Authors: G.M. Soret, J. Tonino, J.L. Torero and M. Aitchison
Optimal thermal performance of buildings is essential to ensure comfort, efficient energy management and environmental sustainability. In Australia, most building components and structures are designed according to criteria and prescriptive thermal design approaches derived from a steady state thermal model. A steady state thermal model is most precise when daily temperature fluctuations remain within a narrow range allowing for detail associated to large seasonal temperature variation. Due to the uniqueness of Australian climate, with potentially larger daily (smaller seasonal) temperature variations, a steady state approach can introduce significant errors when assessing building thermal performance. Herein, we analyze Australian weather data and evaluate both steady and transient state models parameters on case study Australian prefabricated building component systems. Mass-produced housing provides a unique opportunity to conduct this research. We develop a working methodology using analytic and numerical methods complemented by experimental thermal test data. Based on the prefabricated housing case proof-of-concept, this work proposes new prescriptive criteria for building design, which includes daily and seasonal temperature variations and tailors building component system design to its specific geographical locations.
Keywords: Energy efficiency, building thermal performance, Australian building code (BCA), prefab housing, Australian climate, R value, thermal mass, decrement factor, time lag