The perfect control of the lighting means that the least possible amount of light is supplied when needed. Together with the many energy-efficient building and services designs that have been included in this project, the lighting control system has helped reduce energy consumption by 30%.

Products and technology used

In total, 300 DALI fittings were installed in the 32,000 m² space. A combination of fluorescents and LEDs was used, with 64 channels of switching controlled through the Dynalite DMRC210 relay fixture couplers and the remaining 236 channels of dimming controlled through Philips’ Dynalite DDBC300-DALI ballast controllers.

A single lighting control network was used, with the Dynalite DDNG485 network bridges used to connect each floor’s subnetwork into the sophisticated Philips Dynalite peer-to-peer communications Dynet RS485 trunk network. A combination of Dynalite DUS804C and DUS804C-UP universal sensors was used for both lux levels and presence sensing. The DUS804C-UP sensors, which use ultrasonics rather than infrared and are more sensitive than the standard DUS804C, were installed in the core areas of the building, which reduced the number of sensors required.