Studying energy-efficient buildings
Developing sustainable buildings has been a major consideration for AUT University’s recent construction projects, says AUT director, asset development, Suzanne Webb. The new building for the Manukau campus was no different.
During the design process for the new South Campus building, AUT’s architects worked with EECA to use energy efficiency reviews and computer modelling to determine the impact of particular items on the efficiency of the building, Webb says.
“Computer modelling indicates the building currently offers improved energy performance compared to an NZ Building Code reference building,” she says. “This has been calculated at around 30kWh/m2 per year energy savings offered by the building envelope design, and around 70kWh/m2 per year energy savings offered by the building services design”.
In other words, the walls and roof of the building have been highly insulated and the services inside the building have been made incredibly efficient, resulting in a serious energy saving for every square metre of the building. If you base costs on the average price of residential electricity at 26c per kWh, AUT’s new South Campus will save around $7.80 for each external square metre (the walls and the roof) and $18.20 for each internal square metre. And it’s a bloody big building.
So what have they actually done? First, they’ve strategically placed windows and solar shading to make sure the building doesn’t take on too much heat from the sun in summer, reducing the cost of cooling the building with aircon. High spec insulation means the building stays warm naturally in winter, vastly reducing the need to whack on a heat pump.
And in a real cutting edge innovation, AUT is using “displacement ventilation”, where the heating system is in the floor, not the ceiling. Because heat rises, the intelligent heating system is set to heat only the first two metres of any space, while traditional heat pumps spend a lot of energy pushing heat down.
AUT will also fit high efficiency LED lighting, and an ‘ energy sub-metering’ system, which provides a clear breakdown of energy usage to give the team a chance to regularly fine tune the building.