Northrop

16 Giffnock Avenue, Macquarie Park is a 11,500m² commercial office building owned Stockland Properties and managed by CBRE. Northrop was engaged to complete an energy audit in-line with the ASHRAE level 2 audit guidelines and develop a building improvement plant that would outline practical and cost-effective improvements to progress the building towards the client’s target of a minimum of 4 star, targeting 4.5-star NABERS Base Building rating. The energy audit findings were also used as part of Stocklands Energy Efficiency Opportunities (EEO) reporting requirements.

As part of the first stage of works Northrop completed a review of the plant installed (mechanical, electrical and hydraulic) on site, the building envelope and analysed the sub metering data obtained from the building’s EMS. Analysis of the sub metering data included items such as:

• Energy trends - comparing monthly energy usage of consecutive years to verify the result of any works previously undertaken or highlight any trends due to aging or failing plant.
• External factors affecting energy usage including cooling degree days and heating degrees per month versus monthly energy consumption.
• Peak energy demand - comparing against external factors that can affect the peak energy use such as external temperature.
• Time of day use - comparing peak, shoulder and off-peak usage over different months and years to identify any trends.
• Detailed analysis of selected weeks (particularly with reference to occupied hours), base line energy usage outside of normal hours and on public holidays.
• Break down of site energy consumption into different services to compare each service and identify where the best gains can be made.

As part of the above analysis a number of items were discovered:

• The extent of scheduling on the existing BMS was a 7-day timer. This was resulting in wasted energy use due to extended warm up and cool down periods in the morning and non-required operation on public holidays. As an example, the peak electricity demand for the site during January 2011 was on the 26^th, a public holiday.
• A regular spike in energy consumption outside of hours was noticed to occur at 9:30PM to midnight every Tuesday night, with this spike tracked back to a single tenancy through the sub metering data.
• Two of the floors had higher base loads compared to the rest of the floors (significantly higher). It was discovered that there was fault on the fire system causing the supply fans (part of the smoke control system) to run throughout the night (24/7) operation, when they were not required.

Following the energy audit and building improvement plan, Northrop was engaged to design, document and manage the upgrade of the BMS as part of the first stage of building improvement works. The BMS installation was completed in July 2014, with the first quarterly tuning report from the contractor showing an improvement from a 1-star NABERS base building rating to around 2.5 stars, with further tuning still to be completed (N.B. the only upgrade was the BMS, all other existing aging plant remains to be replaced).