Influence of heat transfer on the estimation of water vapor diffusion coefficient in transient regime

•Biosourced insulating materials such as wood fiber board are hydrophilic.•A coupled heat and mass transfer model is developed with a limited number of parameters.•The estimation error on the water vapor diffusion coefficient may reach 13% at 35°C if the mass transfer is neglected.•The temperature variation in a wood fiber board due to a change in the relative humidity of the air at the surface can reach 5°C.