Heat Loss Via Concrete Slab Floors With External Vertical Edge Insulations

Abstract

A new method was developed and validated against numerical simulations for the calculation of ground heat transfer via floors with vertical edge insulations along the external side of walls. Using the new method, heating and cooling energy demand for two typical houses in the eight capital cities of Australian state and territory were evaluated with different vertical edge insulations and full horizontal floor insulations. It was found that for tropical regions such as Darwin, both vertical edge and full horizontal floor insulation have no or little effect on house heating and cooling energy demand. In cooling dominated climates such as Brisbane, full horizontal floor insulation may increase the total heating and cooling energy demand due to the decoupling between the relatively cool ground and the rooms above. For heating dominated climates such as Melbourne, Canberra and Hobart, ground heat loss can contribute up to around half of the total house heating and cooling energy demand. Full horizontal floor insulation can be very effective in these heating dominated climates. For heating and cooling balanced climates such as Adelaide, Perth and Sydney, vertical edge insulation along the external side of the walls is more effective than full floor insulation.

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Dong Chen

Dong Chen is a principal research scientist at Commonwealth Scientific and Industrial Research Organization (CSIRO) Land and Water. His research interests are physical and numerical modeling of building thermal performance and energy efficiency, and climate change impact on the built environment. He leads the research, development and maintenance of AccuRate, the benchmark building simulation software tool for Nationwide House Energy Rating Scheme (NatHERS) in Australia. He is a member of the NatHERS Technical Advisory Committee.