Mount Beauty is a sub-alpine village in North-East Victoria. The Neighbourhood Centre was originally constructed in the 1950’s for the State Electricity Commission and it now provides services to the local community.
The buildings comprise a main building (240m2) and a small separate hall (120m2). Both are painted timber weatherboard, with raised timber floors on stumps.
The original air conditioning was grossly inadequate and limited usage of the Centre, particularly during cold winters when activities were often cancelled, but with GeoExchange the Centre is now open 9am to 10pm for most days of the year.
Mount Beauty has a typical four-season climate, with hot dry summers and cold wet winters. The mean maximum temperature ranges from 29 °C to 11 °C (record high 42.5 °C), while mean minimum daily temperature ranges from 13°C to 2 °C (record low -4°C).
Heating and Cooling
Energy modelling indicated an annual demand of 17.7 MWh for cooling and 17.4 MWh for heating.
The heating set point was taken as 20 °C and the cooling set point as 24 °C. The lower than usual heating temperature recognised the colder winter temperatures in Mount Beauty and the likelihood that visitors would alter their dress sense in winter in response.
The system was also required to supply domestic hot water.
Public areas were required to be conditioned 9am – 10pm seven days a week.
The options considered for the Neighbourhood Centre included:
A 21 kW GeoExchange package was selected for its energy and cost savings and ease of operation in essentially a public domain.
Energy costs and savings are an important part of any air conditioning decision, and they are expected to become more important as energy costs rise.
GeoExchange cuts energy use and operating costs.
The total annual energy consumption, covering both heating and cooling cycles, for the GeoExchange system is less than 1/3rd (27%) of that consumed by the alternative.
The GeoExchange system is nearly twice as efficient as the roof-top package and over five times more efficient than LPG heaters.
The annual cost of operating the GeoExchange air conditioner is less than 30% of the cost of the alternative. This is a saving the Neighbour Centre around $3,200 per year.
The capital cost of the GeoExchange system was higher than that for the alternative. However, when the capital cost and annual operating costs are considered, the simple time to pay back the extra capital cost is about 6 years. Energy Price increases will shorten the pay-back period.
GeoExchange is noted for its reliability and long life. Warranties of 20 years on the ground loops and 5 years on the plant have been provided. The ground loops are anticipated to have a life of more than 50 years and the plant a life of more than 15 years.
Environmental and Safety Performance
GeoExchange is the best environmental option, considering:
We acknowledge Meinhardt Engineers Building Science Group & Dr. Mirek Piechowski whose feasibility study for this project has been incorporated. This case study is subject to a review by Meinhardt.