A discussion of "unsaturated cell model of effective thermal conductivity of soils"

In July 2020, this journal published the article "Unsaturated cell model of effective thermal conductivity of soils ", which presented, validated and analysed a cell-based model for predicting the thermal conductivity of unsaturated soils. This discussion however voices a number of concerns on that article. It is revealed that the original cell model underrates the solid thermal conductivity and that it leads to an overly homogeneous impact of the saturation on the effective soil thermal conductivity. This discussion moreover reasons that the correction of the original cell model, reducing it to the - for this situation outdated - Maxwell-Eucken model voids the analysis' novelty, hence invalidating its likely impact on the state-of-the-art.