Measuring the thermal properties of green wood by the transient plane source (TPS) technique

The thermal properties of wood in the green state have been determined by the transient plane source (TPS) technique. Data are presented on thermal conductivity (lambda), heat capacity (C), and thermal diffusivity (kappa) at moisture contents (MCs) above the fiber saturation point, which are based on measurements using the HotDisk (R) apparatus. Four wood species (Douglas fir, beech, birch, and spruce) were tested, and the results are compared with literature data and those obtained by the flash method. A linear relationship was found between the thermal properties lambda, C, and. on the one hand and MC on the other. Equations predicting the thermal values as a function of MC and wood anisotropy are presented. Wood C and lambda increase with MC, but wet wood diffuses heat more rapidly than dry wood.