Heat Loss via Concrete Slab Floors in Australian Houses

Proper evaluation of ground heat loss is important for modern energy efficient residential houses. In this study, a new method was developed for the calculation of ground heat transfer via the floors with vertical edge insulation and validated by three-dimensional numerical simulations. Using a 2.7GHz laptop computer, the calculation of hourly heat losses for one year (8760 hours) using the new method took less than 0.1 milliseconds. The heating and cooling demand for two typical houses in eight Australian state and territory capital cities were then evaluated with vertical floor edge insulation for R0.5 to R2.5. It was found that in relatively cold climates such as Melbourne, Canberra and Hobart, ground heat loss can contribute up to 49% of the total house heating and cooling energy demand. Vertical edge insulation along the external side of the wall can normally reduce around 15% to 25% of this ground heat loss contribution.