Wangaratta High School: Applied ESD
Posted in Models by Kate Archdeacon on March 10th, 2010
From the Green Building Council Australia Fact Sheet
Wangaratta High School in north-eastern Victoria was awarded a 4 Star Green Star – Education PILOT rating in August 2009 for Stage One in its three part redevelopment plan, becoming the first Green Star certified school in Australia. Utilising environmentally sustainable design (ESD) principles, the Taylor Oppenheim/Meinhardt Group project team aimed to reduce the new senior school’s negative impact on the environment, while at the same time, providing students and teachers with a healthier, more productive space. With US studies revealing green schools foster higher reading retention, better test scores and greater staff retention, it is easy to see why educational facilities around Australia are considering greener alternatives.
Ground heat exchange system
During project consultations, Wangaratta High School and the Victorian Department of Education and Early Childhood Development outlined their vision for the new school to be as energy efficient as possible, reducing the electrical power demand on-site as well as the recurrent energy costs accrued by the school. This brief was realised through the implementation of a ground heat exchange (GHE) system which would service the majority of the facility’s heating and cooling needs. This geothermal technology uses the earth as both a heat source and a heat sink, circulating water in a series of grid loops under the earth’s surface to cool or warm the building above. The system circulates water through a grid of 42 loops extending 100m below, using heat pumps to push the water through hydronic pipes in the building’s floor slab. Because heat energy naturally flows from areas of higher temperature to those of lower temperature, the GHE heating and cooling system is a highly efficient, renewable energy source that maintains a pleasant temperature range of 20-26Â°C throughout the year, with little need for supplementary heating or cooling.
Associate for the Building Science & technology Group at Meinhardt, Dr Mirek Piechowski says: “By tapping into the renewable energy stored in the ground, the GeoExchange technology offers the most energy efficient heat transfer mechanism for climate control system. The other significant feature of the GeoExchange technology is the fact that in the heating mode only up to 25 per cent of the heating energy is derived from fossil fuels, i.e. electricity, while the remaining 75 per cent is renewable energy. In contrast, in traditional gas heating systems 100 per cent of heat is derived from burning gas,” he explains.
A feasibility study conducted by the Meinhardt Group predicted the GHE system would save the school around $35,000 in energy bills, as well as a reduce CO2 emissions by 253 tonnes annually. Combined with other energy efficient measures, this system achieves energy savings of up to 75 per cent, compared to conventional buildings of the same size.
ESD initiatives featured in the project:
* Water efficient fixtures and fittings
* Rainwater collection and reuse for toilet and urinal flushing
* Xeriscape (no applied water) garden
* Vegetated area comprises 30 per cent of the site area for Stage 1
* No evaporative cooling systems used. Heat is rejected via the closed loop geo-exchange system
* Geo-exchange and radiant cooling system
* Natural ventilation
* Solar passive design
* Extensive thermal insulation and double glazing
* Electrical sub-metering provided
* Centralised energy systems through geo-exchange condenser water loop serving multiple buildings
Land Use & Ecology
* Improvement in ecological value of the site
* No topsoil and fill removal from site
* Maximum points obtained from the flooring calculator
* Bicycle facilities provided for staff and students
* Zero ozone depletion refrigerants used
* No Legionella concerns as geo-exchange system avoided the use of cooling towers or evaporative heat rejection equipment
* Innovation point awarded for geo-exchange system in a school application