*figures have been adjusted for Darling Park's higher hours of occupancy according to PCA's methodology: benchmark factor multiplied by actual annual occupancy hours (4700) divided by average occupancy (2500). This is applied to all except heating and cooling (because of thermal mass storage effects).

This shows that Darling Park 1 is moving slightly away from the best practice benchmark. This, even though the PCA benchmarks are not as stringent as the BOMA guidelines they displaced (BOMA, 1994).

Darling Park Tower 2

Darling Park Tower 2 was also GBR rated by SEDA for 2000, but as it was not fully occupied in that period, the building's owners and managers did not wish the rating to be officially issued. It will be assessed early in 2002 using 2001 data; one would expect that once fully tenanted, its performance would be similar to Tower 1. The 2000 data gathered was:

Darling Park Tower 2: Building Greenhouse Rating by SEDA

*also excluded levels 28 & 29 - Plant, basement, car park levels (7) and forecourt

Tenant Energy Performance

Since opening in 1993, Darling Park Tower 1 has generally had above average occupancy rates. At present there are seven tenants, most occupying several floors. Tenants are seperately metred for lighting and general power, which they pay for directly to their respective electricity suppliers. For common building services (HVAC, lifts, hot water) and common area lighting, they are charged pro rata on the basis of hours of occupancy.

 

Information could be obtained on the energy usage of newspaper publisher, FairFax, the largest single corporate tenant. Fairfax occupies nine floors, several of which operate 24 hrs/7 days. They are a participant in SEDA's Energy Smart Business program, a scheme in which companies agree to energy efficiency milestones which SEDA assists them in achieving. Most of Fairfax's efforts have been focused on improving the energy performance of its production plants (especially the Chullora plant) rather than the Darling Park offices. The reason for this, according to Fairfax management, is that approximately 20 million kWh / per annum is used for the material production of newspapers at Chullora, while only 5.6 million kWh / per annum is used by the Darling Park offices where journalists, editors, advertising staff and the like are housed. Some impressive demand reduction measures have been undertaken at Chullora, such as a de-lamping and lighting control improvement program that has yielded an annual saving of 14,904MJ (or 4,140kWh).

Performance Compared to Benchmark

The 5.6 million kWh/pa at Darling Park is for lighting and office operation. While this is only an approximate figure it is nevertheless instructive to compare it to the PCA best practice benchmarks for Sydney offices, as the following calculation shows.

1. The PCA benchmarks are expressed in MJ. Given that 1 kwh = 3.6 MJ, Fairfax's 5.6 million kWh = 20,160,000 MJ. Dividing this by the space occupied by Fairfax, 17,300 m2, gives a result of 1165 m2.

The PCA benchmark for tenant power is 85MJ/m2 pa and tenant lighting 140MJ/m2 pa which together equal 225MJ/m2 pa.

2. Adjusting the PCA benchmark, which is based on 2500 hours pa occupation to take into account Fairfax's 6487 hours pa. This computes as: 225 X 6487 divided by 2500 = 584.

Therefore the adjusted benchmark for Fairfax is 584 MJ/m2 pa. Fairfax's actual power consumption is approximately 1122 1165 MJ/m2 pa, which is double the benchmark.

Fairfax management are concerned about this poor performance and are currently evaluating appropriate demand management measures within the context of their Energy Smart Business partnership with SEDA. Importantly, the causes have been identified.

 

Causes of High Energy Consumption

1. Lighting switching controls: these do not allow only a few lights to be on at a time (this would be useful for areas and times of low occupancy), nor timed usage, occupant sensing or effective use of daylight perimeter (see above 'lighting'). On some floors all lights are left on 24 hours a day, 7 days a week even though those floors would not be 100% occupied all the time.

2. IT equipment: a large number of machines, most of which are not configured for power management (i.e., powering down when not used for a set period of time) along with work practices of not closing down machines.

3. Supplementary air-conditioning unit (with its own chiller) installed by Fairfax for its dedicated computer rooms.

4. Staff behaviour: As computers and monitors are routinely left on when people finish their shifts, there is no development of a 'demand management' ethos.

Possible Solutions

1. Lighting switching controls: An estimate has been obtained by Fairfax for installation of a time control system and reconfiguration of lighting zones (to create more than the current 3 per floor, plus individual switching for single offices, of which there are many). If this work was carried out, the payback period (from savings on energy bills) would be about three years. Management is considering this in the context of decisions about lease renewal.

2. IT equipment: Advanced power management for PCs is under investigation by the Technical Support department, with a recommendation for trials, staff education and a phased roll-out. One concern is the ten second time delay in powering up which, it is thought, could interfere with editorial production.

3. Supplementary air-conditioning unit: The efficiency of the supplementary air conditioning could be investigated, as well as its interaction with the building's HVAC system.

4. Staff behaviour: A commitment by senior management to creating an environmentally responsible workplace would be a necessary precursor to workplace cultural change, which could be implemented via a significant information and training program, with leadership from organisational 'environmental champions'.