The 2014 Preloved Buildings Conference, held in Brisbane by the Australian Institute of Refrigeration, Air-conditioning and Heating, provided an oppotunity for the sharing of experiences and solutions
Existing buildings may impose constraints on the HVAC designers who work on them, but these very limitations also offer opportunities for novel solutions to be applied.
This was one of the recurring themes of the Preloved Buildings Conference 2014, held recently in Brisbane and hosted by AIRAH, the Australian Institute of Refrigeration, Air Conditioning and Heating, which featured a programme of 20 presenters delivering 14 hours of content over two days.
AIRAH president Nathan Groenhout, M.AIRAH, opened the conference by saying the value of the event lay in the sharing of stories – both good and bad – and discussing the many complex issues surrounding existing buildings, from the simple (renovate or detonate?) to overcoming the problem of split incentives for landlords and tenants.
Professor David Cropley from the University of South Australia set the tone by posing the question, “Is constraint the enemy of creativity?” By discussing the virtues of examining an issue from a holistic perspective, Dr Cropley said that a project’s limitations can help redefine a problem, leading to a diversity of solutions.
In what proved to be the conference’s most popular presentation, Dr Paul Bannister, M.AIRAH, demonstrated how recent advances in building simulation models have made it possible to test a number of common building tuning strategies, and predict potential energy savings.
Bannister’s presentation explored the use of an IES simulation model to assess the effects of a number of common control algorithm adjustments.
“Combined scenarios are used to show that the difference between best practice and poor control can range as high as 50 to 90 per cent,” said Mr Bannister, “demonstrating the fundamental importance of control.”
Arup mechanical engineer Malin Lindblad, App. AIRAH, used a case study of Yarra Valley Water (YVW) Mitcham’s recent refurbishment to demonstrate the opportunities to improve performance of B and C-grade buildings. The building’s location in suburbia was point of difference from many discussed at the conference. The YVW upgrade included a full refurbishment of the office spaces and a complete replacement of the building services to include a standalone tri-generation system.
Mechanical services challenges
Ken Gurcan Erbas, M.AIRAH, drew on 32 years’ experience in mechanical services design to deliver his presentation Mechanical Services Challenges in Pre-loved Buildings.
Mr Erbas provided examples of post-occupancy problems and successes in refurbishing and retrofitting mechanical services into existing buildings.
“The mechanical challenges in pre-loved buildings are not limited to mechanical services,” said Mr Erbas.
“Quite often it is the managing contractor and subcontractor that takes on significant risk associated with the installation and commissioning of HVAC systems into buildings that were not designed to originally accommodate such systems.”
Erbas says that in these instances the understanding of the existing building and appropriate design constraints has a large impact on the success of the HVAC system during operation.
Small council, big vision
GeoExchange managing director Yale Carden, M.AIRAH, presented on the Riverina Highlands Building Energy Efficiency Project, which transformed an early 1980s building with high energy and maintenance requirements into an energy-efficient facility.
The project included lighting and insulation upgrades, solar PV, power factor correction, metering optimisation and the retrofit of a geoexchange heating and cooling system to replace the original air-sourced central chiller and duct heaters.
The geoexchange system consisted of a vertical closed-loop ground heat exchanger (GHX) of 35 boreholes to a depth of 92 m each and 26 water-to-air ground-source heat pumps (GSHPs) with variable-speed compressor, fan and pumping. The GSHPs were distributed through the building to provide local zone control and operation.
Preliminary results to date are a 58 per cent annual reduction of more than AU$213,000 for both energy and maintenance, and an astonishing reduction in maximum electrical demand of 75 per cent.
The takeaway message
Each of the conference’s 60-plus delegates left the venue with their own version of wisdom accumulated and lessons learned For conference committee member Mark Jacobson, M.AIRAH, the lessons related to building commissioning and tuning.
“Without this approach, we end up with modern but inefficient systems,” said Mr Jacobson.
“Communication across all levels of the design, build, construction and commissioning process will deliver far superior building than those approached with a traditional method.”
For more information go to www.airah.org.au/preloved2014