Thermal conductivity probe length to radius ratio problem when measuring building insulation materials

Thermal conductivity probes are assessed in relation to measuring the effective thermal conductivity of building insulations as samples or in situ. Thermal conductivity and volumetric heat capacity results are given for a range of building insulations, including open and closed cell materials. It was found that the thermal probe technique had potential to be a valuable tool in helping measure, manage and reduce the energy demand of buildings but that traditional solutions for probe length to radius ratios need revision before reliable results can be consistently achieved.

► Identifies various sources of potential error in thermal probe measurements. ► Assesses length to radius ratios in building insulation thermal probe measurements. ► Reports volumetric heat capacity for various insulation materials. ► Provides finite element analyses of thermal probe axial losses.