Ducted and split air conditioning units from Daikin Australia were installed at the luxurious Saffire Freycinet Resort in Tasmania, achieving both aesthetic and performance objectives sought by the architects.
Located at the edge of one of Australia’s most celebrated national parks, the luxurious Saffire Freycinet resort has been designed to achieve the ultimate in amenity, privacy and relaxation for its limited number of guests. Overlooking Coles Bay and the pink and red granite peaks of the Hazards mountain range, the Saffire Freycinet resort takes full advantage of its spectacular location while delivering an exceptional level of amenity to its guests. The luxury hotel accommodates just twenty couples at any one time.
According to its award-winning Tasmanian architects, Circa Morris-Nunn, the resort was imagined as an iconic project to redefine tourism in Tasmania. After winning the Hotel of the Year title at the World Architecture News Awards (UK) in 2011, the property has consistently featured in the top hotels lists of international travel magazines.
Developed on the site of a disused caravan park, the Saffire Freycinet project was as much about repairing the site and interpreting its unique qualities as it was about creating a space from which it could be experienced, says Circa Morris-Nunn. The design of the resort is conceptually organic and reflects the surrounding environment by evoking a connection to the sea and the rugged nature of the mountains that dominate the landscape. This theme is evident in the elegant, stingray shape of the main building that houses the resort’s reception, dining spaces, guest lounges, bar and health spa.
The building’s roof, made from curved Tasmanian wood beams, features a ribbed structure with ply overlay that forms a smooth underlay for the Polymea membrane. At the southern façade under the stingray’s wings is a three-storey high wall of glass that allows guests to take in an uninterrupted panorama of Coles Bay, the Hazards and the peninsula beyond. Luxurious guest suites placed in a wave-like configuration beyond the main building provide for three levels of accommodation – deluxe, luxury and premium. Each suite ranges in size from 80m² to 140m² and has been designed to maximise the breath-taking views with expansive glazing throughout, while maintaining a high level of privacy from neighbouring suites.
Among a number of requirements inherent in the challenging project brief was the delivery of luxurious amenity across all levels of the project. While this is immediately visible through the use of high-end furnishings and finishes that reflect the landscape and contribute to a relaxed ambience, much of what makes Saffire Freycinet resort so luxurious remains concealed. This includes the provision of an indoor environment quality - both in the different spaces of the main building as well as the guest suites - that maintains a high level of comfort without impacting the aesthetics of these spaces.
The architectural form of the main building, as well as its varying uses and elements such as pools and ponds, presented several challenges for the project’s building services and ESD consultants, Wood & Grieve Engineers. Among them was the concealment of services while ensuring thermal conditions were maintained. Grant Holman, Director with Wood & Grieve explained that the unusual form together with the large extent of south-facing glazing meant that a significant amount of design effort was invested into the final solution.
This required a considerable amount of collaboration between the engineer and the architect to achieve the desired aesthetic outcome, while ensuring that the performance of the systems was not affected. The curved shape and the roof profile meant that the architect was unwilling to have any services penetrate through the roof or affect the visual aesthetic for the guests. This required an unusual configuration and layout of services across the three levels of the main building.
A main plant room was located on the ground floor to house the three 3-pipe Daikin VRV heat recovery ducted units, a small number of single split units (to serve back-of-house areas) and concealed fan coils serving the various guest spaces. A standalone plant room, located in the tail-end of the building near the main entrance, was designed to conceal all condenser units and minimise issues of frost and de-icing. All exhaust discharges were grouped in another area away from view, avoiding the need to penetrate the roof.
Brett James, divisional manager with mechanical services contractor Degree C commented that there were 34 indoor systems across ducted, ceiling cassette, floor mounted and high wall indoor units. While the ducted systems served the public spaces, the individual indoor heads served back-of-house rooms.
According to James, a common return air path was incorporated into an architecturally designed, perforated metal funnel located centrally at ceiling level within the first floor function area. This feature acts as a return air catchment point, where the air is then ducted within the ground floor ceiling space back to the ground floor plant room.
The floor-to-ceiling glazing that delivered the resort’s most panoramic view of the bay and mountains was one of the many spaces within the main building that created unique challenges for Wood & Grieve. Unable to deliver air within close proximity of the glazing, computer modelling was conducted to avoid condensation from forming on the glass, while achieving the required indoor comfort levels. Wood & Grieve worked closely with the diffuser manufacturer to find a solution that would achieve adequate throw without creating a draft, particularly in areas where guests were seated. Careful diffuser placement, good glazing performance and correct discharge velocity were all critical to achieving the desired outcomes.
In the guest lounges and dining spaces, conditioned air is delivered via low level grilles located in the joinery unit kick spaces as well as discreet wall grilles. Other areas are served by overhead delivery via grilles incorporated into the architecture. According to Holman, although the design temperatures within these spaces allow for typical comfort conditions, given some systems use underfloor delivery, the off coil air temperature had to be managed to ensure the VRV system didn’t drive it too low in cooling.
Considering the building’s multiple levels and uses, the control of economy cycles was carefully selected so as to manage the impact of pressurisation across the space. The main challenges came in balancing the airside of the systems in terms of overall pressurisation, together with the design of a common economy cycle for the main building. Interfaces with the individual systems’ heating and cooling signals and space temperatures were also a challenge.
James said the control of the mechanical services required the use of both a Daikin intelligent touch (iTouch) controller, and a separate DDC (direct digital control) control system. Since there was a requirement to control fresh air, return air, de-stratification temperature control and economy cycle control for the ducted systems, a DDC control system was incorporated into the overall building control.
Five separate 3-pipe Daikin VRV heat recovery systems have been used to service the twenty luxurious guest suites. Since concealment of services in these spaces was an important requirement, each of these systems connected to 45 concealed, floor-mounted indoor units located across the suites. Often located in bedroom areas, these boxes were acoustically treated to prevent the gurgling sounds that VRV systems sometimes emit.
Fan coil units, mostly of the vertical bulkhead unit type, were concealed within the walls and upstands dividing the spaces. The condenser units were located in external service pods, concealed from view yet readily accessible for maintenance without impacting on guest amenity or privacy. Refrigeration piping and associated electrical cabling serving each suite was installed underground, by enclosing and sealing each 3-pipe VRV piping system within 150mm diameter PVC piping conduits.
Another challenge was in ensuring the air delivery did not create a draft in the guest suites. They worked with the diffuser manufacturer to resolve some of the low level delivery systems. While the design temperature allows for standard comfort conditions in each suite, the systems also offer the flexibility to be programmed to suit guest preferences using the individual temperature control.
According to Holman, the total capacity of all VRV systems across the resort is around 370kW including spare capacity to allow for de-rating under defrost cycle. He says the specification of Daikin systems by Wood & Grieve largely came about due to the limited energy sources available at the site. They worked with Daikin in terms of capacity and location, as well as protection of the condensers to manage any reduced capacity during winter de-ice.
The ability to remote diagnose faults with these systems was also deemed an important feature, and meant maintenance technicians could attend the site already armed with any required part. This was particularly important given the remote location of the resort. Holman says considerable effort was put into the commissioning of the systems by the mechanical contractor, so as to ensure they operated as expected over the full operation range.
According to James, the commissioning of the Daikin VRV systems was undertaken by the firm’s own experienced technicians, who also drew on the experience of Daikin’s Jeff Slater to finalise the commissioning process.
Since the completion of the Saffire Freycinet resort in September 2010, the entire air conditioning and exhaust system is reported to have operated as designed and been generally free of any issues.
Image: The lounge at the Saffire Freycinet resort