Mechanical services is rarely the focus of a successful hotel, its all about the customer- facing facilities such as bedrooms, fittings and services that attract all the attention.
Not surprisingly that is where money is spent so getting capital for mechanical services is never easy even at a landmark hotel like the Four Seasons in Sydney.
Built in 1981, the Four Seasons Hotel in Sydney has been a long standing attraction for visitors to Australia. Its popularity has little to do with back-of-house facilities which is why it was a challenge for the hotel's operations director to convince the management team to allocate at least $2 million for a HVAC upgrade.
This included replacement of the hotel’s two chillers and two condensing boilers, installation of energy meters, a new BMS and condenser water system and new cooling towers.
To secure funding the solution came in the form of a Build, Own, Operate and Transfer (BOOT) scheme that included purpose-built energy efficient equipment and systems.
The 12-year contract included the design and delivery of a facility upgrade, including the installation of two 900kW Quantum chillers, and ongoing operation with full equipment warranty, delivering 100% operational availability and guaranteed energy savings to the client.
The upgrade equipment included two 900kW Quantum Chillers utilizing magnetic bearing, oil-free Turbocor compressors. The two chillers were reportedly the world’s first magnetic bearing screw chillers of this capacity and length to be loaded via a goods lift.
Both chillers were designed with a vessel length of only 1.9m, with typical equivalent chillers taking up a length of 2.4m.
OEM-trained ENGIE technicians assembled the equipment, which was transported 35 floors up to the plant room via the goods lift. Due to their compact size costly and disruptive craneage was avoided.
Moreover, heat recovery from the chillers via the condenser water loop was used to pre-heat feedwater to the Domestic Hot Water system.
This reduces gas consumption of the boilers, as well as electricity consumption of the cooling tower fans.
There were two Rendamax fully condensing boilers for Heating Hot Water and Domestic Hot Water used asthe two systems are controlled at independent temperature set points for maximum efficiency.
At the same time, Kamstrup Ultrasonic Thermal Energy Meters were used to monitor, control and measure secondary energy demand and consumption of the hotel’s chilled water, heating hot water, domestic hot water and heat recovery.
Existing fiberglass cooling towers were refurbished with all new fill and fans.
Side stream filtration was installed on the condenser water system to minimize the amount of chemicals required. The entire building BMS was upgraded including central plant optimization and energy management system.
The hotel saved 23% off its electricity bill after the first two months of operating the new plant room.
Once system optimisation was complete (currently five months into a 12-month process), the team expects 26% annual energy savings on electricity and 16% on gas. The ENGIE Services team, in collaboration with Quantum design engineers in Germany developed new generation, high efficiency compact chillers for the retrofit market where cranage would normally add significant costs to a project.
The chiller components were specifically designed to fit the goods lift size and weight limitations at the Four Seasons Hotel, saving a huge cost for cranage in Sydney’s CBD.
More importantly, the innovative chiller design allowed the evaporator and condenser vessels to be transported in the lift, without the need for split vessels, removing the risk of costly repairs for leaking gaskets during the life of the chillers.