Australian Building Ratings Underestimate Energy Use

Speaking at the Climate Research Expo, Annie Egan mentioned that here research on energy performance of Australian office buildings shows they are about 20% less efficient than the energy rating standards, such as NABERS, would indicate. One problem is that NABERS assumes one person per 15 square metres in an office building, while in reality there are 25 to 42 square metres per person. Also the air leakage of building varies widely.

This research suggests one simple way to improve the efficiency of building: reduce air leakage and adjust airflow depending on occupancy. At present Australian buildings are designed to have airflow for the maximum number of people the building can accommodate. As a result there is no need to seal the building, as a lot of airflow is needed anyway. In reality buildings have far fewer people in them most of the time, so need less fresh air. The buildings could therefore be sealed (at low cost with some sealant) and then the airflow adjusted automatically based on occupancy.

For more on this see: The Potential Energy Savings through the use of adaptive comfort cooling setpoints in fully air conditioned Australian office buildings, a simulation study, Aileen (Annie) Egan,

Energy performance simulation of Australian office buildings

My work aims to investigate energy performance simulation of Australian office buildings and look at sources of inaccuracy with these simulations.
Increasingly these simulations are being relied upon to verify that building designs will perform well. So far I have looked at issues such as occupancy, air leakage and weather data.

Annie Egan
College of Engineering and Computer Science