When it came to selecting a water heating system for the Vogue apartment development in South Yarra, Hickory Group construction manager, George Abraham, said there was a lot to consider.
Working with engineering consultants, MacCormack Associates, Abraham said the team assessed three options before choosing the instantaneous electric option.
“There will always be a project expense for supplying hot water to a large number of units, but the installation and ongoing costs can be minimised with the appropriate choice of heating system,” he said.
“The main options for supplying hot water to apartments in medium or high-density developments are a centralised gas-fired water heating system or instantaneous heating systems installed at, or very near, the point of use.”
The Vogue South Yarra project, which was completed on time and within budget, is a mixed development of retail outlets and 498 residential apartments in a 31 storey tower.
One option considered for the project was a centralised system, in which large boilers and storage tanks are installed along with pipework to the apartments.
Where a development has several hundred apartments, centralised hot water systems require multiple boilers and all pipework must be duplicated for the hot and cold supply.
Each floor also requires two sets of pressure balancing valves.
The hot water pipes to each apartment are often referred to as ‘dead-legs,’ meaning that the water often cools down while waiting to be drawn off.
This system also means a lot of upfront costs for a dedicated plant room, large commercial gas boilers, hot water storage tanks, circulating pumps, and the reticulation pipe work.
The alternative to a centralised system is ‘instantaneous’ heating at the point of use.
In this scenario, a cold water feed is run to each apartment and a water heater installed so that the length of any ‘dead leg’ is significantly minimised.
Abraham said there are many advantages to stand-alone instantaneous hot water units which is why the team chose Stiebel Eltron DEL units.
“Water is only heated at the time of use and energy is not wasted in maintaining a stored volume of hot water,” he said.
“With the heating units located closer to the point-of-use, pipe runs are shorter and less water is wasted by the user while waiting for hot water to arrive at the outlet.
“If only a cold-water feed has to be provided, the commissioning engineer only needs to configure the pressure balance once on each floor using pressure valves and pumps,” he said.
“The cold water feed can be run to each apartment and then connected to the water heater.”
The director of MacCormack Associates Consultants, Alistair Guss, said the work was kept to schedule because the offices and apartments could be completed in stages.
“During construction of the podium levels and tower, groups of apartments were completed and handed over to their owners,” he said.
“This allowed the plumber to work to the builder’s schedule on an apartment by apartment, level by level basis.”
Vogue apartments
