HydroHeat was engaged by AG Coombes to supply hot water heating requirements to a retail location at 222 Bourke St in Melbourne's central business district. The heating system was to replace two existing atmospheric type boiler heaters which had reached their end of life, hence the new system needed to be retro installed to the existing rooftop plant.

The HydroHeat system consisted of a bank of 4 x BAXI Power HT 150kW condensing type boilers, supplied and commissioned by HydroHeat in conjunction with AG Coombes Advisory who consulted on the project and AG Coombes contractors who undertook the installation works.

The project requirements included decommissioning the old boilers and installing the new boilers, with minimal downtime to maintain operational capacity during change over. To assist in this the boilers were pre-fabricated onto skids and then craned into place.

The PowerHT boilers are cascade controlled, with a class leading modulation ratio of 1:9 which allows the boilers to turn down so they only provide the heat output required to meet the heating demand at any time. This eliminates Boiler on/off cycling and greatly increases efficiency. The bank of 4 boilers also provides in-built redundancy as one or more boilers can be taken offline for repairs or maintenance without impacting total system functionality.

The efficiency gains of the new cascade controlled condensing type boiler system over the existing tradiional atmospheric type boiler system are immediate and significant with energy cost savings in excess of 25% forecast.