81 percent reduction in energy use achieved
In mid-2012, an LED lighting upgrade of NAB House’s two fire stairs was undertaken, achieving an 81 percent reduction in energy use.
Owned by AMP Capital Investors and Brookfield Office Properties, NAB House is an A-grade commercial office tower featuring 29 levels of office accommodation, ground floor banking, a café and a basement car park for 219 vehicles. Between 2008 and 2011, a major upgrade program was undertaken, including central plant upgrades, a new on-floor air distribution system, a new building management control system and architectural upgrades, while maintaining full occupancy. The building achieved a five-star NABERS Energy rating in 2011 and achieved another five-star rating in July 2012.
In mid-2012, an LED lighting upgrade of the building’s two fire stairs was undertaken. The existing emergency lighting in the fire stairs was twin (18-watt and a mixture of 32-watt and 36-watt) fluorescent tube lighting with magnetic ballasts that were operating 24 hours a day and had no controls. The retrofit, for which enLighten Australia was awarded the supply and install contract, resulted in the replacement of the existing 184 fluorescent fittings (368 tubes) within the fire stairs with 184 emergency Chamaeleon lights, which produced the same light output levels. A combination of 10 chip ceiling and wall mounted emergency Chamaeleon fittings were used. The capital cost was $58,515 including installation.
Fire stair meter data supplied by the building management indicated an average 81 percent reduction in lighting electricity usage across sub-metered lighting circuit covering fire stairs one and two. The pre-installation consumption figure of 4587 kilowatts per hour (for May 2012) was reduced to 910 kilowatts per hour following the installation of the new lights.
The LED retrofit project ROI is projected as 3.3 years, inclusive of electricity and maintenance savings. Maintenance savings were calculated using conservative estimates for maintenance access, lamp and control component replacement costs, disposal costs and emergency battery costs.