This paper investigates the role of moisture content on the measurement of the thermal conductivity of wood-based low-density fibreboards (LDFs) used for building insulation. To that purpose, a computational code of coupled transfers was used to simulate the widely used Heat Flow Meter (HFM) method. To widen the range of study, the thermal conductivity is obtained with a mixing law model to account for the properties and fractions of the constitutive phases. This mix law model was fitted from thermal conductivity values reported for commercial LDFs. The prediction of the heat flow density during the HFM test was compared with the measurements for dry and wet LDF. Through a series of case studies, the simulations showed that, in the case of moist products, the thermal conductivity determined by the HFM method was overestimated by up to 20%. This overestimate depends on the density distribution, thickness, moisture content, and measurement parameters such as time and the equilibrium criterion. Recommendations are made to limit this error.

中文翻译：

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湿生物基隔热建筑材料热流计法的计算表征

本文研究了水分含量对建筑隔热用木质低密度纤维板 (LDF) 导热系数测量的影响。为此，使用耦合传递的计算代码来模拟广泛使用的热流计（HFM）方法。为了扩大研究范围，通过混合定律模型获得热导率，以解释本构相的性质和分数。该混合定律模型根据商业 LDF 报告的热导率值进行拟合。将 HFM 测试期间热流密度的预测与干和湿 LDF 的测量结果进行了比较。通过一系列案例研究，模拟表明，在潮湿产品的情况下，HFM 方法测定的导热系数被高估高达 20%。这种高估取决于密度分布、厚度、水分含量和测量参数（例如时间和平衡标准）。建议限制此错误。