Retrofit upgrade to Ormond College at Melbourne University. Components of the original heating system dated back the the 1950’s, with the existing single Natural Gas atmospheric 600kW boiler being replaced by 4 x 150kW BAXI Power HT condensing boilers in cascade.
Ormond College occupies 10 acres of land adjoining the University of Melbourne and was built in 1877 by renowned architect Joseph Reed, the designer of many of Melbourne’s important public buildings. The College houses 330 students in single bedrooms, the facilities being used by interstate and foreign students during the year. The College embraced the idea of a new heating power plant with cascade installation for added efficiency, improved heat output and system flexibility. When any of the 4 new boilers require shut down for maintenance the PowerHT plant maintains 75% capacity.
The contractor installed the cascade installation with a primary pump in each boiler which circulates the system water through the hydraulic manifold and separator. The cascade operation is controlled via the temperature regulator for cascade systems (RVA47) with an outdoor sensor set at 21° C with a night set back. All radiators have a thermostatic head except for the common hallways. It is a very simple but reliable system.
For the flue 100mm Stainless Steel was used for each boiler, with the contractor able to reuse the same roof penetration from the old boiler (760mm hole diameter). From the energy use data obtained over subsequent winters the new Power HT cascade system has achieved a significant drop in gas consumption.