ASB North Wharf – the banking group’s new head office in Auckland’s Wynyard Quarter – is equipped with a state-of-the-art lighting control system that’s helped the building earn numerous energy efficiency and sustainability awards.
Boasting some 18,000m2 of modern, airy office space, the iconic building incorporates significant sustainable design elements, including a giant reflector on the roof to disperse natural light throughout the structure, thereby reducing its dependence on artificial light. To optimise the abundance of natural light, a C-Bus lighting control system – supplied by Schneider Electric – provides artificial lighting only when and where necessary. The modest use of artificial lighting has assisted in earning the building a “five green star rating” from the New Zealand Green Building Council. Auckland systems integrator Intelligent Environments programmed and commissioned the C-Bus system, and general manager Paul Harris says the installation is not only one of the biggest the company has tackled, but also one of the biggest in the country. “It required the programming of more than 2000 DALI ballasts, 500 intelligent sensors and some 160 intelligent light switches.” Intelligent Environments is one of Schneider Electric’s Premium Partner systems integrators, and having used C-Bus many times, says Harris, “we knew its capabilities. We wanted a robust, flexible lighting control system and we were confident about recommending it as the perfect solution for the building’s unique energy requirements. “Because of the amount of natural light being reflected and directed into the building, we incorporated daylight harvesting into our programming. This means lights automatically dim – or switch off altogether – in areas where lux levels are high. Conversely, they only burn at full strength when there is insufficient daylight, such as on heavily overcast days.” C-Bus, he points out, not only provides precision lighting control but also integrates seamlessly with the entire building’s energy systems. “The technology also communicates directly with the structure’s Building Management System (BMS), allowing the lighting to interface with components such as security and HVAC. The HVAC system, for example, takes its lead from the lighting and motion detection technology. The heating or air-conditioning is automatically disabled in meeting rooms where there is no activity.”
Intelligent Environments’ design introduced a number of innovative programming features, including “absence” detection. Absence detection, says Harris, has demonstrated a 10 – 12% energy saving over conventional programming of motion sensors for presence detection. “When programmed for presence detection, motion sensors trigger the lights when someone walks into a room (and possibly the HVAC system) and then switch everything to off when no further movement is sensed , perhaps 15 – 20 minutes after the area is vacated. Although this ensures that lights do not remain on in an empty room, lights are often triggered unnecessarily, say when someone enters briefly to pick up something from their desk. “With absence detection, the user is required to physically switch on the lights (and perhaps trigger the HVAC). If only entering the area briefly, the person may choose not to flip the switch. But if the lights are turned on and the occupant leaves without turning them off, the programming turns them off after a pre-set period. It’s a different programming approach which consistently saves more energy, and which C-Bus’ flexibility accommodates easily.”
Easy to use
The entire system is orchestrated with Schedule Plus software – part of the C-Bus suite. To obtain the full benefit of the C-Bus technology, says Harris, a client needs to be able use it easily. “We created a customised GUI so that the ASB team could monitor current light readings throughout the building as well as make adjustments to different zones to reflect changes in work hours. Holiday schedules as well as various exterior and feature lights – are all adjustable by authorised ASB personnel. The system also has remote access capability, so our company is able to offer the client full support with minimal disruption in the workplace.” One of the key factors in the project success, Harris believes, was Intelligent Environment’s early interaction with the client. “With many commercial projects the specification contains only limited information about the end user’s requirements. The lighting control system is designed and priced to meet the specification, but it may be a long way from meeting the client’s actual needs. “To avoid this issue Intelligent Environments offers consultation services at planning stage at no charge. We believed C-Bus was the best solution for ASB’s needs and took the team to Schneider Electric’s headquarters in Highbrook. This building not only uses the technology but is also specifically designed to demonstrate how it works and the potential benefits.” Intelligent Environments continues to work with the ASB team in the new building, assisting to identify energy-saving opportunities.