Abstract
This study evaluates the thermal conductivity of hemp-based insulation materials, focusing on loose bulk mixtures of hemp fibre and hurd. Transient Plane Source (TPS) measurements were employed to assess the thermal conductivity of these materials, with a controlled variation in the fibre-to-hurd ratio and bulk density. Samples from various suppliers, including those with different fibre diameters and hurd contents, were tested. The results indicate thermal conductivities ranging from 0.055 to 0.065 W/mK, demonstrating good insulation performance. This study also highlights the influence of sample compression on thermal conductivity, with higher compression leading to both increased bulk density and thermal conductivity. When compared to the conventional insulation materials glass wool and polystyrene, hemp-based materials exhibited approximately double the thermal conductivity. However, the same thermal resistance (R-value) could be achieved by increasing the thickness of the hemp-based insulation.