FM MAGAZINE Dec-Jan 2014; ENERGY EFFICIENCY IN ST VINCENT
St Vincent’s has achieved reductions in energy use of around 2.5 million kilowatt hours per annum with a payback of less than six months.
Lighting and air-conditioning were found to represent around 70 to 80 percent of total energy consumption in St Vincent’s Health Australia’s larger hospitals due to the continuous use and strict performance levels. Through the use of a modified energy performance contracting arrangement, St Vincent’s reduced its risk.
Even with these limitations is it possible to find innovative ways to address energy efficiency that generate meaningful reductions at low cost. …resulting in a 16.2 percent average energy saving on the consumption of the variable speed drive.
Hospitals can place some ‘unique’ demands on HVAC not seen in other sectors. For example, certain types of operations (for example, heart transplantation) require the operating theatre to be kept at or below 18 degrees Celsius for extended periods (up to 20 hours) irrespective of time of day or external temperature and humidity levels kept within a two percent bandwidth.
Delivering these kinds of conditions obviously places a heavy load on HVAC systems with attendant spikes in energy consumption. St Vincent’s thus sought to find solutions that could provide a tangible benefit in delivering HVAC energy reductions, but in keeping with the ‘hands off’ low operational impact methodology.
Case Study 3: fine-tuned BMS
The current building management system (BMS) was installed in the early 1990s and, as such, has limited functionality compared to more recent systems. St Vincent’s sought a solution, primarily around HVAC manipulation, that would achieve cost and energy reductions through greater BMS control.
The use of advanced algorithms was seen as one area worth examining. The CSIRO has undertaken much work in developing an algorithm for HVAC control that correlates data from the BMS, energy service providers and the weather bureau to provide a blended approach to setting conditions6.
Factors such as internal conditions, external conditions, off-peak periods and levels of acceptable dissatisfied customers are also used to constantly fine-tune the conditions in the buildings by drifting temperature set points and pressure set points, while anticipating heating and cooling demands. The end result brings better living conditions throughout the building, while reducing energy spending on the HVAC side.
Additionally, through the use of a modified energy performance contracting arrangement, St Vincent’s reduced its risk, in that should the system derive no savings, St Vincent’s does not pay, but any savings are shared.
Another important aspect with this solution is that it pinpoints where the existing set-up is not performing and allows the different parties involved (engineering services, mechanical contractors, BMS contractors and management) to take action having made an educated decision beforehand.
For example, a chilled water valve has been left open on one of the air handling units after a control check. The algorithm would raise an alarm for abnormal energy spending. By the same principle, any energy leakage can be detected and taken care of by the parties involved. Overall, it allows better maintenance of the existing set-up by addressing issues early, which in turn reduces costs.
This was highlighted recently when the charts showed an increase of energy consumption on Sunday 1 September. The software showed the figures, but when it came to what was driving this, no system abnormality could be detected. It took the reflection of one staff member to remind us that it was Father’s Day and occupancy had risen considerably. This confirms that regardless of the technology at work, people are integral to the process.
What has been observed through the assessment of these technologies by St Vincent’s is that it is possible to achieve meaningful energy efficiency outcomes without major building system upgrades.
Measurement and verification are key, particularly when using new or emerging technologies. However, the newest products are not necessarily the best fit simply because they are new. Alternatives may exist that are cheaper but just as effective, particularly on a cost benefit basis.
1. J Daley, C McGannon and J Savage, 2013, ‘Budget pressures on Australian governments’, Grattan Institute, pp 15-16, ISBN: 978-1-925015-31-7.
2. G Banks, 2012, ‘Health costs and policy in an ageing Australia: Health Policy Oration 2008’, Menzies Centre for Health Policy, John Curtin School of Medical Research, ANU, Canberra, 26 June, Productivity Commission, Canberra 2012.
3. Adam Cooper, September 2012 ‘Hospitals failing to tackle increasing energy costs’, The Age newspaper, Melbourne, accessed online 4 September 2013 – www.theage.com.au/victoria/hospitals-failing-to-tackle-increasing-energy-costs-20120912-25su3.html.
4. H Dimoff, May 2013, ‘Reducing Energy Use Can Improve the Fiscal Health of Hospitals Nationwide’, NBBJ Architecture 14 May 2013, accessed online 4 September 2013 – www.nbbj.com/news/2013/5/14/reducing-energy-use-can-improve-the-fiscal-health-of-hospitals-nationwide.
5. Freudenberg Filtration GmBh, 2009, ‘Saving Energy with Viledon Air Filters’, Germany, accessed online 12 September 2013 – www.freudenberg-filter.com/fileadmin/templates/EN_downloads/Energieprospekt_E_4-09.pdf
6. N Durr and P Saiko-Leuthi, 2013 – www.entro-py.com.
Matthew Power is group energy and environment manager of St Vincent’s Health Australia.