Application of the Co-heating test in Australian climates

Post construction evaluation of energy efficiency measures is not a mandatory requirement of Australia's National Construction Code. Co-heating tests are one means of conducting post construction evaluation of a buildings’ thermal shell as a complete system. Australia is geographically large, and as such has many different climate zones. Using the Chenath thermal calculation engine, a simulation study was conducted, identifying where and when a Co-heating test can be applied in Australia and provide reliable results. The study compares results across 69 climate zones defined by the Nationwide House Energy Rating Scheme (NatHERS) as well as four different calculation techniques to generate the Heat Transfer Coefficient (HTC) and compares this with an estimated ‘true’ HTC. While the co-heating test is found to provide most reliable results when used in winter, and has a larger window of application in the southern parts of Australia, the test is shown to be accurate in some hotter climates further north. Most reliable results were attained using a two-stage regression analysis. This shows potential for the co-heating test to be applied in Australia.