Balmain Hospital – ENERMAX SMARTcube Gas Boosted system


Inner Sydney suburban hospital requiring replacement of 30-year-old water heating plant to supply wards, kitchen and general amenities. Due to its age and condition, concerns existed that it could not support ongoing demands of the facility. Upgrading of the plant was therefore required to ensure consistent and reliable supply of hygienic hot water, and to deliver energy reduction and plant durability.

Essential that the system replacement be conducted with minimal disruption to hot water supply.

System Requirements:

Reliable, uninterrupted hot water delivery to the facility. Must be capable of delivering a peak of 8,110L per hour at 65°C. Energy efficiency should be superior to the existing system, and ongoing maintenance requirements minimised.

Original System:

Outdated technology with a 30-year-old gravity-fed DHW system comprising:

  • 2 x conventional gas boilers (one of which was decommissioned due to failure)
  • 1 x 5,000L copper storage tank

Being gravity fed, this plant was located over two levels – storage tank on level 6 (top level), with boilers on level 5.

ENERMAX System Solution:

  • 2 x ENERMAX SMARTcube unpressurised 500L tanks – SC500, comprising dual stainless-steel coils for hygienic hot water and high flow rate capability.
  • 6 x Noritz 28L/min Internal Condensing Commercial Continuous Flow gas boosters, 220MJ/Hr at 84.5% thermal efficiency. Completed with fluing including through-wall terminations for external discharge as per AS/NZS5601.
  • 2 x Grundfos pumps for the system primary loop function.

Future capability for Solar PV supplementary energy supply – as ENERMAX SMARTcube is easily converted to take directly up to 2kW of DC Solar PV input per tank, through simple fitting the ROSC20 solar module and its connection to a Solar panel array if installed.

System Performance:

  • Footprint – total footprint is significantly less than the combined original system and the complete system is in one location, within the same plant room.
  • Delivery – consistently delivering up to 8,200L at 65°C in the first hour and recovering 7,200L per hour thereafter at 65°C.

  • Hygienic heated water supply – the unique ENERMAX SMARTcube design separates water being heated for consumption from the heat exchange water in the tank, passing it through dedicated 316 Stainless Steel coils for hygienic supply.

  • Energy Reduction – reduced energy usage, as system thermal efficiency is improved from estimated 70% (original system) to 84.5%.

  • Installation changeover/retrofit disruption – minimal disruption to hot water supply, full supply returned with 4 hours of plant changeover/installation.

  • Durability – the primary loop within the ENERMAX system is unpressurised, reducing load and wear on the Commercial Continuous Flow gas units for improved durability and less ongoing maintenance.

  • Low NOx gas burners of the 28L Commercial Condensing Gas Continuous Flow units deliver improved emissions and air quality.


This ENERMAX solution provides reliable hygienic heated water for this health care installation. The system is superior in operation to that it replaces and delivers the high hot water volume required at lower energy cost. The unique design not only ensures hygienic hot water, but improved long term durability at lower maintenance costs. The ability to supplement the energy requirements with Solar PV at a future time if desired, is easily accommodated through the ENERMAX SMARTcube design.