2 Freshwater Place’s lighting cost reduction strategy
KOK LIM NG, engineering services manager at Jones Lang LaSalle Australia, discusses the lighting strategy of 2 Freshwater Place in Melbourne that enabled the building to converted its 2.5 Star NABERS Energy Rating into a 4.5 Star rating.
2 Freshwater Place, a 55,000-square metre office building in Melbourne, Australia, was built in 2003/2004 and occupied in 2005. The building has achieved a 4.5 Star NABERS Energy Rating unassisted (zero percent Green Power) for the second consecutive year and a 3.5 Star NABERS Water Rating.
The nearby Twenty8 Freshwater Place is 34,000 square metres and has achieved a 5 Star NABERS Energy Rating unassisted (zero percent Green Power) one and a half years later after the defect liability period (DLP) and a 4.5 Star NABERS Water Rating. This was a great achievement for Twenty8 Freshwater Place, considering the building was only designed for a 4.5 Star NABERS Energy Rating.
2 Freshwater Place was built to achieve the highest efficiency in both energy and water in order to reflect the quality of a premium grade building. Unfortunately, the building did not meet the performance target after the DLP. Various efforts were initiated to patch up the shortfall.
The lighting strategy for the building was one of the effective actions taken that formed part of the process of converting its 2.5 Star NABERS Energy Rating into a 4.5 Star NABERS Energy Rating. It also demonstrates part of the effort that can be contributed towards reducing a building’s carbon footprint. This can be achieved at a very minimal cost, while at the same time maintaining the quality of the services provided to the building.
AUDIT BEFORE TAKING ACTION
The key processes of the first stage of the lighting strategy at 2 Freshwater Place involved auditing and the compilation of a report for assessment, taking action and collecting results, and finally reassessment for confirmation.
The building was first divided into the two main categories of lighting that exist in any commercial building:
- office lighting/tenancy lighting, and
- common area lighting/base building lighting.
The base building lighting was then further segregated into two different groups of action:
- a grey area that included plant rooms, service riser, goods lift lobby, roof top, loading dock, compactor room, service corridor, stores and all other service/utility rooms, and
- a key area including all main foyers, tenancy lift lobbies, the main building perimeter, the lifts, the feature lighting and the toilets.
EASY WAY TO REDUCE LIGHTING COSTS
Cost is always a major concern when it comes to formulating a lighting strategy; however, there are many environmentally friendly ways to reduce the cost of lighting that do not involve lamp replacement.
For instance, one way is to remove excess lamps when light levels are greater than needed. This can be easily achieved throughout all the grey areas and potentially in some of the key areas.
Another way is to reprogram existing lighting automation. Commercial towers usually have a lighting automation system installed during the construction stage. It’s possible to implement a lighting control strategy through reprogramming using a lighting automation system by:
- matching up the building operation schedule and the after-hours schedule
- rescheduling the grey areas so that they have the lowest possible operational hours
- reprogramming the key areas so as to make full use of natural lighting, possibly using photo electric sensors in some areas
- reprogramming the key areas that are unable to use natural light via existing sensors and timers to shut down the lights when not required, and
- reprogramming existing motion sensors and incorporating them with a timer to ensure that all lighting turns off when a floor is not occupied after hours.
2 Freshwater Place’s lighting control system includes different automation strategies for external, concierge, car park, podium, event day, special days, loading dock and back of house switching, network state, tower public areas levels 8 to 14, tower public areas levels 15 to 20, tower public areas level 21 to 27, tower public areas levels 28 to 32, tower public areas levels 33 to 36 and Earth Hour, among others.
The first stage of the lighting strategy for 2 Freshwater Place was very effective. It has achieved a monthly average saving of 18,000 kilowatts per hour – 22 percent down compared to the original monthly consumption.
REVIEWING AND REPLACING LAMPS
In the second stage of the building’s lighting strategy, all possible retrofits or replacement of lighting were reviewed. A few common upgrades include:
- replacing lift cars’ 50-watt halogen dichroic lamps with 11-watt compact fluorescent lights
- replacing 50-watt halogen dichroic lamps with LED lamps (three-watt to nine-watt, depending on ceiling height) and with 20-watt halogen dichroic lamps, if LED lamps are not suitable
- replacing 10-watt exit and emergency lights with one-watt LED exit and emergency lights
- progressively replacing two 36-watt fluorescent stairwell lights with 26.3-watt LED lights
- progressively replacing two 35-watt fluorescent car park lights with 26.3-watt LED lights, and
- installing motion detectors/timers in all possible grey areas.
The outcome of the second stage of the lighting strategy for 2 Freshwater Place also proved successful. Power consumption was reduced by more than 50 percent consistently.
The building’s lighting strategy also indirectly reduced the power consumption of the HVAC system in the base building. The main reason for this was that the lighting strategy reduced the massive heat load in the base building, thereby relieving the HVAC system’s load.
PASSING ON THE KNOWLEDGE GAINED
The NABERS Energy Rating was one of the tools used to measure the achievements at 2 Freshwater Place. The continuous reduction of energy consumption has confirmed the success of all the strategies conducted, which included a major reduction in HVAC energy usage. An average of 35 percent in total power consumption has been registered.
Through this simple process, 2 Freshwater Place has converted its 2.5 Star NABERS Energy Rating into a 4.5 Star NABERS Energy Rating. The learning curve from 2 Freshwater Place subsequently had a massive impact on the design and development of Twenty8 Freshwater Place, which was occupied in 2009 and achieved a 5 Star NABERS Energy Rating one and a half years after the DLP.